Journal ArticleDOI
Synthesis and Applications of RuCl2(CHR‘)(PR3)2: The Influence of the Alkylidene Moiety on Metathesis Activity
TLDR
In this paper, the reactions of RuCl2(PPh3)3 with a number of diazoalkanes were surveyed, and alkylidene transfer was observed for RCHN2 and various para-substituted aryl diazalkanes p-C6H4X CHN2.Abstract:
The reactions of RuCl2(PPh3)3 with a number of diazoalkanes were surveyed, and alkylidene transfer to give RuCl2(CHR)(PPh3)2 (R = Me (1), Et (2)) and RuCl2(CH-p-C6H4X)(PPh3)2 (X = H (3), NMe2 (4), OMe (5), Me (6), F (7), Cl (8), NO2 (9)) was observed for alkyl diazoalkanes RCHN2 and various para-substituted aryl diazoalkanes p-C6H4XCHN2. Kinetic studies on the living ring-opening metathesis polymerization (ROMP) of norbornene using complexes 3−9 as catalysts have shown that initiation is in all cases faster than propagation (ki/kp = 9 for 3) and that the electronic effect of X on the metathesis activity of 3−9 is relatively small. Phosphine exchange in 3−9 with tricyclohexylphosphine leads to RuCl2(CH-p-C6H4X)(PCy3)2 10−16, which are efficient catalysts for ROMP of cyclooctene (PDI = 1.51−1.63) and 1,5-cyclooctadiene (PDI = 1.56−1.67). The crystal structure of RuCl2(CH-p-C6H4Cl)(PCy3)2 (15) indicated a distorted square-pyramidal geometry, in which the two phosphines are trans to each other, and the alkyli...read more
Citations
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Journal ArticleDOI
Chemical Routes for the Transformation of Biomass into Chemicals
TL;DR: Dehydroisomerization of Limonene and Terpenes To Produce Cymene 2481 4.2.1.
Journal ArticleDOI
Autonomic healing of polymer composites
Scott R. White,Nancy R. Sottos,Philippe H. Geubelle,Jeffrey S. Moore,Jeffrey S. Moore,Michael R. Kessler,Suresh R. Sriram,Suresh R. Sriram,Eric Brown,S. Viswanathan +9 more
TL;DR: A structural polymeric material with the ability to autonomically heal cracks is reported, which incorporates a microencapsulated healing agent that is released upon crack intrusion and polymerization of the healing agent is triggered by contact with an embedded catalyst, bonding the crack faces.
Journal ArticleDOI
The Development of L2X2RuCHR Olefin Metathesis Catalysts: An Organometallic Success Story
Tina M. Trnka,Robert H. Grubbs +1 more
TL;DR: The discussion includes an analysis of trends in catalyst activity, a description of catalysts coordinated with N-heterocyclic carbene ligands, and an overview of ongoing work to improve the activity, stability, and selectivity of this family of L2X2Ru=CHR complexes.
Journal ArticleDOI
Synthesis and activity of a new generation of ruthenium-based olefin metathesis catalysts coordinated with 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene ligands.
TL;DR: These air- and water-tolerant complexes were shown to exhibit an increased ring-closing metathesis activity at elevated temperature when compared to that of the parent complex 2 and the previously developed complex 3.
Journal ArticleDOI
Dynamic covalent chemistry.
Stuart J. Rowan,Stuart Cantrill,Graham R. L. Cousins,Jeremy K. M. Sanders,J. Fraser Stoddart +4 more
TL;DR: Some recent examples where dynamic covalent chemistry has been demonstrated are shown to emphasise the basic concepts of this area of science.
References
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Journal ArticleDOI
Ring-Closing Metathesis and Related Processes in Organic Synthesis
TL;DR: The transition metal alkylidene-catalyzed olefin metathesis reaction and the related transition metal-mediated carbonyl olefination reaction are two such processes as discussed by the authors.
Journal ArticleDOI
Catalyse de transformation des oléfines par les complexes du tungstène. II. Télomérisation des oléfines cycliques en présence d'oléfines acycliques
TL;DR: On propose un schema reactionnel en accord avec les faits observes dans la reaction de disproportion des olefines acycliques, la polymerisation des ollines cycliques, the telomerisation of l'olefine cyclique, and the polymerisation of olline cycliques by les olefine acyCLiques as discussed by the authors.
Journal ArticleDOI
Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media
TL;DR: In this paper, an Ru(II) complex with a strained olefin was used to produce a carbene species that polymerizes norbornene in organic media both in the absence and presence of protic/aqueous solvents.
Journal ArticleDOI
Regio- and stereocontrolled dimerization of tert-butylacetylene to (Z)-1,4-di-tert-butylbutatriene by ruthenium catalysis. Reaction mechanism involving alkynyl-vinylidene coupling and rearrangement of the metal-bound C4 unit
Journal ArticleDOI
Multiple metal-carbon bonds. 43. Well-characterized, highly active, Lewis acid free olefin metathesis catalysts
TL;DR: In this article, a complexe de W de type W(CH−t−Bu)(NR)(OR') 2, OR'=OC(Me)(CF 3 ) 2
Related Papers (5)
Synthesis and activity of a new generation of ruthenium-based olefin metathesis catalysts coordinated with 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene ligands.
A Series of Well‐Defined Metathesis Catalysts–Synthesis of [RuCl2(CHR′)(PR3)2] and Its Reactions
The Development of L2X2RuCHR Olefin Metathesis Catalysts: An Organometallic Success Story
Tina M. Trnka,Robert H. Grubbs +1 more