Synthesis and reactivity of novel ruthenium carbene catalysts. X-ray structures of [RuCl2(CHSC6H5)(PiPr3)2] and [RuCl2(CHCH2CH2-C,N-2-C5H4N)(PiPr3)]
摘要:
Two novel classes of very air-stable ruthenium carbene complexes have been developed. The arylthio substituted ruthenium carbenes containing two bulky phosphines are deep purple solids, whereas the 2-pyridylethanyl substituted ruthenium carbene complexes contain only one bulky phosphine and are light-brown colored. One member of each class has been characterized with X-ray crystallography. The metathesis activity of these complexes has been investigated in the polymerization of dicyclopentadiene. Several excellent catalysts were identified. Desired geltimes and initiation temperatures could be easily tuned by changing the substitution pattern on the pendant ligand in the 2-pyridylethanyl substituted ruthenium carbenes. (C) 2000 Elsevier Science S.A. All rights reserved.
A set of heterogenized olefin‐metathesis catalysts, which consisted of Ru complexes with the H2ITap ligand (1,3‐bis(2′,6′‐dimethyl‐4′dimethyl aminophenyl)‐4,5‐dihydroimidazol‐2‐ylidene) that had been adsorbed onto a silica support, has been prepared. These complexes showed strong binding to the solid support without the need for tethering groups on the complex or functionalized silica. The catalysts
一套异质烯烃复分解催化剂,由Ru与H 2 ITap配体(1,3-双(2',6'-二甲基-4'二甲基氨基苯基)-4,5-二氢咪唑-2-基亚烷基)组成已经制备了已被吸附到二氧化硅载体上的)。这些络合物显示出与固相载体的牢固结合,而无需络合物或功能化二氧化硅上的束缚基团。在连续流动条件下,在环辛烯(COE)的开环-开环-复分解(RO-RCM)和油酸甲酯的自我复分解中对催化剂进行了测试。最佳配合物的TON> 4000,超过了先前报道的基于二氧化硅上的Grubbs-Hoveyda II配合物或经典的异质Re 2 O 7 / B的材料。2 O 3催化剂。
Latent Ruthenium Olefin Metathesis Catalysts That Contain an N-Heterocyclic Carbene Ligand
作者:Thay Ung、Andrew Hejl、Robert H. Grubbs、Yann Schrodi
DOI:10.1021/om0493210
日期:2004.11.1
A new N-heterocyclic carbenecontaining olefin metathesis catalyst, (sIMes)(Cl)2Ru(CH(CH2)2-C,N-2-C5H4N) (4a), was synthesized from (sIMes)(PCy3)(Cl)2RuCHPh (1) or (sIMes)(py)2(Cl)2RuCHPh (3). When heated at 40 °C in dichloromethane, 4a is slowly converted to its isomer 4b. The X-ray structures of 4a and 4b show that the NHC and pyridine ligands are trans in 4a and cis in 4b. 4a is more latent than
Latent, high-activity olefin metathesis catalysts containing an N-heterocyclic carbene ligand
申请人:Ung Thay
公开号:US20050261451A1
公开(公告)日:2005-11-24
The invention provides novel organometallic complexes useful as olefin metathesis catalysts. The complexes have an N-heterocyclic carbene ligand and a chelating carbene ligand associated with a Group 8 transition metal center. The molecular structure of the complexes can be altered so as to provide a substantial latency period. The complexes are particularly useful in catalyzing ring closing metathesis of acyclic olefins and ring opening metathesis polymerization of cyclic olefins.