Intermolecular oxidative decarbonylative [2 + 2 + 2] carbocyclization of N-(2-ethynylaryl)acrylamides with tertiary and secondary alkyl aldehydes involving C(sp3)–H functionalization

A new metal-free oxidative decarbonylative [2 + 2 + 2] carbocyclization of N-(2-ethynylaryl)acrylamides with tertiary and secondary alkyl aldehydes is described. This reaction enables the formation of three new C-C bonds in a single reaction by a sequence of oxidative decarbonylation, radical addition across C-C unsaturated bonds, C-H functionalization and annulation, and represents the first oxidative decarbonylative [2 + 2 + 2] carbocyclization approach using tertiary and secondary alkyl aldehydes as a two carbon unit for assembling six-membered carbocycle-fused polycycles.