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

A one step formal [3+2]-annulation protocol for the synthesis of 2,3-disubstituted indolines is described. The in situ generated aryne acts as a two-atom component, and γ-amino-α,β-unsaturated esters acting as a three-atom component to construct indoline units in a highly regio- and diastereoselective manner with yields ranging from 63 to 80%.