Metathesis catalysts for

An alternative to elucidating the active sites on a surface is to synthesize them. For example, a new catalyst for metathesis of alkanes. 

For a thorough review of Ru-NHC-catalysts for metathesis, see Samojlowicz C, Bieniek M, Grela K (2009) Chem Rev 109 3708-3742 for ruthenium indenylidene-complexes in cross metathesis, see Boeda F, Bantreil X, Clavier H, Nolan SP (2008) Adv Synth Catal 350 2959-2966 For Hll-types systems, see Schrodi Y, Pederson RL (2007) Aldrichimica Acta 40 45-52... 

WO 2009/124853 Al, F Hoffmann-La Roche AG New ruthenium complexes as catalysts for metathesis reactions... 

Diver has recently reported new entries for the assembly of tetracyclic compounds.304 Interestingly, ruthenium catalysts for metathesis have also yielded tricyclic products by incorporating a cyclopropane from dienynes, a process reminiscent of Dixneuf s work (see above). 

Electrophilic metal carbene complexes such as (CO)5W=C(Ph)OMe generally exhibit poor activity as catalysts for metathesis polymerisation, and higher temperatures are required to bring about the polymerisation of high-strained cycloolefins such as norbornene or cyclobutene [84,85], However, their activity can be enhanced by the addition of a Lewis acid such as TiCL into the polymerisation system [86]. Electrophilic complexes such as (CO)5W=CPh2 also generally exhibit poor activity but they are more active than those mentioned above and enable the polymerisation of various cycloolefins [87,88],... 

Richard Royce Schrock was the youngest of the three Nobel laureates, who received the prize in Chemistry 2005. In the press release from the Royal Swedish Academy of Sciences it was emphasized that, based on the ideas of Chauvin, he and Grubbs made metathesis into one of organic chemistry s most important reactions . And it continued that Schrock was the first to produce an efficient metal-compound catalyst for metathesis . 

A classical catalyst for metathesis reactions 1 reminiscent of a polymerization Ziegler catalyst it is essentially a combination of a transition metal halide (WCU. MoCl ) and an alkyl metal derivative (AIR). SnK. etc). It is noteworthy that a reduction step occurs during the constitution of the active center, since an elTicieni metathesis of terminal olefins has been achieved under electro-catalytic conditions [40]. (CI4 being the active carbenic entities in... 

As discussed above in the mechanism of the alkene dimerization reaction, the polymerization of simple alkenes proceeds by the basic metathesis mechanism. Since polymers that are prepared from complex monomers require homogeneous catalysts, much of the early organometallic catalyst development has had polymer synthesis as the driving force. Recently, developments in the synthesis of organometal-lic complexes that serve as well-defined catalysts for metathesis have opened many opportunities in the area of polymer synthesis. ... 

Buchmeiser, M. R. Well-defined transition metal catalysts for metathesis polymerization. Late Transition Metal Polymerization Catalysis... 

Thieuleux, C., Coperet, C., Dufaud, V., Marangelli, C., Kuntz, E., Basset, J. M. Heterogeneous well-defined catalysts for metathesis of inert and not so inert bonds. J. Mol. Catal. A Chemical 2004, 213, 47-57. 

Recent years have seen rapid advancements in development of W, Mo, and Ru carbene complexes that serve not only as catalysts for metathesis of small molecules (Section 11-1-3) but also as ROMP catalysts. Grubbs use of a Ru(III) catalyst for ROMP in aqueous medium helped pave the way for development of his first- and second-generation Ru alkylidenes, which also catalyze ROMP. The Schrock catalysts that we have encountered already (compounds 15... 

Well-Defined Transition Metal Catalysts for Metathesis Polymerization... 

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