Intermediates in the palladium-catalysed reaction of 1,3-dienes Part 8. The reaction of palladium-butadiene complexes with ethyl methylacetoacetate
作者:A. Döhring、R. Goddard、G. Hopp、P.W. Jolly、N. Kokel、C. Krüger
DOI:10.1016/0020-1693(94)03907-0
日期:1994.7
Abstract The catalytic reaction of 1,3-butadiene with ethyl methylacetoacetate in the presence of (η 2 -1,3-butadiene)Pd(R 2 P(CH 2 ) n PR 2 ) compounds has been investigated. The product is a mixture of 1:1 adducts and the rate of reaction is highest when n 2, RPr i and in dichloromethane as solvent. Insight into the mechanism has been obtained by studying the stoichiometric reaction of (η 2 -1,3-butadiene)Pd(Pr
摘要研究了(η2 -1,3-丁二烯)Pd(R 2 P(CH 2)n PR 2)化合物存在下1,3-丁二烯与乙酰乙酸乙酯的催化反应。产物是1:1加合物的混合物,当n 2,RPr i和以二氯甲烷为溶剂时,反应速率最高。通过使用可变温度NMR光谱研究(η2 -1,3-丁二烯)Pd(Pr i 2 PC 2 H 4 PPr i 2)与酯的化学计量反应,已经深入了解了该机理,结果表明:首先形成[(η3 -1-MeC 3 H 4)-Pd(Pr i 2 PC 2 H 4 Ppr i 2)] +物质,该物质进一步反应生成(η2-烯烃)Pd(Pr i 2 PC 2 H 4 Ppr i 2)化合物,其中催化产物与钯原子络合。三个副产物的晶体结构,即。Pd 2(Pr i 2 PCH 2 PPr i 2)2,[(η1,