photoactivated silicon–oxygen and silicon–nitrogen

doi.org/10.26434/chemrxiv.11441625.v1

Photoactivated Silicon–Oxygen and Silicon–NitrogenHeterodehydrocoupling with a Commercially Available Iron CompoundRory Waterman, Matthew B. Reuter

Submitted date: 23/12/2019 • Posted date: 24/12/2019Licence: CC BY-NC-ND 4.0Citation information: Waterman, Rory; Reuter, Matthew B. (2019): Photoactivated Silicon–Oxygen andSilicon–Nitrogen Heterodehydrocoupling with a Commercially Available Iron Compound. ChemRxiv. Preprint.https://doi.org/10.26434/chemrxiv.11441625.v1

Si–O and Si–N heterodehydrocoupling catalyzed by the commercially available iron dimer (1) underphotochemical conditions is reported. Mechanistic study reveals that the most immediate hurdle in thecatalysis is the poor activation of 1, demonstrating the necessity to fully activate the catalyst to realize thepotential of iron in this reactivity.

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ARTICLE

Received 00th January 20xx,

Accepted 00th January 20xx

DOI: 10.1039/x0xx00000x Photoactivated Silicon–Oxygen and Silicon–Nitrogen Heterodehydrocoupling with a Commercially Available Iron Compound

Matthew B. Reuter, Michael P. Cibuzar, James Hammerton, and Rory Waterman*

Silicon–oxygen and silicon–nitrogen heterodehydrocoupling catalyzed by the commercially available cyclopentadienyl

dicarbonyl iron dimer [CpFe(CO)2]2 (1) under photochemical conditions is reported. Reactions between alcohols and PhSiH3

with catalytic 1 under visible-light irradiation produced silyl ethers quantitively. Reactions between either secondary or

tertiary silanes and alcohols also produced silyl ethers, however, these reactions were marked by their slower longer

reaction times and lower conversions. Reactions of either production from either primary or secondary amines and silanes

with catalytic 1 demonstrated mixed in efficiency, featuring conversions of 20 – 100%. Mechanistic study indicates that an

iron silyl compound is unimportant in the bond–formation step and argues for a nucleophilic alkoxide intermediate. Most

important, mechanistic study reveals that the most immediate hurdle in the catalysis is the poor activation of 1,

demonstrating the necessity to fully activate the catalyst to realize the potential of iron in this reactivity.

University of Vermont, Department of Chemistry, Discovery Hall, Burlington, VT 05401, USA. E-mail: rory.waterman@uvm.edu

† Footnotes relating to the title and/or authors should appear here. Electronic Supplementary Information (ESI) available: [details of any supplementaryinformation available should be included here]. See DOI: 10.1039/x0xx00000x

Please do not adjust margins

ARTICLE Dalton Transactions

Introduction

The dominance of noble metals in catalysis is, rightly, under

assault. The importance of metals such as palladium,

platinum, rhodium, and iridium is irrefutable, with some of

the more significant transformations including palladium–

catalyzed C–C or C–N cross-coupling,1 platinum–catalyzed

hydrosilylation of olefins,2 rhodium–catalyzed

hydrogenation and hydroformylation,3 and iridium–

catalyzed C–H activation.4 Despite their high utility to both

academia and industry, there has been a shift away from

these noble metals due to their cost, toxicity, and most

importantly, increasing scarcity.5 In their stead, a plethora

of transformations have emerged, including C–C cross-

coupling,6 hydrosilylation of olefins and aldehydes,7,8 and C–

H activation,9 by base metals including iron, manganese,

and cobalt. Iron is particularly attractive in catalysis due to

its high abundance and access to a range of oxidation

states.10,11 However, a variety of factors limit base metal–

catalyzed transformations, such as high catalyst loadings,

significant heating, or other forcing conditions to achieve

conversions comparable to those with noble metal

catalysts. Iron is no exception to these limitations, and it is

also noteworthy to mention that examples of mild,

photoactivated iron compounds are scarce in comparison

to thermally activated catalysts.12,13 This becomes an

unfortunate realization, as the development and

improvement of iron–based systems is paramount to

inexpensive and green chemical transformations.

Concomitant with the development of base metal

catalysis, chemists have been challenged with the

development of greener synthetic pathways.

Heterodehydrocoupling has gained momentum in green

chemistry, due to the atom-economical formation of

element–element bonds. The evolution of hydrogen as the

sole by-product is also attractive, providing an excellent

driving force and simplifying purification of products. Most

dehydrocoupling reactions can only be accomplished

catalytically with either a main group or transition–metal

compound.14 Consequentially, heterodehydrocoupling

catalysts are attractive for green, catalytic transformations.

The commercially available iron dimer [CpFe(CO)2]2 (1)

is a rare example that fulfils both previous points.

Heterodehydrocoupling via compound 1 has been already

been demonstrated on amine-borane substrates by

Manners and co-workers as well as between

dimethylformamide and PhMe2SiH by Waterman and co-

workers.15,16 Furthermore, compound 1 is known to

photoactivate under either ultraviolet or visible light

irradiation to produce two equivalents of a 17e- compound,

3, via the all terminal carbonyl intermediate 2 (Scheme 1).17

Thus, the photoirradiation of compound 1 may provide a

green and facile method to forming other element–

element bonds in the main group.

Scheme 1. Photoactivation pathway of compound 1 under either ultravioletor visible-light irradiation.17

Silyl ethers, or small molecules containing Si–O bonds, are

of importance in the protection of alcohols.18 Poly(silyl

ethers) are appealing due their hydrolytic instability in

acidic and basic medium.19 Molecules containing Si–N

bonds such as silamines are well established as bases and

silylating agents in organic syntheses,20 while poly(silazanes)

are sought after for their potential as ceramic precursors.21

Herein, we report 1 as a heterodehydrocoupling catalyst in

the formation of Si–O and Si–N bonds. Mechanistic study of

the reaction indicates nucleophilic attack of a silane by an

intermediate iron-alkoxide or -amide, but more germane to

the further development of iron, complete activation of 1

was not achieved in these reactions, which suggests that

full activation of iron catalyst precursors is an important

pursuit in developing base metal catalysis.

Results and Discussion

Condition OptimizationThis study sought to expand the scope of

heterodehydrocoupling by 1,15,16 initially investigating

coupling of primary silanes and alcohols. An equimolar

amount of nPrOH and PhSiH3 in the presence of 1 mol % of

1 in benzene-d6 solution was irradiated under visible-light

from a commercial LED bulb. After 24 h, the mixture

showed 32% conversion to PhSiH2(OnPr) and 43%

conversion to PhSiH(OnPr)2 as measured by 1H NMR

spectroscopy. The molar equivalences of alcohol and silane

were varied in an effort to generate the third addition silyl

ether product PhSi(OnPr)3. Four-fold excess of silane to one

equivalent of alcohol showed little effect on silyl ether

generation. However, increasing the concentration of

alcohol four-fold and the catalyst loading to 2 mol % of 1

generated PhSi(OnPr)3 in quantitative conversion after 24 h

according to 1H NMR spectroscopy (Table 1, Entry 1).22

These reaction conditions were uniformly applied to other

substrates (Eq. 1).

Catalytic Si-O Heterodehydrocoupling

2 | Dalton Trans ., 2012, 00, 1-3 This journal is © The Royal Society of Chemistry 20xx

Dalton Transactions ARTICLE

Coupling of alcohols such as BnOH (Bn = CH2Ph) andiPrOH with PhSiH3 was also accomplished with 1. Reaction

of BnOH and PhSiH3 in a 4:1 ratio generated PhSi(OBn)3

after 6 h, as determined by 1H and 29Si{1H} NMR

spectroscopy (Table 1, Entry 2).23,24 Reactions betweeniPrOH and PhSiH3 at similar alcohol/silane ratio proceeded

to incomplete conversion from PhSiH3 after 24 h, which

prompted an increase in the alcohol/silane ratio. Reaction

of a 5:1 mixture of iPrOH and PhSiH3 completely converted

from PhSiH3 by 24 h to PhSi(OiPr)3 (Table 1, Entry 3).24,25,26

Attempts at coupling PhSiH3 with heavily encumbered

alcohols such as tBuOH with 1 did not produce silyl ethers

according to 1H NMR spectroscopy.

Heterodehydrocoupling with secondary silanes using

compound 1 was also investigated. Reaction of PhMeSiH2

and nPrOH in a 1:4 ratio generated a single peak at δ -18.07

in 29Si{1H} NMR spectroscopy after 24 h under irradiation,

consistent with PhMeSi(OnPr)2 (Table 1, Entry 4). The final

resonance generated at δ 3.89 in 1H NMR spectroscopy

indicated 100% conversion to PhMeSi(OnPr)2. A similar

strategy was applied to reactions of iPrOH and PhSiH3 in a

5:1 ratio, where PhMeSi(OiPr)2 was afforded in 91%

conversion with 9% of PhMeSiH(OiPr) remaining after 24 h

(Table 1, Entry 6). Reaction of excess BnOH with PhMeSiH2

produced PhMeSi(OBn)2 in 100% conversion after 24 h

(Table 1, Entry 5).27

Reaction of nPrOH and Ph2SiH2 under visible-light irradiation

in the presence of 1 proceeded slowly according to 1H NMR

spectroscopy, but all starting material was consumed to a

single new product. Isolation of pure product from the

highly soluble Fp-catalyst remains a challenge, but in

comparison to similar resonances of known compounds, it

is hypothesized that Ph2Si(OnPr)2 was generated in 100%

conversion (Table 1, Entry 7). Reactions BnOH and Ph2SiH2

in a 4:1 ratio produced Ph2Si(OBn)2 in 100% conversion as

measured by 1H NMR spectroscopy (Table 1, Entry 8).24,28

Interestingly, reacting 5 equiv of iPrOH with Ph2SiH2

exclusively yielded Ph2SiH(OiPr)24 in quantitative conversion

with no evidence of fully substituted product Ph2Si(OiPr)2

(Table 1, Entry 9).24

Reaction of nPrOH and PhMe2SiH in a 5:1 ratio afforded

a new product, tentatively assigned to PhMe2Si(OnPr) based

on analogy to PhMe2Si(OBn) and PhMe2Si(OiPr), in 93%

conversion as a resonance at δ 6.67 in the 29Si{1H} NMR

spectrum (Table 1, Entry 10). Reaction of excess BnOH and

PhMe2SiH, however, showed complete disappearance of

PhMe2SiH in the 1H NMR spectrum and generation of

PhMe2Si(OBn) after 24 h (Table 1, Entry 11).27,29 Reaction ofiPrOH and PhMe2SiH in a 6:1 ratio showed 93% conversion

to PhMe2Si(OiPr) after 24 h according to 1H NMR

spectroscopy (Table 1, Entry 12).30

Table 1. Catalytic conditions for the coupling of alcohols and silanes.a

aConditi ons: 2.0

mol % of 1 under

visible– light

irradiation in benzene-d6 solution at ambient temperature for 24 h. Catalyst loading was with respect to silane. Reactions were monitored by 1H and29Si{1H} NMR spectroscopy. bRefers to mol. of alcohol per mol. of silane. cConversions were determined by 1H NMR integration. dLiterature spectral

data of these silyl ethers have not been previously reported.

Catalytic Si-N Heterodehydrocoupling

This journal is © The Royal Society of Chemistry 20xx Dalton Trans ., 2013, 00, 1-3 | 3

entry silane alcohol equivb product conversion (%)c

1 PhSiH3nPrOH 4.0 PhSi(OnPr)3 100

2 PhSiH3 BnOH 4.0 PhSi(OBn)3 100

3 PhSiH3iPrOH 5.0 PhSi(OiPr)3 100

4 PhMeSiH2nPrOH 4.0 PhMeSi(OnPr)2

5 PhMeSiH2 BnOH 4.0 PhMeSi(OBn)2 100

6 PhMeSiH2iPrOH 5.0

PhMeSiH(OiPr),d PhMeSi(OiPr)2

7 Ph2SiH2nPrOH 4.0 Ph2Si(OnPr)2

8 Ph2SiH2 BnOH 4.0 Ph2Si(OBn)2 100

9 Ph2SiH2iPrOH 5.0 Ph2SiH(OiPr) 100

10 PhMe2SiH nPrOH 5.0 PhMe2Si(OnPr)d 93

11 PhMe2SiH BnOH 5.0 PhMe2Si(OBn) 100

12 PhMe2SiH iPrOH 6.0 PhMe2Si(OiPr) 93

Compound 1 also proved to be competent at Si–N

heterodehydrocoupling but at higher catalyst loadings (Eq.

2). Silamines were produced less efficiently than silyl

ethers, as evident by the overall longer reaction times and

mixture of silamine products.

Treatment of nPrNH2 with PhSiH3 in a 6:1 amine/silane

ratio produced PhSiH2(HNnPr) in only 13% conversion after

4 h by 1H NMR spectroscopy. After 18 h, the reaction

produced PhSiH(HNnPr) in 50% conversion and

PhSiH2(HNnPr) in 23% conversion (Table 2, Entry 1).31

However, the analogous reaction with tBuNH2 and PhSiH3

produced PhSiH2(HNtBu) in 100% after only 4 h according to

1H NMR spectroscopy, and in 24 h, PhSiH2(HNtBu) and

PhSiH(HNtBu) were produced in 89% and 11% conversions

(Table 2, Entry 2).32,33 The disparity between the two amines

indicates that more basic (i.e., nucleophilic) amines give

greater silamine conversions. This observation was

supported by reaction of 4 equiv of iPrNH2 and PhSiH3 to

furnish PhSiH2(HNiPr) in 100% conversion after 20 h

according to 1H NMR spectroscopy (Table 2, Entry 4).34

Moreover, reaction of 4.7 equiv of Et2NH with PhSiH3

produced PhSiH2(NEt2) and PhSiH(NEt2)2 in 29% and 71%

conversions, respectively, after 24 h (Table 2, Entry 5).35

Finally, reaction of 4.6 equiv of PhNH2 with 9.3 mol % of 1,

PhSiH2(HNPh) was afforded in only 20% conversion after 20

h (Table 2, Entry 3).

Table 2. Catalytic conditions for the coupling of amines and silanes.a

entry silane amine loadingb equivc product conversion (%)d time (h)

1 PhSiH3nPrNH2 6.0 3.5

PhSiH2(HNnPr)PhSiH(HNnPr)2

2350 18

2 PhSiH3tBuNH2 7.8 6.0

PhSiH2(HNtBu)PhSiH(HNtBu)2

8911 24

3 PhSiH3 PhNH2 9.3 5.0 PhSiH2(HNPh) 20 20

4 PhSiH3iPrNH2 8.5 4.0 PhSiH2(HNiPr) 100 20

5 PhSiH3 Et2NH 8.5 6.0PhSiH2(NEt2)PhSiH(NEt2)2

2971 24

6 PhMeSiH2nPrNH2 9.3 5.0 PhMeSiH(HNnPr) 60 24

7 PhMeSiH2tBuNH2 7.8 5.0 PhMeSiH(HNtBu) 100 24

8 PhMeSiH2iPrNH2 9.3 4.0 PhMeSiH(HNiPr) 100 24

9 PhMeSiH2 Et2NH 10.2 6.0 PhMeSiH(NEt2) 100 24

10 Ph2SiH2nPrNH2 6.8 3.0 Ph2Si(HNnPr) 74 24

11 Ph2SiH2tBuNH2 8.1 6.0 Ph2Si(HNtBu) 40 24

12 Ph2SiH2iPrNH2 7.8 6.0 Ph2Si(HNiPr) 100 24

13 Ph2SiH2 Et2NH 8.5 7.0 Ph2SiH(NEt2) 22 24

aConditions: visible–light irradiation in benzene-d6 solution at ambient temperature. Reactions were monitored by 1H, 29Si{1H}, and 1H-29Si HSQC NMR

Spectroscopy. bMol % of 1 was with respect to silane. cEquiv of amine per 1 equiv of silane. dConversions were determined by 1H NMR integration.

Compound 1 was also demonstrated to be a competent

heterodehydrocoupling with amines and PhMeSiH2.

Treatment of nPrNH2 with PhMeSiH2 in a 5:1 amine/silane

ratio affords the corresponding silamine PhMeSiH(HNnPr) in

60% conversion after 24 h by 1H NMR spectroscopy (Table

2, Entry 6).34 Meanwhile, PhMeSiH(HNtBu) was generated in

100% conversion by 1H NMR spectroscopy after 24 h (Table

2, Entry 7).34 Furthermore, reacting 4 equiv of iPrNH2 with

PhMeSiH2 quantitatively produced PhMeSiH(HNiPr) after 24

h according to 1H and 1H-29Si HSQC NMR spectroscopy

(Table 2, Entry 8).34 The reaction between Et2NH and

PhMeSiH2 in a 6:1 ratio quantitatively converted from

Dalton Transactions ARTICLE

PhMeSiH2 after 24 h according to 1H and 1H-29Si HSQC NMR

spectroscopy (Table 2, Entry 9).35 Notably, in addition to

PhMeSiH(NEt2), a second peak was also discernible 1H-29Si

HSQC NMR spectroscopy. Although it was initially believed

to be the second addition product PhMeSi(NEt2)2, literature

chemical shifts do not agree,35 and this minor byproduct

remains unidentified.

Finally, heterodehydrocoupling reactions with amines

and Ph2SiH2 catalyzed by compound 1 were also tested.

Reaction between nPrNH2 and Ph2SiH2 showed 74%

conversion to Ph2SiH(HNnPr) after 24 h according to 1H NMR

spectroscopy (Table 2, Entry 10).34 Conversely, reaction

between Ph2SiH2 and tBuNH2 showed only 50% conversion

to Ph2SiH(HNtBu) after 24 h (Table 2, Entry 11).32 The

observations indicated that steric factors can play a more

significant role when both the amine and silane exhibit

steric pressure. Of note, steric factors were more

pronounced with just the alcohol substrate in silyl ether

reactions (vide supra). This supposition is buttressed by the

reaction of Et2NH and Ph2SiH2 in which 22% conversion to

Ph2SiH(NEt2) was observed after 24 h, despite seven

equivalent of amine to silane (Table 2, Entry 13).33 The

balance can be tipped back with amine substitution where

reaction of iPrNH2 and Ph2SiH2 gave nearly quantitative

conversion to Ph2SiH(HNiPr) with a minor byproduct

discernible only in 1H-29Si HSQC NMR (Table 2, Entry 12).35

Mechanistic Study

Treatment of 1 with 1 equiv of nPrOH resulted in no change

as observed by 1H NMR spectroscopy after 24 h of visible-

light irradiation in a benzene-d6 solution. In contrast,

reaction of equimolar 1 and PhSiH3 over 24 h in benzene-d6

under visible–light irradiation resulted in 22% formation of

hydride 4 as measured by 1H NMR spectroscopy (Eq. 3).36 A

new iron compound, tentatively assigned as

Cp(CO)2FeSiH2Ph (5) based on resonances at δ 5.22 (SiH)

and δ 3.98 (C5H5), was observed in 27% conversion. Such

reactivity, the activation of an E–H bond under photolysis of

1 has been observed with phosphines.16

That P–H bond activation was also not quantitative,

doubtlessly related to the kinetics of visible–light activation

of 1.17 The known decomposition of 4 to 1 and the

possibility of a process that directly converts 4 to 5 with

free PhSiH3 likely contribute to the ~20% excess of 5 as

compared to 4. Observation of catalytic reactions with

PhSiH3 by 1H NMR spectroscopy confirm formation of 5

under catalytic conditions as well as apparently unreacted

1. Apparent Si–H bond activation products at iron are

consistently presented in catalytic reactions, regardless of

substrate.

This observation suggests that iron could activate the

organosilane substrate for nucleophilic attack by alcohol. To

test this supposition, a known silyl derivative,

Cp(CO)2FeSiMe2Ph (6) was prepared.37 Treatment of 6 with

1 equiv of nPrOH failed to afford the anticipated silyl ether

to any detectable extent by 1H NMR spectroscopy, and

variations on the reaction including 10 equiv of alcohol,

irradiation, or heating failed to afford silyl ether as well.

These observations demonstrate that the silyl derivative is

an off-cycle spectator, affirming the long-standing

observation that visible “intermediates” are not necessarily

catalytically relevant and that unseen compounds are often

the critical and active intermediates.38

Despite these negative results, the persistence of 1 and

silyl derivatives like 5 at the end of catalysis indicate that

the iron compound is largely preserved. Therefore, active

compounds are formally 18-electron derivatives,

Cp(CO)2FeX (X = silyl, hydride, alkoxide, etc.). Such

compounds are unavailable for organometallic (i.e.,

oxidative addition or σ-bond metathesis) steps due to

formal electron counts and the inaccessibility of these X

ligands for migratory insertion with carbonyl ligands.39,40

Such deduction leaves nucleophilic attack as the most

viable mechanistic hypothesis. Many metals promote

nucleophilicity of ligands.41 While we cannot observe an

iron alkoxide compound in solution, we cannot discount it.

Such an intermediate would be more nucleophilic than its

parent alcohol. Indeed, the relative reactivity of aniline and

iPrNH2 support nucleophilicity at the coupling partner.

While literature on isolated piano-stool iron alkoxides or

amidos is scarce, Nakazawa and coworkers have implicated

piano-stool iron-alkoxide and iron-thio intermediates in

catalytic silicon-oxygen and silicon-sulfur

heterodehydrocoupling, respectively.42,43

Scheme 2. Proposed mechanism for Si–O and Si–N heterodehydrocouplingcatalysed by 1.

Based on the stoichiometric reactions and observations

of the catalysis, an initial proposal for the catalytic cycle can

be made (Scheme 2). From both stoichiometric and

catalytic reactions, it is clear that the activation of 1 is not

complete, but irradiation would form two equiv of 3, which

would active silane substrate to hydride 4 and a silyl

compound. The silyl compound is an inactive spectator that

may be converted to 4 as hydrogen is evolved. Hydride 4

can decompose back to 1, which may also contribute to the

steady state concentration of 1 during catalysis as observed

by 1H NMR spectroscopy. However, 4 likely reacts with

alcohol to give a highly unstable alkoxide intermediate with

evolution of hydrogen. This alkoxide intermediate can then

attack a silane substrate to form product and regenerate 4.

Perhaps the most important observation from this

mechanistic proposal is not the Si–O or Si–N, bond-forming

step. There is far less active catalyst in the system than the

loading of 1 would indicate, even if the silyl intermediate

were completely inactive under catalytic conditions. This

information is a clear indication that a meager fraction of

potential activity is being realized.

Conclusions

A commercially available iron compound 1 is efficient at Si–

O heterodehydrocoupling under visible-light irradiation.

Reactions between alcohols and silanes catalyzed by 1

afforded silyl ether often in quantitative conversions from

starting silanes. Sterically encumbered silanes generally

required longer reaction times but provided near

quantitative conversion from starting silanes. Compound 1

is also a competent Si–N heterodehydrocoupling catalyst.

However, longer reaction times and higher catalyst loadings

were necessary to produce silamines in good conversions.

Furthermore, electron–rich amines were shown to be the

most effective substrates to convert to silamines.

Mechanistic study is consistent with nucleophilic attack of

an intermediate iron–alkoxide or –amide at the

organosilanes substrate. More important to future study,

though, is the necessity for complete activation of catalyst

to achieve optimal conversions. The ‘unactivated’ fraction

of catalyst may be a significant factor in the disparity

between base and noble metals in catalysis, suggesting an

area for deeper investigation. More specifically, this work

expands upon the heterodehydrocoupling capabilities of

1,15,16 and represents one of the few instances of mild, light-

activated iron-based catalysts.

Experimental

General Information

All reactions were prepared under purified a N2

atmosphere in an M. Braun glovebox. Cyclopentadienyl

dicarbonyl iron (II) dimer 1 was purified by sublimation.

Alcohols and amines were distilled from CaH2. Silanes were

used without further purification. Benzene-d6 was vacuum

transferred from NaK alloy. NMR spectra were acquired on

either a Varian 500 MHz spectrometer or a Bruker AXR 500

MHz spectrometer. Spectra recorded on both instruments

were reported to TMS (δ 0.00).

Catalytic Experiment Conditions

An oven-dried scintillation vial containing 1 (3.5 mg, 2.0

mol %) was charged with silane, followed by excess alcohol,

0.5 mL benzene-d6, and TMS. A similar method was

performed with amine coupling, however, loading of 1 was

determined by substrates. Mixtures were transferred to a J-

Young type polytetrafluoroethylene-valved NMR tube and

subsequently placed under visible-light irradiation.

Reactions were subjected to a cycle of freeze-pump-thaw

after 1 and 2 h of irradiation. All reactions were performed

at ambient temperature under irradiation in the visible

spectrum using a 40 W LED bulb.

Conflicts of interest

The authors have no conflicts of interest to declare.

Acknowledgements

This work was funded by the National Science Foundation

through CHE-1565658. The authors would like to thank Dr.

Monika Ivancic for assistance with NMR spectra.

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Supporting Information for

Photoactivated Silicon-Oxygen and Silicon-Nitrogen Heterodehydrocoupling with a

Commercially Available Iron Compound

Matthew B. Reuter, Michael P. Cibuzar, James Hammerton, and Rory Waterman*

Department of Chemistry, University of Vermont, Burlington, VT 05045-0125

Rory.Waterman@uvm.edu

Contents General Information ................................................................................................................................. S2

Catalytic Experiment Conditions ............................................................................................................ S2

Spectroscopic Intermediates .................................................................................................................... S6

Catalytic Silicon-Oxygen Heterodehydrocoupling............................................................................... S12

PhSiH3 and nPrOH .............................................................................................................................. S12

PhSiH3 and BnOH. .............................................................................................................................. S15

PhSiH3 and iPrOH. .............................................................................................................................. S18

PhMeSiH2 and nPrOH ........................................................................................................................ S21

PhMeSiH2 and BnOH. ........................................................................................................................ S24

PhMeSiH2 and iPrOH ......................................................................................................................... S27

Ph2SiH2 and nPrOH. ............................................................................................................................ S31

Ph2SiH2 and BnOH ............................................................................................................................. S34

Ph2SiH2 and iPrOH ............................................................................................................................. S37

PhMe2SiH and nPrOH ........................................................................................................................ S40

PhMe2SiH and BnOH ......................................................................................................................... S43

PhMe2SiH and iPrOH ......................................................................................................................... S46

Catalytic Silicon-Nitrogen Heterodehydrocoupling............................................................................. S49

PhSiH3 and nPrNH2 ............................................................................................................................. S49

PhSiH3 and tBuNH2. ............................................................................................................................ S52

PhSiH3 and PhNH2 .............................................................................................................................. S55

PhSiH3 and iPrNH2.............................................................................................................................. S58

PhSiH3 and Et2NH .............................................................................................................................. S61

PhMeSiH2 and nPrNH2 ....................................................................................................................... S64

PhMeSiH2 and tBuNH2 ....................................................................................................................... S67

PhMeSiH2 and iPrNH2 ........................................................................................................................ S70

PhMeSiH2 and Et2NH ......................................................................................................................... S73

Ph2SiH2 and nPrNH2............................................................................................................................ S76

Ph2SiH2 and tBuNH2 ............................................................................................................................ S79

Ph2SiH2 and iPrNH2 ............................................................................................................................ S82

Ph2SiH2 and Et2NH ............................................................................................................................. S85

General Information

All reactions were prepared under purified a N2 atmosphere in an M. Braun glovebox.

Cyclopentadienyl dicarbonyl iron (II) dimer 1 was purified by sublimation. Alcohols and amines

were distilled from CaH2. Silanes were used without further purification. Benzene-d6 was vacuum

transferred from NaK alloy. NMR spectra were acquired on either a Varian 500 MHz spectrometer

or a Bruker AXR 500 MHz spectrometer. Spectra recorded on both instruments were reported to

TMS (δ 0.00) for 1H and 29Si NMR.

Catalytic Experiment Conditions

An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was charged with silane,

followed by excess alcohol, 0.5 mL benzene-d6, and TMS. A similar method was performed with

amine coupling, however, loading of 1 was determined by substrates. Mixtures were transferred

to a J-Young type polytetrafluoroethylene-valved NMR tube and subsequently placed under

visible-light irradiation. Reactions were subjected to a cycle of freeze-pump-thaw after 1 and 2 h

of irradiation. All reactions were performed at ambient temperature under irradiation in the visible

spectrum using a 40 W LED bulb.

Figure S.1 LED Reactor for Photocatalysis

Table S1. Experimental and Literature NMR Characterization Data for Silyl Ethers.

Entry Compound 1H NMR (Lit) 29Si NMR (Lit) References

1 PhSi(OnPr)3 3.79a (3.84)b -57.99a 1

2 PhSi(OBn)3 4.84a (4.855)a -56.24a (-56.4)a 2, 3

3 PhSiH(OiPr)2 5.28a (5.19)a -34.52a (-34.8)a 4

4 PhSi(OiPr)3 4.32a (4.30-4.22)b -61.79a (-61.8)a 5, 3

5 PhMeSi(OnPr)2 3.67a -18.11a 6 PhMeSi(OBn)2 4.71a (4.91-4.82)b -15.48a 6

7 PhMeSiH(OiPr) 5.21a -6.65a 8 PhMeSi(OiPr)2 4.02a -21.83a 9 Ph2SiH(OnPr) 5.63a N/A 10 Ph2Si(OnPr)2 3.72a -32.20a 11 Ph2Si(OBn)2 4.79a (4.75)a -29.89a (-30.82)a 7, 3

12 Ph2SiH(OiPr) 5.64a (5.70)a -14.74a (-14.81a) 3

13 PhMe2Si(OnPr) 3.47a 6.66a 14 PhMe2Si(OBn) 4.56a (4.77)b 9.03a (8.9)b 6, 8

15 PhMe2Si(OiPr) 4.01a (4.111-4.030)b 4.21a 9

a in C6D6.

b in CDCl3. N.R. = Not Reported.

Table S2. Experimental and Literature NMR Characterization Data for Silamines.

Entry Compound 1H NMR (Lit) 29Si NMR (Lit) Reference

16 PhSiH2(HNnPr) 5.08a -29.83a 17 PhSiH(HNnPr)2 5.17a (4.87)a -26.57a (-24.13) 10

18 PhSiH2(HNtBu) 5.09a (5.12)a -37.95a (-37.36)a 11

19 PhSiH(HNtBu)2 5.45a (5.23-5.22)a N/A (-30.61)a 12

20 PhSiH2(HNPh) 4.99a -36.77a 21 PhSiH2(HNiPr) 5.20a (5.19)a -30.8a (-38.22)a 13

22 PhSiH2(NEt2) 5.13a (5.10)a -25.20a (-25.44)a 14

23 PhSiH(NEt2)2 5.11a (5.13)a -18.95a (-19.18)a 14

24 PhMeSiH(HNnPr) 5.12a (5.15)a -14.61a (-14.23)a 13

25 PhMeSiH(HNtBu) 5.20a (5.23)a -21.35a (-21.33)a 13

26 PhMeSiH(HNiPr) 5.14a (5.16)a -16.95a (-16.82)a 13

27 PhMeSiH(NEt2) 5.09a (5.08)a -11.07a (-10.98)a 14

28 Ph2SiH(HNnPr) 5.57a (5.61)a -17.78a (-17.29)a 13

29 Ph2SiH(HNtBu) 5.68a (5.70)a -25.06a (-24.86)a 14

30 Ph2SiH(HNiPr) 5.60a (5.63)a -20.14a (-20.26)a 12

31 Ph2SiH(NEt2) 5.55a (5.55)a -14.35a (-14.27)a 14

a in C6D6. N.R. = Not Reported.

Spectroscopic Intermediates

PhSiH3 and 1. An oven-dried scintillation vial containing 1 (35.3 mg, 0.1 mmol) was charged

with an equivalent of PhSiH3 (12.5 μL, 11.0 mg, 0.1 mmol), followed by 1.0 mL benzene-d6. The

mixture was transferred to a J-Young type polytetrafluoroethylene-valved NMR tube and

subsequently placed under visible-light irradiation. After a 1H NMR spectrum was taken after 24

h, an equimolar amount of nPrOH (7.5 μL, 6.0 mg, 0.1 mmol) was added, and the mixture was

irradiated for an additional 24 h.

Figure S.2 1H NMR spectrum of the stoichiometric reaction between PhSiH3 and 1 (benzene-d6,

500 MHz)

Figure S.3 1H NMR spectrum of the stoichiometric reaction between PhSiH3 and 1 after added nPrOH (benzene-d6, 500 MHz)

nPrOH and 1 under H2. An oven-dried scintillation vial containing 1 (35.3 mg, 0.1 mmol) was

charged with an equivalent of nPrOH (7.5 μL, 6.0 mg, 0.1 mmol), followed by 0.5 mL benzene-d6.

The mixture was transferred to a J-Young type polytetrafluoroethylene-valved NMR tube and

subsequently subjected to a cycle of freeze-pump-thaw. After an initial 1H NMR spectrum was

taken, the mixture was placed under hydrogen. After 1 h, an equimolar amount of PhSiH3 (12.5

μL, 11.0 mg, 0.1 mmol) was added and the mixture was left to react for 15 h.

Figure S.4 1H NMR spectrum of the stoichiometric reaction between nPrOH and 1 under H2

(benzene-d6, 500 MHz)

Figure S.5 1H NMR spectrum of the stoichiometric reaction between nPrOH and 1 under H2 after

added PhSiH3 (benzene-d6, 500 MHz)

nPrOH and 6. An oven-dried scintillation vial containing 6 (64.1 mg, 2.3 mmol) was charged with

an equivalent of nPrOH (17 μL, 13.6 mg, 2.3 mmol), followed by 0.5 mL benzene-d6. The mixture

was transferred to a J-Young type polytetrafluoroethylene-valved NMR tube.

Figure S.6 1H NMR spectrum of the stoichiometric reaction between nPrOH and 6 (benzene-d6,

99 MHz)

Figure S.7 1H NMR spectrum of the stoichiometric reaction between nPrOH and 6 (benzene-d6,

99 MHz)

Catalytic Silicon-Oxygen Heterodehydrocoupling

PhSiH3 and nPrOH.1 An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was

charged with PhSiH3 (61.5 μL, 54.0 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, nPrOH (150.0

μL, 120.4 mg, 2.0 mmol), and TMS (17.0 μL, 11.0 mg, 25.0 mol %). The mixture was transferred

to a J-Young type polytetrafluoroethylene-valved NMR tube. After an initial 1H NMR spectrum

was collected, the reaction was irradiated under visible light. The reaction was subjected to a cycle

of freeze-pump-thaw after 1 and 2 h of irradiation. After 24 h, the reaction showed 100%

conversion to PhSi(OnPr)3 as measured by 1H NMR spectroscopy.

Figure S.8 Stacked 1H NMR spectra of the reaction between PhSiH3 and nPrOH catalyzed by 1

Figure S.9 Stacked 1H NMR spectra of the reaction between PhSiH3 and nPrOH catalyzed by 1

Figure S.10 29Si{1H} NMR spectrum of the reaction between PhSiH3 and nPrOH catalyzed by 1

*This artefact is resultant from the 29Si NMR probe and the borosilicate glass from the J-Young

NMR tube

PhSiH3 and BnOH.2,3 An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was

charged with PhSiH3 (61.5 μL, 54.0 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, BnOH (210.0

μL, 219.2 mg, 2.0 mmol), and TMS (17.0 μL, 11.0 mg, 25.0 mol %). After 6 h of irradiation, the

reaction showed 100% conversion to PhSi(OBn)3 as measured by 1H NMR spectroscopy.

Figure S.11 Stacked 1H NMR spectra of the reaction between PhSiH3 and BnOH catalyzed by 1

Figure S.12 Stacked 1H NMR spectra of the reaction between PhSiH3 and BnOH catalyzed by 1

Figure S.13 29Si{1H} NMR spectrum of the reaction between PhSiH3 and BnOH catalyzed by 1

PhSiH3 and iPrOH.4,3,5 An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was

charged with PhSiH3 (61.5 μL, 54.0 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, iPrOH (190.0

reaction showed 100% conversion to PhSi(OiPr)3 as measured by 1H NMR spectroscopy.

Figure S.14 Stacked 1H NMR spectra of the reaction between PhSiH3 and iPrOH catalyzed by 1

Figure S.15 1H NMR spectrum of the reaction between PhSiH3 and iPrOH catalyzed by 1

Figure S.16 29Si{1H} NMR spectrum of the reaction between PhSiH3 and iPrOH catalyzed by 1

PhMeSiH2 and nPrOH. An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was

charged with PhMeSiH2 (68.5 μL, 60.9 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, nPrOH

(150.0 μL, 120.4 mg, 2.0 mmol), and TMS (11.5 μL, 7.4 mg, 16.9 mol %). After 24 h of irradiation,

the reaction demonstrated 100% conversion from PhMeSiH2 as measured by 1H NMR

spectroscopy. Although product isolation was unsuccessful, it was hypothesized that the resonance

at δ 3.67 was PhMeSi(OnPr)2 and was produced in 100% conversion.

Figure S.17 Stacked 1H NMR spectra of the reaction between PhMeSiH2 and nPrOH catalyzed by

1 (benzene-d6, 500 MHz)

Figure S.18 1H NMR spectrum of the reaction between PhMeSiH2 and nPrOH catalyzed by 1

Figure S.19 29Si{1H} NMR spectrum of the reaction between PhMeSiH2 and nPrOH catalyzed by

PhMeSiH2 and BnOH.6 An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was

charged with PhMeSiH2 (68.5 μL, 60.9 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, BnOH

the reaction showed 100% conversion to PhMeSi(OBn)2 as measured by 1H NMR spectroscopy.

Figure S.20 Stacked 1H NMR spectra of the reaction between PhMeSiH2 and BnOH catalyzed by

Figure S.21 1H NMR spectrum of the reaction between PhMeSiH2 and BnOH catalyzed by 1

Figure S.22 29Si{1H} NMR spectrum of the reaction between PhMeSiH2 and BnOH catalyzed by

PhMeSiH2 and iPrOH. An oven-dried scintillation vial containing 1 (3.5 g, 2.0 mol %) was

charged with PhMeSiH2 (68.5 μL, 60.9 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, iPrOH

(190.0 μL, 149.3 mg, 2.5 mmol), and TMS (11.5 μL, 7.4 mg, 16.9 mol %). Although product

isolation was unsuccessful, it was hypothesized that the resonance at δ 5.20 corresponded to

PhMeSiH(OiPr) and was produced in 9% conversion, while the resonance at δ 4.27 corresponded

to the PhMeSi(OiPr)2 and was produced in 91% yield, as measured by 1H NMR spectroscopy.

Figure S.23 Stacked 1H NMR spectra of the reaction between PhMeSiH2 and iPrOH catalyzed by

Figure S.24 1H NMR spectrum of the reaction between PhMeSiH2 and iPrOH catalyzed by 1

Figure S.25 29Si{1H} NMR spectrum of the reaction between PhMeSiH2 and iPrOH catalyzed by

Figure S.26 1H-29Si{1H} HSQC spectrum of the reaction between PhMeSiH2 and iPrOH catalyzed

by 1 (benzene-d6, 99 MHz)

Ph2SiH2 and nPrOH. An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was

charged with Ph2SiH2 (93.0 μL, 92.3 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, nPrOH

the reaction reached 100% conversion from Ph2SiH2 according to 1H NMR spectroscopy.

Although product isolation was unsuccessful, it was hypothesized that the resonance at δ 3.72

corresponds to Ph2Si(OnPr)2 and was produced in 100% conversion.

Figure S.27 Stacked 1H NMR spectra of the reaction between Ph2SiH2 and nPrOH catalyzed by 1

Figure S.28 1H NMR spectrum of the reaction between Ph2SiH2 and nPrOH catalyzed by 1

Figure S.29 29Si{1H} NMR spectrum of the reaction between Ph2SiH2 and nPrOH catalyzed by 1

Ph2SiH2 and BnOH.7,3 An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was

charged with Ph2SiH2 (93.0 μL, 92.3 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, BnOH

the reaction showed 100% conversion to Ph2Si(OBn)2 according to 1H NMR spectroscopy.

Figure S.30 Stacked 1H NMR spectra of the reaction between Ph2SiH2 and BnOH catalyzed by 1

Figure S.31 1H NMR spectrum of the reaction between Ph2SiH2 and BnOH catalyzed by 1

Figure S.32 29Si{1H} NMR spectrum of the reaction between Ph2SiH2 and BnOH catalyzed by 1

Ph2SiH2 and iPrOH.3 An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was

charged with Ph2SiH2 (93.0 μL, 92.3 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, iPrOH (190.0

reaction showed 100% conversion to Ph2SiH(OiPr) according to 1H NMR spectroscopy.

Figure S.33 Stacked 1H NMR spectra of the reaction between Ph2SiH2 and iPrOH catalyzed by 1

Figure S.34 1H NMR spectrum of the reaction between Ph2SiH2 and iPrOH catalyzed by 1

Figure S.35 29Si{1H} NMR spectrum of the reaction between Ph2SiH2 and iPrOH catalyzed by 1

PhMe2SiH and nPrOH. An oven-dried scintillation vial containing 1 (3.5 mg, 2.0 mol %) was

charged with PhMe2SiH (76.5 μL, 68.0 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, nPrOH

the reaction showed partial disappearance of PhMe2SiH at δ 4.60 according to 1H NMR

spectroscopy. It was hypothesized that the peak at δ 3.47 was PhMe2Si(OnPr) and was produced

in 93% conversion.

Figure S.36 Stacked 1H NMR spectra of the reaction between PhMe2SiH and nPrOH catalyzed by

Figure S.37 1H NMR spectrum of the reaction between PhMe2SiH and nPrOH catalyzed by 1

Figure S.38 29Si{1H} NMR spectrum of the reaction between PhMe2SiH and nPrOH catalyzed by

PhMe2SiH and BnOH.6,8 An oven-dried scintillation vial containing 1 (3.6 mg, 2.0 mol %) was

charged with PhMe2SiH (76.5 μL, 68.0 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, BnOH

the reaction showed 100% conversion to PhMe2Si(OBn) according to 1H NMR spectroscopy.

Figure S.39 Stacked 1H NMR spectra of the reaction between PhMe2SiH and BnOH catalyzed by

Figure S.40 1H NMR spectrum of the reaction between PhMe2SiH and BnOH catalyzed by 1

Figure S.41 29Si{1H} NMR spectrum of the reaction between PhMe2SiH and BnOH catalyzed by

PhMe2SiH and iPrOH.9 An oven-dried scintillation vial containing 1 (3.6 mg, 2.0 mol %) was

charged with PhMe2SiH (76.5 μL, 68.0 mg, 0.5 mmol), followed by 0.5 mL benzene-d6, iPrOH

the reaction showed 93% conversion to PhMe2Si(OiPr) according to 1H NMR spectroscopy.

Figure S.42 Stacked 1H NMR spectra of the reaction between PhMe2SiH and iPrOH catalyzed by

Figure S.43 1H NMR spectrum of the reaction between PhMe2SiH and iPrOH catalyzed by 1

Figure S.44 29Si{1H} NMR spectrum of the reaction between PhMe2SiH and iPrOH catalyzed by

Catalytic Silicon-Nitrogen Heterodehydrocoupling

PhSiH3 and nPrNH2.10 An oven-dried scintillation vial containing 1 (3.6 mg, 6.0 mol %) was

charged with PhSiH3 (18.7 mg, 0.2 mmol), followed by 0.5 mL benzene-d6, nPrNH2 (41.8 mg, 0.7

mmol), and TMS (8.4 mg, 56.0 mol %). After 18 h of irradiation, it was hypothesized that the

resonance at δ 5.08 was PhSiH2(HNnPr) and was produced in 23% conversion, and the resonance

at δ 5.17 was PhSiH(HNnPr)2 and was produced in 50% yield. A 1H NMR spectrum was taken at

24 h and showed significant broadening to the point where resonances at δ 5.08 and δ 5.17 were

indistinguishable.

Figure S.45 Stacked 1H NMR spectra of the reaction between PhSiH3 and nPrNH2 catalyzed by 1

Figure S.46 1H NMR spectrum of the reaction between PhSiH3 and nPrNH2 catalyzed by 1

Figure S.47 1H-29Si{1H} HSQC spectra of the reaction between PhSiH3 and nPrNH2 catalyzed

PhSiH3 and tBuNH2.11,12 An oven-dried scintillation vial containing 1 (3.6 mg, 7.8 mol %) was

charged with PhSiH3 (14.3 mg, 0.1 mmol), followed by 0.5 mL benzene-d6, tBuNH2 (42.2 mg, 0.6

mmol), and TMS (7.3 mg, 64.0 mol %). After 24 h of irradiation, the mixture showed 89%

conversion to PhSiH2(HNtBu) and 11% conversion to PhSiH(HNtBu)2 according to 1H NMR

spectroscopy.

Figure S.48 Stacked 1H NMR spectra of the reaction between PhSiH3 and tBuNH2 catalyzed by 1

Figure S.49 1H NMR spectrum of the reaction between PhSiH3 and tBuNH2 catalyzed by 1

Figure S.50 29Si{1H} NMR spectrum of the reaction between PhSiH3 and tBuNH2 catalyzed by 1

PhSiH3 and PhNH2. An oven-dried scintillation vial containing 1 (3.6 mg, 9.3 mol %) was

charged with PhSiH3 (11.9 mg, 0.1 mmol), followed by 0.5 mL benzene-d6, PhNH2 (47.0 mg, 0.5

resonance at δ 5.07 was PhSiH2(HNPh) which was produced in 20% conversion according to 1H

NMR spectroscopy.

Figure S.51 Stacked 1H NMR spectra of the reaction between PhSiH3 and PhNH2 catalyzed by 1

Figure S.52 1H NMR spectrum of the reaction between PhSiH3 and PhNH2 catalyzed by 1

Figure S.53 1H-29Si{1H} HSQC spectra of the reaction between PhSiH3 and PhNH2 catalyzed by

PhSiH3 and iPrNH2.13 An oven-dried scintillation vial containing 1 (3.6 mg, 8.5 mol %) was

charged with PhSiH3 (13.5 mg, 0.1 mmol), followed by 0.5 mL benzene-d6, iPrNH2 (26.3 mg, 0.4

conversion to PhSiH2(HNiPr) according to 1H NMR spectroscopy.

Figure S.54 Stacked 1H NMR spectra of the reaction between PhSiH3 and iPrNH2 catalyzed by 1

Figure S.55 1H NMR spectrum of the reaction between PhSiH3 and iPrNH2 catalyzed by 1

Figure S.56 1H-29Si{1H} HSQC spectra of the reaction between PhSiH3 and iPrNH2 catalyzed by

PhSiH3 and Et2NH.14 An oven-dried scintillation vial containing 1 (3.6 mg, 8.5 mol %) was

charged with PhSiH3 (12.8 mg, 0.1 mmol), followed by 0.5 mL benzene-d6, Et2NH (41.5 mg, 0.6

conversion to PhSiH2(NEt2) and 71% conversion to PhSiH(NEt2)2 according to 1H NMR

spectroscopy.

Figure S.57 Stacked 1H NMR spectra of the reaction between PhSiH3 and Et2NH catalyzed by 1

Figure S.58 1H NMR spectrum of the reaction between PhSiH3 and Et2NH catalyzed by 1

Figure S.59 1H-29Si{1H} HSQC spectra of the reaction between PhSiH3 and Et2NH catalyzed by

PhMeSiH2 and nPrNH2.13 An oven-dried scintillation vial containing 1 (3.6 mg, 9.3 mol %) was

charged with PhMeSiH2 (13.2 mg, 0.1 mmol), followed by 0.5 mL benzene-d6, nPrNH2 (27.5 g,

0.5 mmol), and TMS (6.2 mg, 64.0 mol %). After 24 h of irradiation, the mixture showed 60%

conversion to PhMeSiH(HNnPr) according to 1H NMR spectroscopy.

Figure S.60 Stacked 1H NMR spectra of the reaction between PhMeSiH2 and nPrNH2 catalyzed

Figure S.61 1H NMR spectrum of the reaction between PhMeSiH2 and nPrNH2 catalyzed by 1

Figure S.62 1H-29Si{1H} HSQC spectra of the reaction between PhMeSiH2 and nPrNH2 catalyzed

PhMeSiH2 and tBuNH2.13 An oven-dried scintillation vial containing 1 (3.6 mg, 7.8 mol %) was

charged with PhMeSiH2 (15.7 mg, 0.1 mmol), followed by 0.5 mL benzene-d6, tBuNH2 (39.1 mg,

0.5 mmol), and TMS (5.3 mg, 46.2 mol %). After 24 h of irradiation, the reaction showed 100%

conversion to PhMeSiH(HNtBu) according to 1H NMR spectroscopy.

Figure S.63 Stacked 1H NMR spectra of the reaction between PhMeSiH2 and tBuNH2 catalyzed

Figure S.64 1H NMR spectrum of the reaction between PhMeSiH2 and tBuNH2 catalyzed by 1

Figure S.65 1H-29Si{1H} HSQC spectra of the reaction between PhMeSiH2 and tBuNH2 catalyzed

PhMeSiH2 and iPrNH2.13 An oven-dried scintillation vial containing 1 (3.6 mg, 9.3 mol %) was

charged with PhMeSiH2 (13.5 g, 0.1 mmol) followed by 0.5 mL benzene-d6, iPrNH2 (26.3 mg, 0.4

reaction reached 100% conversion from PhMeSiH2 according to 1H NMR spectroscopy.

Figure S.66 Stacked 1H NMR spectra of the reaction between PhMeSiH2 and iPrNH2 catalyzed by

Figure S.67 1H NMR spectrum of the reaction between PhMeSiH2 and iPrNH2 catalyzed by 1

Figure S.68 1H-29Si{1H} HSQC spectra of the reaction between PhMeSiH2 and iPrNH2 catalyzed

PhMeSiH2 and Et2NH.14 An oven-dried scintillation vial containing 1 (3.6 mg, 10.2 mol %) was

charged with PhMeSiH2 (12.8 mg, 0.1 mmol), followed by 0.5 mL benzene-d6, Et2NH (41.5 mg,

conversion from PhMeSiH2 according to 1H NMR spectroscopy.

Figure S.69 Stacked 1H NMR spectra of the reaction between PhMeSiH2 and Et2NH catalyzed by

Figure S.70 1H NMR spectrum of the reaction between PhMeSiH2 and Et2NH catalyzed by 1

Figure S.71 1H-29Si{1H} HSQC spectra of the reaction between PhMeSiH2 and Et2NH catalyzed

Ph2SiH2 and nPrNH2.13 An oven-dried scintillation vial containing 1 (3.6 mg, 6.8 mol %) was

charged with Ph2SiH2 (28.4 mg, 0.2 mmol), followed by 0.5 mL benzene-d6, nPrNH2 (37.0 mg, 0.6

mmol), and TMS (5.2 mg, 39.3 mol %). After 24 h of irradiation, the reaction showed 74%

conversion to Ph2SiH(HNnPr) according to 1H NMR spectroscopy.

Figure S.72 Stacked 1H NMR spectra of the reaction between Ph2SiH2 and nPrNH2 catalyzed by

Figure S.73 1H NMR spectrum of the reaction between Ph2SiH2 and nPrNH2 catalyzed by 1

Figure S.74 1H-29Si{1H} HSQC spectra of the reaction between Ph2SiH2 and nPrNH2 catalyzed by

Ph2SiH2 and tBuNH2.14 An oven-dried scintillation vial containing 1 (4.0 mg, 8.1 mol %) was

charged with Ph2SiH2 (25.1 mg, 0.1 mmol), followed by 0.5 mL benzene-d6, tBuNH2 (45.8 mg,

conversion to Ph2SiH(HNtBu) according to 1H NMR spectroscopy.

Figure S.75 Stacked 1H NMR spectra of the reaction between Ph2SiH2 and tBuNH2 catalyzed by

Figure S.76 1H NMR spectrum of the reaction between Ph2SiH2 and tBuNH2 catalyzed by 1

Figure S.77 1H-29Si{1H} HSQC spectra of the reaction between Ph2SiH2 and tBuNH2 catalyzed

Ph2SiH2 and iPrNH2.12 An oven-dried scintillation vial containing 1 (3.6 mg, 7.8 mol %) was

charged with Ph2SiH2 (23.3 mg, 0.1 mmol), followed by 0.5 mL benzene-d6, iPrNH2 (36.3 mg, 0.6

mmol), and TMS (5.5 mg, 48.0 mol %). After 24 h of irradiation, the reaction had reached 100%

conversion from Ph2SiH2 according to 1H NMR spectroscopy. However, in addition to

Ph2SiH(HNiPr) at δ -20.14 shown in 1H-29Si HSQC, a second signal appeared at δ -21.76. Although

this was hypothesized to be Ph2Si(HNiPr)2, the 29Si NMR chemical shift does not match literature

values.

Figure S.78 Stacked 1H NMR spectra of the reaction between Ph2SiH2 and iPrNH2 catalyzed by 1

Figure S.79 1H NMR spectrum of the reaction between Ph2SiH2 and iPrNH2 catalyzed by 1

Figure S.80 1H-29Si{1H} HSQC spectra of the reaction between Ph2SiH2 and iPrNH2 catalyzed

Ph2SiH2 and Et2NH.14 An oven-dried scintillation vial containing 1 (3.6 mg, 8.5 mol %) was

charged with Ph2SiH2 (22.7 mg, 0.1 mmol) followed by 0.5 mL benzene-d6, Et2NH (47.5 mg, 0.7

mmol), and TMS (6.5 mg, 61.4 mol %). After 24 h of irradiation, the reaction showed 22%

conversion to Ph2SiH(NEt2) according to 1H NMR spectroscopy.

Figure S.81 Stacked 1H NMR spectra of the reaction between Ph2SiH2 and Et2NH catalyzed by 1

Figure S.82 1H NMR spectrum of the reaction between Ph2SiH2 and Et2NH catalyzed by 1

Figure S.83 1H-29Si{1H} HSQC spectra of the reaction between Ph2SiH2 and Et2NH catalyzed by

References

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