An unprecedented CC double bond cleavage of cyclopropenone and dioxygen activation by multiyne cascade coupling has been developed. This chemistry provides a novel, simple, and efficient approach to synthesize fully substituted conjugate benzofuran derivatives from simple substrates under mild conditions. The density functional theory (DFT) calculations reveal that the unique homolytic cleavages of cyclopropenone and molecular oxygen are crucial to the success of this reaction.

A method for the intermolecular annulation of benzynes with allenes is disclosed.

Csp2–O/Csp2–S difunctionalization of fused highly substituted benzene derivatives was conducted via the multicomponent coupling reaction of tetraynes, sulfoxides, and cyclopropenones. This reaction is associated with several bond cleavage and formation...

The HDDA-derived benzyne intermediate was captured by oxazolines based on the addition reaction of benzyne to the CN double bond. Benzoxazepine derivatives, fused benzoxazepine derivatives, and fully substituted indoles are synthesized in one step. The reaction does not require any catalyst or additives. Possible reaction mechanisms are presented.