Application of phosphonyl carbanions to highly regioselective synthesis of some diazaphospholes and pyrazolinyl phosphonates

Abstract A series of substituted spiro[3′]pyrazolinylphosphonates and spiro[3]diazaphospholes were synthesized via 1:3-dipolar cycloaddition reaction of 2-diazonio-1,3-dioxo-2,3-dihydro-1 H -inden-2-ide with phosphonyl carbanions: diethyl-cyanomethylphosphonate, -phosphono-acetates, and -vinylphosphonate. On the other hand, treatment of the diazo substrate with diethyl (thiomethyl)methylphosphonate led to the formation of condensed oxadiazine and spiro[3]diazaphosphole. Some compounds were found to possess antibacterial and antifungal activities.