Catalytic Asymmetric Cyanation of Alkylideneindolenines Generated from Sulfonylalkylindoles

The catalytic asymmetric phase-transfer cyanation of alkylideneindolenines, generated in situ from sulfonylalkylindoles, was developed. In the presence of sodium cyanide and a catalytic amount of chiral 1,2,3-triazolium salt, a series of sulfonylalkylindoles can be transformed into the corresponding chiral 3-sec-alkylindoles with good-to-high levels of efficiency and enantioselectivity.