Cyclopentadiene with two coordinating sites: 1,5-bis(diphenylphosphino) -2,3,4-trimethylcyclopenta-1,3-diene

Article abstract of DOI:10.1016/S0022-328X(96)06773-3

The possibility of obtaining the new bidentate 1,2-diphenylphosphinocyclopentadienyl ligand has been studied. 1,5-bis(diphenylphosphino)-2,3,4-trimethylcyclopenta-1,3-diene can be formed from butanone and chlorodiphenylphosphine in eight steps. The results of chemical and spectroscopic studies reveal that a 1,5-sigmatropic migration of the diphenylphosphino group takes place: the 1,2-diphenylphosphino-substituted species are converted into 1,3 species.