Dibenzo[b,e]phosphindolizines synthesized by a ring-closing metathesis of benzo[b]phospholes with two vinyl tethers

Dibenzo[b,e]phosphindolizines 1 were successfully synthesized by a ring-closing metathesis of benzo[b]phosphole chalcogenides 2a–2c with two vinyl tethers (for chalcogen analogs 1a–1c), and by a deselenization reaction (for lone-pair analog 1d). The structures, properties, and bowl inversion derived from a phosphorus atom were fully investigated.