Reaction of the RuTp(PR 3)Cl fragment with alkynols: Formation of carbene, vinylidene, allenylidene, and carbyne complexes

Abstract

The reaction of RuTp(COD)Cl ( 1) with PR 3 (PR 3 = PPh 2 i Pr, P i Pr 3, PPh 3) and propargylic alcohols HC CCPh 2OH, HC CCFc 2OH (Fc = ferrocenyl), and HC CC(Ph)MeOH has been studied.In the case of PR 3 = PPh 2 i Pr, P i Pr 3 and HC CCPh 2OH, the 3-hydroxyvinylidene complexes RuTp(PPh 2 i Pr)( C CHC(Ph) 2OH)Cl ( 2a) and RuTp(P i Pr 3)( C CHC(Ph 2)OH)Cl ( 2b) were isolated.With PR 3 = PPh 2 i Pr and HC CCFc 2OH as well as with PR 3 = PPh 3 and HC CCPh 2OH dehydration takes place affording the allenylidene complexes RuTp(PPh 2 i Pr)( C C CFc 2)Cl ( 3b) and RuTp(PPh 3)( C C CPh 2)Cl ( 3c).Similarly, with PPh 2 i Pr and HC CC(Ph)MeOH rapid elimination of water results in the formation of the vinylvinylidene complex RuTp(PPh 2 i Pr)( C CHC(Ph) CH 2)Cl ( 4).In contrast to the reactions of the RuTp(PR 3)Cl fragment with propargylic alcohols, with HC C(CH 2) n OH ( n = 2, 3, 4, 5) six-, and seven-membered cyclic oxycarbene complexes RuTp(PR 3)( C 4H 6O)Cl ( 5), RuTp(PR 3)( C 5H 8O)Cl ( 6), and RuTp(PR 3)( C 6H 10O)Cl ( 7) are obtained. On the other hand, with 1-ethynylcyclohexanol the vinylvinylidene complex RuTp(PPh 2 i Pr)( C CHC 6H 9)Cl ( 8) is formed. The reaction of the allenylidene complexes 3a– c with acid has been investigated. Addition of CF 3COOH to a solution of 3a– c resulted in the reversible formation of the novel RuTp vinylcarbyne complexes [RuTp(PPh 2 i Pr)( C–CH CPh 2)Cl] + ( 9a), [RuTp(PPh 2 i Pr)( C–CH CFc 2)Cl] + ( 9b), and [RuTp(PPh 3)( C–CH CPh 2)Cl] + ( 9c). The structures of 3a, 3b, and 5b have been determined by X-ray crystallography.