Study of Insertion of Olefins and/or Carbon Monoxide into Phosphine-Imine Palladium Methyl Complexes

摘要

Palladium methyl complexes with a phosphine-imine (P",N) bidentate ligand. [Pd(P"'N)- MeCl] (1), [Pd(P",N)Me(CH3CN)](BF 4) (2), and [Pd(P",N)Me(PPh3)](BF 4) (3), are treated with CO to result in the corresponding Pd-acyl complexes 4-6. NMR studies indicate the formation of a sole isomer with the acyl group cis to the phosphine donor. The neutral complex 4 and the triphenylphosphine-substituted complex 6 cannot serve for the insertion of ethylene. However, the acetoIiitrile complex 5 appears to be active in the insertion reaction with various alkenes as well as ethylene/CO (E-CO) co-oligomerization, resulting in the products 7-14 and 16, which have been isolated and characterized by spectroscopic methods. X-ray structures of 1,2,3,4,7, 10, 11, and 13 are revealed.