Thermal migration of an ethynyl group from one benzene ring to another by reversible vinylidene C-H insertion

Article abstract of DOI:10.1016/S0040-4039(97)00225-6

Evidence is presented for the high temperature opening of a 5-membered ring by extrusion of a carbene (the reverse of a C-H bond insertion), which results in the net thermal migration of an ethynyl group from one benzene ring to another.