Cu-Mediated Sulfonyl Radical-Enabled 5-exo-trig Cyclization of Alkenyl Aldehydes: Access to Sulfonylmethyl 1H-Indenes

摘要

An efficient method for the construction of sulfonylmethyl 1H -indenes via Cu(I)-mediated sulfonyl radical-enabled 5-exo-trig cyclization of alkenyl aldehydes has been developed for the first time. Mechanistic studies indicated that a radical addition–cyclization–elimination (RACE) process might be involved. The reaction features a relatively broad substrate scope, good annulation efficiency, and varying functional group tolerance.