Diastereoselective Synthesis of Chiral 2,3-Disubstituted Indolines via Formal [3+2]-Cycloaddition of Arynes with γ-Amino-α,β-unsaturated Esters

Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles

A convenient and efficient method for the synthesis of optically active difluoro-substituted indoline derivatives starting from the corresponding 3H-indoles by chiral phosphoric acid-catalyzed transfer hydrogenation was developed. Using Hantzsch ester as the hydrogen source under mild reaction conditions, the target products can be obtained with excellent yield and enantioselectivity.