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.
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.