ИСТИНА

The novel manganese benzylphosphoniocarbene [Mn]=C(+PPh2Me)–CH2Ph]BF4 (1) and diphenylvinylphosphoniocarbene complexes [Mn]=C(+PR3)–CH=CPh2]BF4 (2a-d) (hereinafter, Mn = Cp(CO)2Mn) were prepared by the reaction of benzyl- [Mn]+C—CH2Ph]BF4 and diphenylvinylcarbyne complexes [Mn]+C—CH=CPh2]BF4 with tertiary phosphines and found to rearrange in solutions (THF, acetone, or CH2Cl2) to the corresponding phosphoniostyrene [Mn]{η2-HC(+PPh2Me)=CHPh}BF4 (5) and phosphoniodiphenylallene complexes [Mn]{η2-HC(+PR3)=C=CPh2}BF4 (6a-d). The careful IR spectral monitoring shows that, in all cases, the rearrangement is a two-step process: 1) deprotonation to the intermediate phosphoniostyryl [Mn]–—C(+PPh2Me)=CHPh (3) and phosphonioallenyl adducts [Mn]–—C(+PR3)=C=CPh2 (4a-d) and 2) protonation of the latter to form olefin 5 and allenes 6a-d.