Catalytic Asymmetric Disulfuration by a Chiral Bulky Three-Component Lewis Acid-Base

摘要

A three-component Lewis acid-base (Lewis trio) involving a bulky chiral primary amine, B(C6F5)(3) and a bulky tertiary amine has been developed as an effective enamine catalyst for enantioselective disulfuration reactions. The bulky tertiary amine was found to activate a bulky primary-tertiary diamine-borane Lewis pair for enamine catalysis via frustrated interaction. The resulted chiral bulky Lewis trio (BLT) allows for the construction of chiral disulfides via direct disulfuration with beta-ketocarbonyls or alpha-branched aldehydes in a practical and highly stereocontrolled manner.