Reactions of Cyclopalladated Complexes with Lithium Diphenylphosphide

Reactions of the cyclopalladated dimer {Pd(eta(2)-L-1)(mu-Cl)}(2) (7) derived from N,N-dimethylbenzylamine (HL1) with lithium diphenylphosphide were studied tinder varied conditions. The LiPPh2 reagents used were purchased from Sigma-Aldrich Co. or synthesized from PPh3, ClPPh2, or HPPh2 by known general methods. Depending oil the source of lithium phosphide, solvent, and reagent ratio, reactions of LiPPh2 with complex 7 resulted in the formation of different products. The commercial LiPPh2 solutions reacted with compound 7 and several other cyclopalladated dimeric complexes in THF to form the corresponding mononuclear derivatives with Ph2P(CH2)(4)OH as an auxiliary ligand, Pd(eta(2)-L)Cl{PPh2(CH2)(4)OH}, The monophosphido-bridged analogue of dimer 7, {Pd(eta(2)-L-1)}(2)(mu-Cl)(mu-PPh2) (17), was the most common product of the 1:2 reactions of dimer 7 with other LiPPh2 solutions in THF. ortho-(Diphenylphosphino)-N,N-dimethylbenzylamine (20) was obtained in the reactions of complex 7 with the synthesized solutions of LiPPh2 using a 1:4.5 molar ratio of the reagents in THF or a 1:2 ratio in toluene. Possible mechanisms of these reactions are discussed.