Enantioselective Conjugate Silyl Additions to alpha,beta-Unsaturated Aldehydes Catalyzed by Combination of Transition Metal and Chiral Amine Catalysts

• We report that transition metal-catalyzed nucleophilic activation can be combined with chiral amine-catalyzed iminium activation as exemplified by the unprecedented enantioselective conjugate addition of a dimethylsilanyl group to alpha,beta-unsaturated aldehydes. These reactions proceed with excellent 1,4-selectivity to afford the corresponding beta-silyl aldehyde products 3 in high yields and up to 97:3 er using inexpensive bench stable copper salts and simple chiral amine catalysts. The reaction can also generate a quaternary stereocenter with good enantioselectivity. Density functional calculations are performed to elucidate the reaction mechanism and the origin of enantioselectivity.

Ämnesord

NATURVETENSKAP  -- Kemi -- Organisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Organic Chemistry (hsv//eng)

Nyckelord

asymmetric catalysis; organocatalysis; beta-silyl aldehydes; transition metal catalysis; alpha

beta-unsaturated aldehydes

Organic chemistry

Organisk kemi

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