Enantioselective synthesis of tertiary α-chloro esters by non-covalent catalysis

We report an enantioselective approach to tertiary alpha-chloro esters through the reaction of silyl ketene acetals and N-chlorosuccinimide. The reaction is promoted by a chiral squaramide catalyst, which is proposed to engage both reagents exclusively through non-covalent interactions. Application of the tertiary chloride products in stereospecific substitution reactions is demonstrated. (C) 2015 Elsevier Ltd. All rights reserved.