Migratory insertion reaction of a phosphenium ligand into Mo [sbnd] and W [sbnd]alkyl bonds

Abstract

Treatment of Cp(CO) 2 MeM{P N(Me)CH 2 CH 2 ⎴ X ( OR ) } (M = Mo, W; X = NMe, O) with BF 3 · OEt 2 and then with PPh 3 yields t r a n s -[Cp(CO) 2 (PPh 3 )M{P N(Me)CH 2 CH 2 ⎴ X ( Me ) } ] BF 4 . Reaction of Cp(CO) 2MeMP(OMe) 3 (M = Mo, W) with BF 3 · OEt 2 and then with PPh 3 gives a mixture of [Cp(CO) 2(PPh 3)MP(OMe) 2Me]BF 4 and [Cp(CO) 2(PPh 3)MP(OMe) 3]BF 4. These reactions reveal that migratory insertion of a phosphenium ligand into an M alkyl bond (M = Mo, W) takes place. The structures of t r a n s -[Cp(CO) 2 (PPh 3 )Mo{P N(Me)CH 2 CH 2 ⎴ NMe ( Me ) } ] OTf and [Cp(CO) 2(PPh 3)WP(OMe) 3]BF 4 were determined by single crystal X-ray diffraction studies.