نتایج جستجو برای: metathesis of ethylene

تعداد نتایج: 21167453  

Journal: :Journal of the American Chemical Society 2003
Arnab K Chatterjee Tae-Lim Choi Daniel P Sanders Robert H Grubbs

In recent years, olefin cross metathesis (CM) has emerged as a powerful and convenient synthetic technique in organic chemistry; however, as a general synthetic method, CM has been limited by the lack of predictability in product selectivity and stereoselectivity. Investigations into olefin cross metathesis with several classes of olefins, including substituted and functionalized styrenes, seco...

2011
Didier Astruc Abdou K Diallo Sylvain Gatard Liyuan Liang Cátia Ornelas Victor Martinez Denise Méry Jaime Ruiz

The interplay between olefin metathesis and dendrimers and other nano systems is addressed in this mini review mostly based on the authors' own contributions over the last decade. Two subjects are presented and discussed: (i) The catalysis of olefin metathesis by dendritic nano-catalysts via either covalent attachment (ROMP) or, more usefully, dendrimer encapsulation - ring closing metathesis (...

2017
T. Patrick Montgomery Adam M. Johns Robert H. Grubbs

Olefin metathesis is a prevailing method for the construction of organic molecules. Recent advancements in olefin metathesis have focused on stereoselective transformations. Ruthenium olefin metathesis catalysts have had a particularly pronounced impact in the area of stereoselective olefin metathesis. The development of three categories of Z-selective olefin metathesis catalysts has made Z-ole...

Journal: :Journal of the American Chemical Society 2015
Ho-Keun Lee Ki-Taek Bang Andreas Hess Robert H Grubbs Tae-Lim Choi

We demonstrated tandem ring-opening/ring-closing metathesis (RO/RCM) polymerization of monomers containing two cyclopentene moieties and postmodification via insertion polymerization. In this system, well-defined polymers were efficiently formed by tandem cascade RO/RCM reaction pathway. Furthermore, these polymers could be transformed to new A,B-alternating copolymers via a sequential cross me...

2010
Julia Wappel César A Urbina-Blanco Mudassar Abbas Jörg H Albering Robert Saf Steven P Nolan Christian Slugovc

The aims of this contribution are to present a straightforward synthesis of 2(nd) generation Hoveyda-type olefin metathesis catalysts bearing bromo and iodo ligands, and to disclose the subtle influence of the different anionic co-ligands on the catalytic performance of the complexes in ring opening metathesis polymerisation, ring closing metathesis, enyne cycloisomerisation and cross metathesi...

2007
Miwako Mori

Since the molybdenum and ruthenium carbene complexes 1a and 1b were discovered by Schrock and Grubbs in 1990 and 1992, synthetic organic chemistry has progressed with the use of these complexes as the catalyst for olefin metathesis. It was found that the ruthenium carbene complex was also effective for enyne metathesis, which occurs between an alkene and an alkyne. Intramolecular enyne metathes...

Journal: :Computers & Chemical Engineering 2021

In this work, we propose a superstructure optimization approach for the optimal design of an ethylene and propylene coproduction plant. We formulate that embeds ethane propane steam cracking technologies, dehydrogenation olefin metathesis processes. represent with Generalized Disjunctive Programming model, solve problem through custom implementation Logic-based Outer Approximation algorithm in ...

Journal: :Tetrahedron 2009
Kyu Ok Jeon Dinesh Rayabarapu Alan Rolfe Kelly Volp Iman Omar Paul R Hanson

The development of a ring-opening metathesis/ring-closing metathesis/cross metathesis (ROM-RCM-CM) cascade strategy to the synthesis of a diverse collection of bi- and tricyclic sultams is reported. In this study, functionalized sultam scaffolds derived from intramolecular Diels-Alder (IMDA) reactions undergo metathesis cascades to yield a collection tricyclic sultams. Additional appendage base...

Journal: :Chemical communications 2014
David J Nelson Simone Manzini César A Urbina-Blanco Steven P Nolan

While the fundamental series of [2+2]cycloadditions and retro[2+2]cycloadditions that make up the pathways of ruthenium-catalysed metathesis reactions is well-established, the exploration of mechanistic aspects of alkene metathesis continues. In this Feature Article, modern mechanistic studies of the alkene metathesis reaction, catalysed by well-defined ruthenium complexes, are discussed. Broad...

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