6927799391

Br

+ RMgBr

CH₂CI₂, -78 °C 0.25 mmol scalę

CuBr₂SMe {5 mol%) (/?,R)-TaniaPhos (6 mol%)

up to 90% ee b/l up to >99:1

X = Me, OMe, OTBS, Br, Cl Substrate scope:

Br

71 % yield 99% ee b/l = 99:1

Cl

69% yield 98% ee b/l > 99:1

b/l = 98:2

b/l >99:1

b/l = 92:8

b/l = 93:7

b/l = 92:8

b/l = 94:6

b/l = 78:22

b/l = 97:3

Scale-upto 1.0 mmol:

Br

Br

n-HexMgBr

CuBr₂SMe (5 mol%) (/?,R)-TaniaPhos (6 mol%)

CH₂CI₂. -78 °C

/>-Hex

76% yield 98% ee b/l = 91:9