A highly efficient method for the construction of cyclopropane-containing dihydroindole derivatives from indolemethylenecyclopropanes with DIAD and DEAD.

A highly efficient method for the construction of cyclopropane-containing dihydroindole derivatives from indolemethylenecyclopropanes with DIAD and DEAD has been disclosed. The transformation could occur under catalyst-free conditions at ambient temperature to afford dihyroindole derivatives in good yields. It has been proved that the strained moiety of methylenecyclopropane in the substrate of indolemethylenecyclopropane is critical and DFT calculations reveal that the reaction proceeds through a two-step pathway.

A facile method for the synthesis of dihydroquinoline-azide from the Lewis acid-catalyzed reaction of alkylidenecyclopropanes with TMSN3.

A facile synthetic method for the formation of dihydroquinoline-azide from alkylidenecyclopropanes and TMSN3 under the catalysis of a Lewis acid has been developed, and a number of azide-containing compounds can be instantly accessed in moderate to good yields. A click reaction with these azido compounds was also realized along with a mechanistic investigation.