Synthesis and Activity of a New Generation of Ruthenium-Based Olefin Metathesis Catalysts Coordinated with 1,3-Dimesityl-4,5-dihydroimidazol-2-ylidene Ligands
作者:Matthias Scholl、Sheng Ding、Choon Woo Lee、Robert H. Grubbs
DOI:10.1021/ol990909q
日期:1999.9.1
[formula: see text] A new family of 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene-substituted ruthenium-based complexes 9a-c has been prepared starting from RuCl2(=CHPh)(PCy3)2 2. These air- and water-tolerant complexes were shown to exhibit an increased ring-closing metathesisactivity at elevated temperature when compared to that of the parent complex 2 and the previously developed complex 3. In many
Increased ring closing metathesis activity of ruthenium-based olefin metathesis catalysts coordinated with imidazolin-2-ylidene ligands
作者:Matthias Scholl、Tina M. Trnka、John P. Morgan、Robert H. Grubbs
DOI:10.1016/s0040-4039(99)00217-8
日期:1999.3
The novel air and water tolerant, imidazolinylidene-substituted ruthenium-based complex 3, has been prepared starting from RuCl2(=CHPh)(PCy3)(2) 2 and shown to exhibit increased ring-closing metathesis activity at elevated temperature compared to that of the parent complex 2. Di-, tri-, and even tetra-substituted cycloolefins were successfully prepared from corresponding diene precursors using catalytic amounts of 3 in moderate to excellent yields. (C) 1999 Elsevier Science Ltd. All rights reserved.
Oligomers as Intermediates in Ring-Closing Metathesis
作者:Jay C. Conrad、Melanie D. Eelman、João A. Duarte Silva、Sebastien Monfette、Henrietta H. Parnas、Jennifer L. Snelgrove、Deryn E. Fogg
DOI:10.1021/ja067531t
日期:2007.2.1
Oligomerization is kinetically favored in RCM reactions catalyzed by RuCl2(PCy3)(IMes)(=CHPh), for a range of unhindered , alpha,omega-dienes leading to large or medium-sized rings, even at dilutions designed to minimize intermolecular reaction. Reversible metathesis (i.e., ethenolysis) is inhibited by rapid volatilization of ethylene. At appropriately high dilutions, however, the RCM products are efficiently liberated by backbiting.