Enantioselective Bifunctional Ammonium Salt‐Catalyzed Syntheses of 3‐CF 3 S‐, 3‐RS‐, and 3‐F‐Substituted Isoindolinones

We herein report the ammonium salt‐catalyzed synthesis of chiral 3,3‐disubstituted isoindolinones bearing a heteroatom functionality in the 3‐position. A broad variety of differently substituted CF 3 S‐ and RS‐derivatives were obtained with often high enantioselectivities when using Maruoka's bifunctional chiral ammonium salt catalyst. In addition, a first proof‐of‐concept for the racemic synthesis of the analogous F‐containing products was obtained as well, giving access to one of the rare examples of a fairly stable α‐F‐α‐amino acid derivative.