chapter 8 i. nucleophilic substitution (in depth) ii. competion with elimination

Chapter 8Chapter 8

I. Nucleophilic Substitution (I. Nucleophilic Substitution (in depthin depth))

II. Competion with EliminationII. Competion with Elimination

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Substrate is a sp3 hybridized carbon atom Substrate is a sp3 hybridized carbon atom (cannot be an a vinylic halide or an(cannot be an a vinylic halide or anaryl halide except under special conditions toaryl halide except under special conditions tobe discussed in Chem 227)be discussed in Chem 227)

XX

CCCC

XX

Nucleophilic SubstitutionNucleophilic Substitution

Many nucleophilic substitutions follow aMany nucleophilic substitutions follow a

second-order rate law.second-order rate law.

CHCH33Br + HO Br + HO – – CHCH33OH + Br OH + Br ––

rate = rate = k k [CH[CH33Br] [HO Br] [HO – – ]]

What is the reaction order of each starting material?What is the reaction order of each starting material?

What can you infer on a molecular level?What can you infer on a molecular level?

What is the overall order of reaction?What is the overall order of reaction?

KineticsKinetics

HOHO – – CHCH33BrBr++ HOCHHOCH33 BrBr – –++

one step

concerted

one step

concerted

Bimolecular mechanismBimolecular mechanism

HOHO – – CHCH33BrBr++ HOCHHOCH33 BrBr – –++

one step

concerted

one step

concerted

HOHO CHCH33 BrBr

transition statetransition state

Bimolecular mechanismBimolecular mechanism

Stereochemistry of SStereochemistry of SNN2 Reactions2 Reactions

GeneralizationGeneralization

Nucleophilic substitutions that exhibitsecond-order kinetic behavior are stereospecific and proceed withinversion of configuration.

QuickTime™ and aYUV420 codec decompressor

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nucleophile attacks carbonnucleophile attacks carbonfrom side opposite bondfrom side opposite bondto the leaving groupto the leaving group

Inversion of ConfigurationInversion of Configuration

nucleophile attacks carbonnucleophile attacks carbonfrom side opposite bondfrom side opposite bondto the leaving groupto the leaving group

three-dimensionalthree-dimensionalarrangement of bonds inarrangement of bonds inproduct is opposite to product is opposite to that of reactantthat of reactant

Inversion of ConfigurationInversion of Configuration

Inversion of configuration (Walden inversion) in an SN2 reaction is due to “back side attack”

P.Walden, P.Walden, BerichteBerichte, , 2929(1): 133-138 (1896)(1): 133-138 (1896)

Riga Polytechnical CollegeRiga Polytechnical College

Could there be another mechanism that provides the same Could there be another mechanism that provides the same

results?results?

Roundabout SN2 Mechanism

Traditional SN2 Mechanism

Videos courtesy of William L. Hase, Texas Tech University

http://pubs.acs.org/cen/news/86/i02/8602notw1.html

Physicist Roland Wester and his team in Matthias Weidemüller's group at the University of Freiburg, in Germany, in collaboration with William L. Hase's group at Texas Tech University, provide direct evidence for this mechanism in the gas phase. However, they also detected an additional, unexpected mechanism. In this new pathway, called the roundabout mechanism, chloride bumps into the methyl group and spins the entire methyl iodide molecule 360° before chloride substitution occurs.

The team imaged SN2 reactions at different collision energies, which depend on the speed at which chloride smashes into methyl iodide. Data at lower collision energies support the traditional SN2 mechanism. However, at higher collision energies, about 10% of the iodide ions fell outside of the expected distribution. "We saw a group of iodide ions with a much slower velocity than the rest," says Wester. "Since energy is conserved, if iodide ions are slow, the energy has to be somewhere else."

On the basis of calculations performed by their colleagues at Texas Tech, the team concluded that the energy missing from the iodide transfers to the methyl chloride product in the form of rotational excitation, supporting the proposed roundabout mechanism.

SN2 Reaction Mechanisms: Gas Phase (2008)

Traditional Roundabout

Published by AAAS

J. Mikosch et al., Science 319, 183 -186 (2008)

Fig. 1. Calculated MP2(fc)/ECP/aug-cc-pVDZ Born-Oppenheimer potential energy along the reaction coordinate g = RC-I - RC-Cl for the SN2 reaction Cl- + CH3I and obtained

stationary points

Published by AAAS


Fig. 2. (A to D) Center-of-mass images of the I- reaction product velocity from the reaction of Cl- with CH3I at four different relative collision energies

Published by AAAS


Fig. 3. View of a typical trajectory for the indirect roundabout reaction mechanism at 1.9 eV that proceeds via CH3 rotation

A stereospecific reaction is one in whichA stereospecific reaction is one in whichstereoisomeric starting materials givestereoisomeric starting materials givestereoisomeric products.stereoisomeric products.

The reaction of 2-bromooctane with NaOH The reaction of 2-bromooctane with NaOH (in ethanol-water) is stereospecific.(in ethanol-water) is stereospecific.

(+)-2-Bromooctane (–)-2-Octanol(+)-2-Bromooctane (–)-2-Octanol

(–)-2-Bromooctane (–)-2-Bromooctane (+)-2- (+)-2-OctanolOctanol

Stereospecific ReactionStereospecific Reaction

CC

HH

CHCH33

BrBr

CHCH33(CH(CH22))55

CC

HH

CHCH33

HOHO

(CH(CH22))55CHCH33

NaOHNaOH

(+)-2-Bromooctane(+)-2-Bromooctane (–)-2-Octanol(–)-2-Octanol

Stereospecific ReactionStereospecific Reaction

CC

HH

CHCH33

BrBr

CHCH33(CH(CH22))55

CC

HH

CHCH33

HOHO

(CH(CH22))55CHCH33

NaOHNaOH


QuestionQuestion

The absolute configurations of (+)-2-bromooctane The absolute configurations of (+)-2-bromooctane and (–)-2-octanol are respectively:and (–)-2-octanol are respectively:

A) R- & R- B) S- and S- C) R- & S- D) S- & R-A) R- & R- B) S- and S- C) R- & S- D) S- & R-

CC

HH

CHCH33

BrBr

CHCH33(CH(CH22))55

CC

HH

CHCH33

HOHO

(CH(CH22))55CHCH33

NaOHNaOH


AnswerAnswer

The absolute configurations of (+)-2-bromooctane The absolute configurations of (+)-2-bromooctane and (–)-2-octanol are respectively:and (–)-2-octanol are respectively:

A) R- & R- B) S- and S- C) R- & S- A) R- & R- B) S- and S- C) R- & S- D) S- & R-D) S- & R-

HH BrBr

CHCH33

CHCH22(CH(CH22))44CHCH33

1)1) Draw the Fischer projection formula for (+)-S-2-bromooctane. Draw the Fischer projection formula for (+)-S-2-bromooctane.

2)2) Write the Fischer projection of the Write the Fischer projection of the

(–)-2-octanol formed from it by nucleophilic substitution (–)-2-octanol formed from it by nucleophilic substitution

with inversion of configuration.with inversion of configuration.

HOHO HH

CHCH33

CHCH22(CH(CH22))44CHCH33

R-R-

Question Question

True (A) / False (B)True (A) / False (B)

A racemic mixture of (R- ) and (S- )-2-A racemic mixture of (R- ) and (S- )-2-bromobutane produces an optically active bromobutane produces an optically active product.product.

Answer Answer

True (A) / True (A) / False (B)False (B)

A racemic mixture of (R- ) and (S- )-2-A racemic mixture of (R- ) and (S- )-2-bromobutane produces an optically active bromobutane produces an optically active product.product.

Optically inactive starting materials Optically inactive starting materials produce optically inactive products. The produce optically inactive products. The products in this case are also racemic. products in this case are also racemic. Inversion occurs with both enantiomers.Inversion occurs with both enantiomers.

A conceptual view of SA conceptual view of SNN2 reactions2 reactions

Why does the nucleophile attack from the back side?

Steric Effects in SSteric Effects in SNN2 Reactions2 Reactions

The rate of nucleophilic substitutionThe rate of nucleophilic substitutionby the Sby the SNN2 mechanism is governed2 mechanism is governed

by steric effects.by steric effects.

Crowding at the carbon that bears Crowding at the carbon that bears the leaving group slows the rate ofthe leaving group slows the rate ofbimolecular nucleophilic substitution.bimolecular nucleophilic substitution.

Crowding at the Reaction SiteCrowding at the Reaction Site

RBr + LiI RI + LiBrRBr + LiI RI + LiBr

AlkylAlkyl ClassClass RelativeRelativebromidebromide raterate

CHCH33BrBr MethylMethyl 221,000221,000

CHCH33CHCH22BrBr PrimaryPrimary 1,3501,350

(CH(CH33))22CHBrCHBr SecondarySecondary 11

(CH(CH33))33CBrCBr TertiaryTertiary too smalltoo small

to measureto measure

Reactivity toward substitution by the SReactivity toward substitution by the SNN2 2

mechanismmechanism

A bulky substituent in the alkyl halide reduces thereactivity of the alkyl halide: steric hindrance

CHCH33BrBr

CHCH33CHCH22BrBr

(CH(CH33))22CHBrCHBr

(CH(CH33))33CBrCBr

Decreasing SDecreasing SNN2 Reactivity2 Reactivity

Reaction coordinate diagrams for (a) the SN2 reaction of methyl bromide and (b) an SN2 reaction of a sterically

hindered alkyl bromide

Question Question

Which chloride will react faster with NaI in Which chloride will react faster with NaI in acetone?acetone?

A)A) B) B)

C)C) D) D)

AnswerAnswer

Which chloride will react faster with NaI in Which chloride will react faster with NaI in acetone?acetone?

A)A) B)B)

C)C) D) D)

The rate of nucleophilic substitutionThe rate of nucleophilic substitutionby the Sby the SNN2 mechanism is governed2 mechanism is governed

by steric effects.by steric effects.

Crowding at the carbon adjacentCrowding at the carbon adjacentto the one that bears the leaving groupto the one that bears the leaving groupalso slows the rate of bimolecularalso slows the rate of bimolecularnucleophilic substitution, but the nucleophilic substitution, but the effect is smaller.effect is smaller.

Crowding Adjacent to the Reaction SiteCrowding Adjacent to the Reaction Site

RBr + LiI RI + LiBrRBr + LiI RI + LiBr

AlkylAlkyl StructureStructure RelativeRelativebromidebromide raterate

EthylEthyl CHCH33CHCH22BrBr 1.01.0

PropylPropyl CHCH33CHCH22CHCH22BrBr 0.80.8

IsobutylIsobutyl (CH(CH33))22CHCHCHCH22BrBr 0.0360.036

NeopentylNeopentyl (CH(CH33))33CCHCCH22BrBr 0.000020.00002

Effect of chain branching on rate of SEffect of chain branching on rate of SNN2 2

substitutionsubstitution

Question Question

Which alkyl chloride will react faster with NaI in Which alkyl chloride will react faster with NaI in acetone?acetone?

A) A) B) B)

C)C) D) D)

AnswerAnswer

Which alkyl chloride will react faster with NaI in Which alkyl chloride will react faster with NaI in acetone?acetone?

A) A) B)B)

C)C) D) D)

8.18.1

Functional Group Functional Group

Transformation By Nucleophilic Transformation By Nucleophilic

SubstitutionSubstitution

Y Y ::––

RR XX YY RR++ : : XX––

nucleophilenucleophile is a Lewis base (electron-pair donor) is a Lewis base (electron-pair donor)

often negatively charged and used as often negatively charged and used as NaNa++ or K or K++ salt salt

substrate is usually an substrate is usually an alkylalkyl halide, (most often 1halide, (most often 1oo))

Nucleophilic SubstitutionNucleophilic Substitution

++

The nucleophiles described in Sections 8.1-8.6The nucleophiles described in Sections 8.1-8.6are anions.are anions.

....

....HOHO::–– ....

....CHCH33OO::––....

....HSHS::–– ––

CCNN:: :: NN33

....

....HOHHOH CHCH33OHOH........

NHNH33::

NucleophilesNucleophiles

––

But, all nucleophiles (neutral electron rich molecules)But, all nucleophiles (neutral electron rich molecules) are Lewis bases.are Lewis bases.

++ RR XX

Alkoxide ion as the nucleophileAlkoxide ion as the nucleophile

....OO::

....R'R'

––

Table 8.1 Examples of Nucleophilic SubstitutionTable 8.1 Examples of Nucleophilic Substitution

gives an ethergives an ether

++ : : XXRR....OO....

R'R' ––

++ RR XX

Carboxylate ion as the nucleophile

....OO::

....R'CR'C

––OO

gives an estergives an ester

++ : : XXRR....OO....

R'CR'C ––OO


++ RR XX

Hydrogen sulfide ion as the nucleophileHydrogen sulfide ion as the nucleophile

....SS::

....HH

––

gives a thiolgives a thiol

++ : : XXRR....SS....

HH ––


Question Question

Select the major organic product when (Select the major organic product when (SS)-2-)-2-propanol is reacted with SOClpropanol is reacted with SOCl22 in pyridine in pyridine

followed by the addition of NaSH in ethanol.followed by the addition of NaSH in ethanol.

A) A) B)B)

C)C) D)D)

AnswerAnswer

Select the major organic product when (Select the major organic product when (SS)-2-)-2-propanol is reacted with SOClpropanol is reacted with SOCl22 in pyridine in pyridine

followed by the addition of NaSH in ethanol.followed by the addition of NaSH in ethanol.

A) A) B)B)

C)C) D)D)

Question Question

The best combination of reactants for preparing The best combination of reactants for preparing (CH(CH33))33CSCHCSCH33 is: is:

A)A) (CH(CH33))33CCl + CHCCl + CH33SKSK

B)B) (CH(CH33))33CBr + CHCBr + CH33SNaSNa

C)C) (CH(CH33))33CSK + CHCSK + CH33OHOH

D)D) (CH(CH33))33CSNa + CHCSNa + CH33BrBr

AnswerAnswer

The best combination of reactants for preparing The best combination of reactants for preparing (CH(CH33))33CSCHCSCH33 is: is:

A)A) (CH(CH33))33CCl + CHCCl + CH33SKSK

B)B) (CH(CH33))33CBr + CHCBr + CH33SNaSNa

C)C) (CH(CH33))33CSK + CHCSK + CH33OHOH

D)D) (CH(CH33))33CSNa + CHCSNa + CH33BrBr

++ RR XX

Cyanide ion as the nucleophileCyanide ion as the nucleophile

––CCNN:: ::


gives a nitrilegives a nitrile

++ : : XXRR ––CCNN::

Azide ion as the nucleophileAzide ion as the nucleophile

.... ....––

NN NN NN::::–– ++

++ RR XX


....

gives an alkyl azidegives an alkyl azide

++ : : XXRR ––....NN NN NN::

–– ++

8.28.2Relative Reactivity of Halide Relative Reactivity of Halide

Leaving GroupsLeaving Groups

GeneralizationGeneralization

Reactivity of halide leaving groups in Reactivity of halide leaving groups in nucleophilic substitution is the same as nucleophilic substitution is the same as for elimination.for elimination.

RIRI

RBrRBr

RClRCl

RFRF

most reactivemost reactive

least reactiveleast reactive

BrBrCHCH22CHCH22CHCH22ClCl + Na + NaCNCN

A single organic product was obtained when A single organic product was obtained when 1-bromo-3-chloropropane was allowed to react 1-bromo-3-chloropropane was allowed to react with one molar equivalent of sodium cyanide in with one molar equivalent of sodium cyanide in aqueous ethanol. What was this product?aqueous ethanol. What was this product?

Br is a better leaving Br is a better leaving group than Clgroup than Cl

Problem 8.2Problem 8.2

BrBrCHCH22CHCH22CHCH22ClCl + Na + NaCNCN

A single organic product was obtained when A single organic product was obtained when 1-bromo-3-chloropropane was allowed to react 1-bromo-3-chloropropane was allowed to react with one molar equivalent of sodium cyanide in with one molar equivalent of sodium cyanide in aqueous ethanol. What was this product?aqueous ethanol. What was this product?

Problem 8.2Problem 8.2

CHCH22CHCH22CHCH22ClCl + Na + NaBrBrCCNN::

Question Question

What is the major product of the reaction of the What is the major product of the reaction of the dihalide at the right with 1 equivalent ofdihalide at the right with 1 equivalent of

NaSH in dimethyl sulfoxide? NaSH in dimethyl sulfoxide?

A)A) B)B)

C)C) D)D)

Question 8Question 8

What is the major product of the reaction of the What is the major product of the reaction of the dihalide at the right with 1 equivalent ofdihalide at the right with 1 equivalent of

NaSH in dimethyl sulfoxide? NaSH in dimethyl sulfoxide?

A)A) B)B)

C)C) D)D)

8.128.12Improved Leaving Groups Improved Leaving Groups

Alkyl SulfonatesAlkyl Sulfonates

Leaving GroupsLeaving Groups

We have seen numerous examples of We have seen numerous examples of nucleophilic substitution in which nucleophilic substitution in which XX in R in RXX is a is a halogen.halogen.

Halogen is not the only possible leaving Halogen is not the only possible leaving group, though.group, though.

Other RX CompoundsOther RX Compounds

ROSCHROSCH33

OO

OO

ROSROS

OO

OO

CHCH33

AlkylAlkylmethanesulfonatemethanesulfonate

(mesylate)(mesylate)(triflate = -CF(triflate = -CF3 3 ))

AlkylAlkylpp-toluenesulfonate-toluenesulfonate

(tosylate)(tosylate)

Behave in the same way as alkyl halidesBehave in the same way as alkyl halides

PreparationPreparation

(abbreviated as ROTs)(abbreviated as ROTs)

ROHROH ++

CHCH33 SOSO22ClClpyridinepyridine

ROSROS

OO

OO

CHCH33

Tosylates are prepared by the reaction of Tosylates are prepared by the reaction of alcohols with alcohols with pp-toluenesulfonyl chloride-toluenesulfonyl chloride(usually in the presence of pyridine).(usually in the presence of pyridine).

Tosylates Undergo Typical Nucleophilic Tosylates Undergo Typical Nucleophilic Substitution ReactionsSubstitution Reactions

HH

CHCH22OTsOTs

KCNKCN

ethanol-ethanol-waterwater

HH

CHCH22CNCN

(86%)(86%)

The best leaving groups are weakly basic.The best leaving groups are weakly basic.

Table 8.8Table 8.8Approximate Relative Reactivity of Leaving GroupsApproximate Relative Reactivity of Leaving Groups

Leaving Leaving Relative Relative Conjugate acidConjugate acid ppKKaa of of

Group Group RateRate of leaving group of leaving group conj. acidconj. acid

FF–– 1010-5-5 HFHF 3.53.5

ClCl–– 11 HClHCl -7-7

BrBr–– 1010 HBrHBr -9-9

II–– 101022 HIHI -10-10

HH22OO 101011 H H33OO++ -1.7-1.7

TsOTsO–– 101055 TsOH TsOH -2.8-2.8CFCF33SOSO22OO–– 10108 8 CFCF33SOSO22OHOH -6 -6

Table 8.8Table 8.8Approximate Relative Reactivity of Leaving GroupsApproximate Relative Reactivity of Leaving Groups

Leaving Leaving Relative Relative Conjugate acidConjugate acid ppKKaa of of

Group Group RateRate of leaving group of leaving group conj. acidconj. acid

FF–– 1010-5-5 HFHF 3.53.5

ClCl–– 11 HClHCl -7-7

BrBr–– 1010 HBrHBr -9-9

II–– 101022 HIHI -10-10

HH22OO 101011 H H33OO++ -1.7-1.7

TsOTsO–– 101055 TsOH TsOH -2.8-2.8CFCF33SOSO22OO–– 10108 8 CFCF33SOSO22OHOH -6 -6

Sulfonate esters are extremely good leaving groups; sulfonate ions are very weak bases.

Tosylates can be Converted to Alkyl Tosylates can be Converted to Alkyl HalidesHalides

NaNaBrBr

DMSODMSO

(82%)(82%)

OTsOTs

CHCH33CHCHCHCH22CHCH33

BrBr

CHCH33CHCHCHCH22CHCH33

Tosylate is a better leaving group than bromide.Tosylate is a better leaving group than bromide.

Tosylates Allow Control of StereochemistryTosylates Allow Control of Stereochemistry

Preparation of tosylate does not affect any of the Preparation of tosylate does not affect any of the bonds to the chirality center, so configuration and bonds to the chirality center, so configuration and optical purity of tosylate is the same as the optical purity of tosylate is the same as the alcohol from which it was formed.alcohol from which it was formed.

CC

HH

HH33CC

OOHH

CHCH33(CH(CH22))55 TsClTsCl

pyridinepyridine

CC

HH

HH33CC

OOTsTs

CHCH33(CH(CH22))55

Having a tosylate of known optical purity and Having a tosylate of known optical purity and absolute configuration then allows the absolute configuration then allows the preparation of other compounds of known preparation of other compounds of known configuration by Sconfiguration by SNN2 processes.2 processes.

NuNu––

SSNN22

CC

HH

HH33CC

OOTsTs

CHCH33(CH(CH22))55

CC

HH

CHCH33

(CH(CH22))55CHCH33

NuNu

Tosylates Allow Control of StereochemistryTosylates Allow Control of Stereochemistry

Nucleophiles and NucleophilicityNucleophiles and Nucleophilicity

RankRank NucleophileNucleophile RelativeRelativerate rate

strongstrong II--, HS, HS--, RS, RS-- >10>1055

good good BrBr--, HO, HO--, , 101044

RORO--, CN, CN--, N, N33--

fairfair NHNH33, Cl, Cl--, F, F--, RCO, RCO22-- 101033

weakweak HH22O, ROHO, ROH 11

very weakvery weak RCORCO22HH 1010-2-2

Table 8.4 NucleophilicityTable 8.4 Nucleophilicity

RankRank NucleophileNucleophile RelativeRelativerate rate

good good HOHO––, RO, RO–– 101044

fairfair RCORCO22–– 101033

weakweak HH22O, ROHO, ROH 11

When the attacking atom is the same (oxygenWhen the attacking atom is the same (oxygenin this case), nucleophilicity increases with in this case), nucleophilicity increases with increasing basicity.increasing basicity.

Table 8.4 NucleophilicityTable 8.4 Nucleophilicity

Nucleophiles and NucleophilicityNucleophiles and NucleophilicitySSNN1 vs. S1 vs. SNN22

....

....HOHHOH CHCH33OH and EtOHOH and EtOH........

for examplefor example

Many of the protic solvents in which Many of the protic solvents in which nucleophilic substitutions can be carried out nucleophilic substitutions can be carried out are themselves nucleophiles.are themselves nucleophiles.

NucleophilesNucleophiles

The term The term solvolysis solvolysis refers to a nucleophilicrefers to a nucleophilicsubstitution in which the nucleophile is the solvent.substitution in which the nucleophile is the solvent.

SolvolysisSolvolysis

SSNN2 Reactions are favored in2 Reactions are favored in

Polar Aprotic Non-nucleophilic SolventsPolar Aprotic Non-nucleophilic Solvents

An aprotic solvent is one that doesAn aprotic solvent is one that doesnot have an —OH group.not have an —OH group.

SSNN1 Reactions are favored in1 Reactions are favored in

Polar Protic SolventsPolar Protic Solvents

Substitution by an anionic nucleophile: Substitution by an anionic nucleophile: SSNN2 kinetics2 kinetics

R—R—XX + + ::NuNu—— R—Nu + R—Nu + ::XX——

++

Solvolysis: Solvolysis: SSNN1 kinetics1 kinetics

R—R—XX + + ::Nu—HNu—H RR—Nu—H —Nu—H + + ::XX——


Carbocation Carbocation

intemediate intemediate 2nd 2nd intermediateintermediate

++

Substitution by an anionic nucleophile in an aprotic Substitution by an anionic nucleophile in an aprotic non-nucleophilic solvent non-nucleophilic solvent SSNN2 kinetics2 kinetics

R—R—XX + + ::NuNu—— R—Nu + R—Nu + ::XX——

Solvolysis (protic solvents) : Solvolysis (protic solvents) : SSNN1 kinetics1 kinetics

R—R—XX + + ::Nu—HNu—H RR—Nu—H —Nu—H + + ::XX——

RR—Nu —Nu + + HHXXproducts of overall reactionproducts of overall reaction


R—R—XX

Methanolysis is a nucleophilic substitution in Methanolysis is a nucleophilic substitution in which methanol acts as both the solvent andwhich methanol acts as both the solvent andthe nucleophile.the nucleophile.

HH

OO

CHCH33

:: ::++

HH

OO

CHCH33

::RR++ ––HH++

The product is a The product is a methyl ether.methyl ether.

OO::

CHCH33

RR ....

Example: MethanolysisExample: Methanolysis

solventsolvent product from RXproduct from RX

water (HOH)water (HOH) ROHROHmethanol (CHmethanol (CH33OH)OH) ROCHROCH33

ethanol (CHethanol (CH33CHCH22OH)OH) ROCHROCH22CHCH33

formic acid (HCOH)formic acid (HCOH)

acetic acid (CHacetic acid (CH33COH)COH) ROCCHROCCH33

OO

ROCHROCH

OOOO

OO

Some typical solvents in solvolysisSome typical solvents in solvolysis

QuestionQuestion

Which of the following is not a good nucleophile Which of the following is not a good nucleophile in an Sin an SNN1 solvolysis reaction?1 solvolysis reaction?

A)A) NaOCHNaOCH33

B)B) CHCH33OHOH

C)C) CHCH33CHCH22OHOH

D)D) HH22OO

AnswerAnswer

Which of the following is not a good nucleophile Which of the following is not a good nucleophile in an Sin an SNN1 solvolysis reaction?1 solvolysis reaction?

A)A) NaOCHNaOCH33

B)B) CHCH33OHOH

C)C) CHCH33CHCH22OHOH

D)D) HH22OO

chapter 8 i. nucleophilic substitution (in depth) ii. competion with elimination

Documents

reaction order

reaction mechanisms

overall order of reaction

group of iodide ions

methyl group

roundabout mechanism

i reaction product velocity

methyl chloride product