[Copper(I)(Pyridine-Containing Ligand)] Catalyzed Regio- and Steroselective Synthesis of 2-Vinylcyclopropa[b]indolines from 2-Vinylindoles.

A [copper(I)pyridine-containing ligand]-catalyzed reaction between 2-vinylindoles and diazo esters is described. The reaction allows for the synthesis of a series of 2-vinylcyclopropa[b]indolines with excellent levels of regio- and sterocontrol under mild conditions.