gold(i)-catalyzed highly diastereocatalyzed highly diastereo- and … · 2020. 8. 28. · synthesis...

Literature Report (5)

Gold(I)-Catalyzed Highly Diastereo- and EnantioselectiveGold(I) Catalyzed Highly Diastereo and Enantioselective Alkyne Oxidation/Cyclopropanation of 1,6-Enynes

Reporter: Yue JiChecker: Zhang-Pei ChenChecker: Zhang Pei ChenDate: 2015/01/20

Zhang, J. et al.Zhang, J. et al. Angew. Chem. Int. Ed. 2014, 53, 13751.

Content

Introdunction Introdunction

Alkyne Oxidation/Cyclopropannation of 1,6-Enyne

C l i f A S b i d Di Cyclopropannation of Acceptor-Substituted Diazoacetates

Summary

Introduction

Introduction

Intramolecular Asymmetric Cyclopropanation

Asymmetric Alkyne Oxidation/Cyclopropannation of 1,6-Enyne

Entry G t/h Conv. (%) e.r.

1 H 12 >95 51:491 H 12 >95 51:49

2 4-MeOC6H4 5 >95 57:43

3 3,5-Me2C6H3 10 >95 68:32

4 3,5-tBu2C6H3 12 >95 72:28

5 3,5-Ph2C6H3 12 >95 75:25

6 3,5-(CF3)2C6H3 12 >95 85:15

7 9-anthracenyl 12 >95 53:47

8 SiPh 24 85 63:378 SiPh3 24 85 63:37

Zhang, J. et al. Angew. Chem. Int. Ed. 2014, 53, 13751.


Entry AgY Solvent T/oC t/h Yield (%) e.r.

1 AgNTf2 DCE 25 12 >95 85:15g 2

2 AgNTf2 DCM 25 22 72 88:12

3 AgNTf2 THF 25 12 no reaction --

4 AgNTf2 DMSO 25 12 no reaction --

5 AgSbF6 DCM 25 10 >95 88:12

6 A ClO DCM 25 48 52 88 126 AgClO4 DCM 25 48 52 88:12

7 AgSbF6 DCM 0 23 >95 89:11

8 AgSbF6 DCM -15 96 83 92:8g 6

9a AgSbF6 DCM -15 96 85 93:7

a. 4Å MS


R1R1

O

O[(S,S,S)-L9AuCl] (5 mol%)

AgSbF6 (5 mol%)

G

OPh

O

N

OH

OAgSbF6 (5 mol%)

DCM+

1 2 (1.8 eq.) 3

RG

O

P N

Ph

G = 3 5 (CF ) C HG = 3,5-(CF3)2C6H3

Entry R1, 1 R T/oC t/h Yield (%) e.r.

1 Ph,1a H 25 70 30 90:10

2 Ph,1a Me 25 10 91 88:12

3 Ph 1a iPr 25 18 90 84:163 Ph,1a iPr 25 18 90 84:16

4 Ph,1a Me 0 23 91 89:11

5 Ph,1a Me -15 96 85 93:7

6 4-FC6H4,1b Me -15 96 55 91:9

7 4-MeC6H4,1c Me -15 96 86 94:6

8 4-MeOC6H4,1d Me -15 10 92 97:3


ACP of Olefins: Mechanism


ACP of Olefins: Control Experiments


Transformation


[LAuCl] (5 mol%)NaBARF (10 mol%)+

O

P ArAr

Mor-DalPhos

N

O HCO2EtH

1 2a (1.5 eq.) 3

N Au

O

R

YYn

chiralpocket

CO2Et

t/c > 20:1

PAd2PAd2 PAd2PAd2

N

PAd2

TBSOOTBS

N

PAd2

OTBS

N

PAd2

TIPSOOTIPS

N

PAd2

TESOOTESTBSO

L1% %

L2 L3% %

L4% %78%, 63% ee RT, 78%, 86% ee

0 oC, 70%, 90% ee-20 oC, 68%, 94% ee

74%, 85% ee 73%, 52% ee

O

N

PAd2

TBSOOH

N

PPh2

TBSOOTBS

O

O

O PAr2

PAr2O O

PPh2 Ph2P

L556%, 73% ee

L678%, 3% ee

L7NR

L8Mixture

PPh2 Ph2P

R = DTBM-SegPhosZhang, L. et al. Angew. Chem. Int. Ed. 2015, 54, 1245.

Cyclopropannation of Acceptor-Substituted Diazoacetates

ONC

OPh

[Co(D2-Por*)] (2 mol%)

DCM, 24 h, RT

**

ONC

1a 2a

OO

NC N2

1a 2a

NHO

H

N H

O

H(S) (S)

NHO

H

N H

O

Ph

H(R) (R)

Ph(R)(R)

N

N N

N

N

N

H

O

N

N H

HO

CoN

N N

N

NH

O

N

N H

HO

Co

O

H(S)

(S)

O

HPh

Ph

H(R)

(R)

Co(P1) Co(P2)

(R)

(R)

99% yield, 99% de, 55% ee 99% yield, 99% de, -96% ee

Zhang, X. P. et al. J. Am. Chem. Soc. 2011, 133, 15292.


OXPh

X N

O

[Co(P2)] (2 mol%)DCM, 24 h, RT

1a 2a

OO

X N2

O O O

ONC OO2N OMeOC

O O O

99% yieldt/c: >99:1, 96% ee

95% yieldt/c: >99:1, 96% ee

62% yieldt/c: >99:1, 99% ee

OEtO2C OH OMe

99% yieldt/c: >99:1, 90% ee

95% yieldt/c: >99:1, 99% ee

82% yieldt/c: >99:1, 73% ee


1 O

[Co(P2)] (2 mol%)

DCM, 24 h, RTR1

ONC

1 2H

O

R1

O

NC N2

O

1a 2a

ONC

O

ONC

O

ONC

O

ONC

O

ONC

O

O

99% yieldt/c: >99:1 96% ee

99% yieldt/c: >99:1, 98% ee

88% yieldt/c: >99:1 97% ee

99% yieldt/c: >99:1 95% ee

51% yieldt/c: >99:1 92% ee

F3CO

t/c: >99:1, 96% ee t/c: 99:1, 98% ee t/c: >99:1, 97% ee t/c: >99:1, 95% ee t/c: >99:1, 92% ee

ONC

O

ONC

O

ONC

O

ONC

O

ONC

O

93% yieldt/c: >99:1, 91% ee

BocN

93% yieldt/c: 90/10, 91% ee

88% yieldt/c: >99:1, 83% ee

99% yieldt/c: >99:1, 78% ee

99% yieldt/c: 36/64,

69% ee; 23% ee

Summary

1. Alkyne Oxidation/Cyclopropannation of 1,6-Enyne

R1R1

O

O[(S,S,S)-L9AuCl] (5 mol%)

AgSbF6 (5 mol%)+

R2G

P

O

N

Ph

R2

O X

N

OX H

DCM, -15 oC+

G

OPh

G = 3,5-(CF3)2C6H3

Zhang, J. et al. Angew. Chem. Int. Ed. 2014, 53, 13751.

[LAuCl] (5 mol%)NaBARF (10 mol%)+

O

P ArAr

Mor-DalPhos

N

O HCO2EtH

3

N Au

O

R

YYn

chiralpocket

OEt

O

Zhang, L. et al. Angew. Chem. Int. Ed. 2015, 54, 1245.

Summary

2. Intramolecular Cyclopropannation of Acceptor-Substituted Diazoacetates

Zhang, X. P. et al. J. Am. Chem. Soc. 2011, 133, 15292.

Asymmetric cyclopropanation (ACP) of olefins with metallo-carbenes serves as a bedrock for synthetic chemistry. In thiscontext the intramolecular ACP reaction of linear unsaturatedcontext, the intramolecular ACP reaction of linear unsaturateddiazo precursors for the stereoselective construction of[n.1.0]bicyclic ring systems has recently attracted renewedattention owing to its fundamental scientific interest and dauntingattention owing to its fundamental scientific interest and dauntingchallenge. Over the years, remarkable progress has beendescribed in the formation of optically active 3-oxa- and 3-

bi l [3 1 0]h d i tiazabicyclo[3.1.0]hexane derivatives.

More recently, P. Zhang and co-workers successfully developed anMore recently, P. Zhang and co workers successfully developed anintramolecular ACP reaction leading to 3-oxabicyclo[3.1.0]hexanes with diverse substituents by the application of chiralcobalt(II)–porphyrin complexes as metalloradical catalysts Incobalt(II)–porphyrin complexes as metalloradical catalysts. Incontrast, highly catalytic ACP reactions with metal carbenoids forthe synthesis of bicyclo[3.1.0]hexanes, in particular thosecontaining a challenging all carbon quaternary stereocentercontaining a challenging all-carbon quaternary stereocenter,remain comparatively rare, although such enantiomericallyenriched skeletons are tremendously important because of their

id i bi i l d h i lwide occurrence in bioactive natural products, pharmaceuticals,and conformationally restricted biological probes as well as theirversatility in organic synthesis as chiral building blocks. Thus, anew and complementary approach that enables fast access tosuch architectures with multifunctionalized stereocenters is still ingreat demand.g

In summary, we have demonstrated a highly efficient and selectiveIn summary, we have demonstrated a highly efficient and selectivesynthesis of enantiomerically enriched bicyclo[3.1.0]hexan-2-onesthrough gold(I)-catalyzed asymmetric alkyne oxidation/cyclopropanation With the readily available chiral phosphoramiditecyclopropanation. With the readily available chiral phosphoramiditeligand L9, a variety of bicyclo[3.1.0]hexane derivatives containingthree contiguous stereocenters with multiple functionalities wereobtained with up to e r 98:2 under mild conditions Moreover theobtained with up to e.r. 98:2 under mild conditions. Moreover, theefficiency of ynones as safe surrogates of acceptor/acceptor diazoreagents was recognized. Mechanistic studies suggest that the -

ld i l i li i i ib h igold vinyloxyquinolinium species contributes to the enantio-selectivity of the cyclopropanation. This demonstration of gold(I)-catalyzed alkyne oxidation for asymmetric intramolecularcyclopropanation may open the door for the discovery of otherreactions for the enantioselective functionalization of alkynes byoxidation with pyridine/quinoline N-oxides.py q

gold(i)-catalyzed highly diastereocatalyzed highly diastereo- and … · 2020. 8. 28. · synthesis...

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