Mechanism of ruthenium-catalyzed olefin metathesis reactions from a theoretical perspective

被引:236
作者
Cavallo, L [1 ]
机构
[1] Univ Salerno, Dipartimento Chim, I-84081 Baronissi, Salerno, Italy
关键词
D O I
10.1021/ja016772s
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
This paper presents a density functional theory study of the ruthenium-catalyzed clef in metathesis reactions. The ligand binding energy has been calculated in the first generation of Grubbs-type (PCy3)(2)-Cl2Ru=CHPh (pre)catalyst, as well as in the heteroleptic (pre)catalytic systems in which a N-heterocyclic carbene, NHC, ligand substitutes a single phosphine. In agreement with experiments PCy3 coordinates more strongly to Ru in the heteroleptic (pre)catalysts than in the Grubbs-type (pre)catalyst. Moreover, ethene coordination and insertion into the Ru-alkylidene bond in the above-mentioned systems, as well as in the Hofmann type catalytic system with a cis-coordinated phosphane ligand, has been studied. The calculated insertion barrier for the NHC systems are lower than that of the (PCy3)(2)Cl2Ru=CHPh system. This is consistent with the higher activity experimentally observed for the NHC-based system.
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页码:8965 / 8973
页数:9
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