摘要:
On the basis of the reaction of ethynediylbisphosphonates and chloroethynylphosphonates with classical donor alka-1,3-dienes, a general strategy for synthesis of o-bisphosphanylbenzenes and o-chlorophosphanylbenzenes, which includes two consecutive steps: Diels-Alder condensation -> aromatization of the carbocyclic phosphonate (bisphosphonate) formed -> reduction of the phosphonate groups, was developed. Convenient procedures are devised for aromatization of phosphorus-containing cyclohexa-1,4-dienes and for reduction of o-phenylenebisphosphonates and o-clorophenylphosphonates to primary phosphines. A series of new alkylsubstituted phosphonic chlorides were prepared, and a possibility of functionalization of methyl-substituted o-phenylenebisphosphonates and o-clorophenylphosphonates by the methyl groups is demonstrated.