Ruthenium olefin metathesis catalysts with modified styrene ethers: influence of steric and electronic effects
作者:Mirko Zaja、Stephen J Connon、Aideen M Dunne、Michael Rivard、Nicole Buschmann、Jan Jiricek、Siegfried Blechert
DOI:10.1016/s0040-4020(03)01029-9
日期:2003.8
A series of olefin metathesis catalysts with modified isopropoxybenzylidene ligands were synthesised, and the effects of ligands on the rate of metathesis investigated. Increased steric hinderance ortho to the isopropoxy group enhanced reaction rates. In the case of N-heterocyclic carbene complexes, decreasing electron density at both the chelating oxygen atom and the RuC bond accelerated reaction
合成了一系列具有修饰的异丙氧基亚苄基配体的烯烃复分解催化剂,并研究了配体对复分解速率的影响。与异丙氧基相邻的位阻增加,反应速率提高。在N-杂环卡宾配合物的情况下,在螯合氧原子和RuC键上电子密度的降低明显地促进了反应速率。含有三环己基膦配体的催化剂在亚苄基亲电性方面遵循相同的趋势,而在氧气下较高的电子密度提高了反应速率。