Here we present the first experimental study to isolate and identify a surface tantalum carbene as the intermediate in alkane metathesis a systematic experimental study reveals a new reasonable pathway for this reaction pmid: 25557135. Alkane metathesis via tandem catalysis - ebook download as pdf file (pdf), text file (txt) or read book online. Polyethylene (pe) is the largest-volume synthetic polymer, and its chemical inertness makes its degradation by low-energy processes a challenging problem we report a tandem catalytic cross alkane metathesis method for highly efficient degradation of polyethylenes under mild conditions with the. Chemists find new way to recycle plastic waste into fuel approach tackles most commonly used synthetic plastic their innovative technique centers on the use of alkanes the team degrades plastics in a milder and more efficient manner through a process known as cross-alkane metathesis.
Alkane metathesis in alkane metathesis acyclic alkanes are scrambled to higher and lower homologues with tantalum hydride supported on silica (sio2)tah at. Metathesis reactions, which involve the exchange of chemical groups between reactants, are well known for alkenes and alkynes vidal et al ([p 99]) show that metathesis reactions can also occur for the much less reactive alkanes they used transition metal hydride catalysts to transform linear. Alkane metathesis is a class of chemical reaction in which an alkane is rearranged to give a longer or shorter alkane product it is similar to olefin metathesis, except that olefin metathesis cleaves and recreates a carbon-carbon double bond, but alkane methathesis operates on a carbon-carbon. A tandem system for the metathesis of n-alkanes, comprising pincer-ligated alkane-dehydrogenation catalysts and either schrock-type or heterogeneous olefin-metathesis catalysts, was recently reported by the groups of brookhart and goldman. Catalytic alkane metathesis by tandem alkane dehydrogenation- olefin metathesis fischer-tropsch alkane metathesis tandem alkane dehydrogenation- olefin metathesis molecular redistribution mechanism by olefin intermediates.
An alkane metathesis catalyst can include a high oxidation state group v, vi or vh metal alkyl on an oxide support. Olefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the scission and regeneration of carbon-carbon double bonds. Abstract a fully heterogeneous and highly efficient dual catalyst system for alkane metathesis (am) has been developed the system is comprised of an alumina-supported iridium pincer catalyst for alkane dehydrogenation/olefin hydrogenation and a second heterogeneous olefin metathesis catalyst. Organoiridium complexes catalyze the dehydrogenation of alkanes and alkyl groups, a transformation with tremendous potential applicability for example, alkane dehydrogenation in tandem with olefin metathesis results in alkane metathesis. The goldman group - selected publications alkane metathesis by tandem alkane-dehydrogenation-olefin metathesis catalyst and related chemistry michael c haibach, sabuj kundu, maurice brookhart, and alan s goldman acc chem. Ty - jour t1 - alkane metathesis by tandem alkane-dehydrogenation-olefin-metathesis catalysis and related chemistry au - haibach,michael c au - kundu,sabuj.
View this abstract online primary products and mechanistic considerations in alkane metathesis j am chem soc 2005 127(24):8604-5 (issn: 0002-7863. Alkane metathesis and other tandem systems for catalytic hydrocarbon transformations olefins are ubiquitous as intermediates in the petrochemical, commodity chemical, and pharmaceutical industries.
Abstract with petroleum supplies dwindling, there is increasing interest in selective methods for transforming other carbon feedstocks into hydrocarbons suitable for transportation fuel. Discusses olefin (alkene) metathesis reactions part of an organometallic hypertext. Alkyne metathesis is an organic reaction involving the redistribution of alkyne chemical bonds this reaction is closely related to olefin metathesis. Faculty research goldman, alan distinguished professor research synopsis: catalysis and catalytically relevant organometallic chemistry, reactions, and mechanisms alkane metathesis and other tandem systems for catalytic hydrocarbon transformation. Alkane metathesis transforms small alkanes into their higher and lower homologues the reaction is catalyzed by either supported d(0) metal hydrides (m = ta, w) or d(0) alkyl alkylidene complexes (m = ta, mo, w, re) for the silica-supported tantalum hydrides, several reaction mechanisms have.