Enantioselective conjugate addition of diethylzinc to vinylogous imines generated in situ from sulfonyl indoles

Abstract

Enantioselective conjugate addition of diethyl zinc to vinylogous imines generated in situ from sulfonyl indoles was developed. Various sulfonyl indoles reacted with diethyl zinc in the presence of chiral phosphoramidites in combination with copper triflate affording the corresponding indole substituted alkanes in up to 99% yield with moderate to good enanti-oselectivity (up to 80% ee).