Synthesis and Catalytic Properties of Di- and Trinuclear Palladium Complexes with PCP-Pincer Ligands
摘要:
Linear and branched conjugated pincer ligands having Ph(2)p groups were synthesized: 3,3'5,5- tetrakis(diphenylphosphinomethyl)diphenylacetylene, 3,3',5,5'-tetrakis(diphenylphosphinomethyl)diphenyldiacetylene, 1,3,5-tris[3,5-bis(diphenylphosphinomethyl)phenylethynyl]benzene, and hexakis[3,5-bis(diphenylphosphinomethyl)phenylethynyl]benzene. Palladation of these ligands by heating with Pd(BF4)(2)(MeCN)(4) in boiling acetonitrile gave the corresponding di- and trinuclear ionic pincer palladium complexes. No individual complex was obtained from hexakis [3,5 -bis(diphenylphosphinomethyl)phenylethynyl] benzene. The ionic complexes were converted into the corresponding chloride complexes by treatment with sodium chloride in a mixture of water with methylene chloride. The structure of the ionic palladium complex with 3,3%5,5 -tetrakis(diphenylphosphinomethyl)diphenylacetylene was established by X-ray analysis. The obtained palladium complexes exhibited a considerable catalytic activity in the Heck reaction of iodobenzene with ethyl acrylate and in the Michael addition of ethyl cyanoacetate with methyl vinyl ketone. The catalytic activity per palladium atom decreases as the number of palladium atoms in the complex increases.
Synthesis and Catalytic Properties of Di- and Trinuclear Palladium Complexes with PCP-Pincer Ligands
摘要:
Linear and branched conjugated pincer ligands having Ph(2)p groups were synthesized: 3,3'5,5- tetrakis(diphenylphosphinomethyl)diphenylacetylene, 3,3',5,5'-tetrakis(diphenylphosphinomethyl)diphenyldiacetylene, 1,3,5-tris[3,5-bis(diphenylphosphinomethyl)phenylethynyl]benzene, and hexakis[3,5-bis(diphenylphosphinomethyl)phenylethynyl]benzene. Palladation of these ligands by heating with Pd(BF4)(2)(MeCN)(4) in boiling acetonitrile gave the corresponding di- and trinuclear ionic pincer palladium complexes. No individual complex was obtained from hexakis [3,5 -bis(diphenylphosphinomethyl)phenylethynyl] benzene. The ionic complexes were converted into the corresponding chloride complexes by treatment with sodium chloride in a mixture of water with methylene chloride. The structure of the ionic palladium complex with 3,3%5,5 -tetrakis(diphenylphosphinomethyl)diphenylacetylene was established by X-ray analysis. The obtained palladium complexes exhibited a considerable catalytic activity in the Heck reaction of iodobenzene with ethyl acrylate and in the Michael addition of ethyl cyanoacetate with methyl vinyl ketone. The catalytic activity per palladium atom decreases as the number of palladium atoms in the complex increases.
Acetylene-bridged P,C,P′-ligands and corresponding cyclopalladated compounds
作者:Irina P Beletskaya、Alexey V Chuchurjukin、Harm P Dijkstra、Gerard P.M van Klink、Gerard van Koten
DOI:10.1016/s0040-4039(99)02181-4
日期:2000.2
Bis-'pincer'-cyclopalladates 1 and 2 containing an ethynediyl- or a butadiynediyl-bridge have been synthesized, characterized and used as precatalysts in the Heck reaction. (C) 2000 Elsevier Science Ltd. All rights reserved.
Synthesis and Catalytic Properties of Di- and Trinuclear Palladium Complexes with PCP-Pincer Ligands
作者:I. P. Beletskaya、A. V. Chuchuryukin、G. van Koten、H. P. Dijkstra、G. P. M. van Klink、A. N. Kashin、S. E. Nefedov、I. L. Eremenko
DOI:10.1023/b:rujo.0000010214.72250.5a
日期:2003.9
Linear and branched conjugated pincer ligands having Ph(2)p groups were synthesized: 3,3'5,5- tetrakis(diphenylphosphinomethyl)diphenylacetylene, 3,3',5,5'-tetrakis(diphenylphosphinomethyl)diphenyldiacetylene, 1,3,5-tris[3,5-bis(diphenylphosphinomethyl)phenylethynyl]benzene, and hexakis[3,5-bis(diphenylphosphinomethyl)phenylethynyl]benzene. Palladation of these ligands by heating with Pd(BF4)(2)(MeCN)(4) in boiling acetonitrile gave the corresponding di- and trinuclear ionic pincer palladium complexes. No individual complex was obtained from hexakis [3,5 -bis(diphenylphosphinomethyl)phenylethynyl] benzene. The ionic complexes were converted into the corresponding chloride complexes by treatment with sodium chloride in a mixture of water with methylene chloride. The structure of the ionic palladium complex with 3,3%5,5 -tetrakis(diphenylphosphinomethyl)diphenylacetylene was established by X-ray analysis. The obtained palladium complexes exhibited a considerable catalytic activity in the Heck reaction of iodobenzene with ethyl acrylate and in the Michael addition of ethyl cyanoacetate with methyl vinyl ketone. The catalytic activity per palladium atom decreases as the number of palladium atoms in the complex increases.