Y(OTf)₃‐CuI Catalyzed N‐α Alkynylation of Cyclic Imines with Alkynes

Abstract

An efficient approach to (2R,3S)‐3‐siloxy‐2‐phenylethynyl substituted pyrrolidines was developed through Y(OTf)3‐CuI catalyzed N‐α alkynylation of cyclic imines (1 a and 1 e) with alkynes 2 a–s. As a result, a number of trans‐2‐phenyl acetylene substituted‐3‐siloxy pyrrolidine derivatives 4 aa–as, 4 ea–ef and 4 es were synthesized in moderate to good yields with excellent diastereoselectivities (dr up to 99 : 1).