Highly Enantioselective Fluorination of Unprotected 3-Substituted Oxindoles: One-Step Synthesis of BMS 204352 (MaxiPost).

The catalytic enantioselective fluorination of N--H-free 3-substituted oxindoles was accomplished by a Sc(III)/N,N'-dioxide complex. Under mild reaction conditions, a series of 3-aryl- and 3-alkyl-3-fluoro-2-oxin doles were obtained in excellent yields (up to 9896) and enantioselectivities (up to 99% ee) by using N-fluorobisbenzenesulfonimide (NFSI) as the fluorination agent MaxiPost was synthesized efficiently in 81% yield with 96% ee. [ABSTRACT FROM AUTHOR]