Principle of Highly Selective Catalytic Reactions Proceeding through Metal-Olefin Complexes

本研究项目的目的是在分子水平上更好地了解通过金属-烯烃络合物进行的高选择性催化反应。研究结果表明：（1）以-烯烃金属配合物为关键中间体的-烯丙基（烷基）金属配合物的还原消除反应的选择性受金属（Ni）、Pd（Pt）和辅助配体（双膦单膦）的性质控制; 2)烯烃金属络合物转化的选择性取决于烯烃-金属键合方案的性质;即，-烯丙基（烷基）（烯烃）钯向C-C偶合产物的转化被更多吸电子的烯烃配体增强，并且-烯丙基（烯烃）铂向双-铂中间体的转化，这是催化烯烃异构化的关键，通过较高程度的烯烃对金属的电子给予而增强。

The objective of this research project is to gain the better understanding, on the molecular level, of the highly selective catalytic reactions proceeding through metal-olefin complexes. Two primary results obtained during this research include: 1) The selectivity in the reductive elimination of -allyl(alkyl)metal complexes, which involves -olefinmetal complexes as a key intermediate, is controlled by the nature of metal (Ni)>Pd Pt) and the ancillary ligand (diphosphine monophosphine). 2) The selectivity in the transformation of the olefinmetal complexes depend on the nature of the olefin-metal bonding scheme; namely, the transformation of the -allyl(alkyl)(olefin)palladium to the C-C coupling product is enhanced by the more electron-withdrawing olefin ligand, and the transformation of the -allyl(olefin)platinum to a hydrido-platinum intermediate, a key to the catalytic olefin isomerization, is enhanced by the higher degree of olefin to metal electron donation.