Latent olefin metathesis catalysts

Olefin metathesis is a versatile synthetic tool for the redistribution of alkylidene fragments at carbon-carbon double bonds. This field, and more specifically the development of task-specific, latent catalysts, attracts emerging industrial and academic interest. This tutorial review aims to provide the reader with a concise overview of early breakthroughs and recent key developments in the endeavor to develop latent olefin metathesis catalysts, and to illustrate their use by prominent examples from the literature

ROMP of novel hindered phenol-functionalized norbornenes and preliminary evaluation as stabilizing agents†

A series of new norbornene monomers containing sterically hindered phenol groups have been synthesized and polymerized via ring-opening metathesis polymerization (ROMP) using the Grubbs 3rd generation catalyst (G3’). ROMPs exhibit first-order kinetics and molar masses increase linearly with monomer conversion and well-controlled phenol hindered-functionalized polynorbornenes were obtained with a monomer to initiator ratio up to 1 000. The first-order rate constants show that the ROMP activity is closely associated with the norbornene monomer steric congestion. The antioxidant behavior of these hindered phenol-containing polynorbornenes with different para-bridged side groups in polypropylene (PP) was estimated by onset oxidation temperature (OOT) measurements. The ability of these hindered phenol-containing norbornenes to copolymerize by ROMP with dicyclopentadiene (DCPD) was used to bound covalently the antioxidant moiety onto a polydicyclopentadiene (PDCPD) resin whose thermal ageing has been investigated.We thank Mireille Barthe and Alexandre Bénard for SEC analyses and Sullivan Bricaud for NMR analyses. We acknowledge finan- cial support from Le Mans University, CNRS, and the French National Research Agency (VRPOM project, ANR-15-CE08-0025)

Enhanced catalyst performance through activity control : latent ruthenium catalysts in Ring-Opening Metathesis Polymerisation reactions

This article discusses the gaps and opportunities within the realm of olefin metathesis technology using ruthenium-based catalysts. Addressing the needs for industrial applications, a straightforward method for the Ring-Opening Metathesis Polymerisation (ROMP) of dicyclopentadiene (DCPD) in a Reaction Injection Moulding (RIM) process is described. Our approach was constituted of the synthesis of a latent Ru catalyst which could be chemically activated on demand. Results provide prove of a high degree of catalyst latency while high catalytic activity is obtained upon addition of Bronsted or Lewis acids. High turn over numbers (TON's) were obtained for the ROMP of cyclo-1,5-octadiene (COD) and dicyclopentadiene (DCPD), respectively 630.000 and 60.000

Synthetic approach to ruthenium vinylidene complexes and their applications in metathesis catalysis

Convenient routes for synthesis of ruthenium vinylidene complexes have been described, the majority of which use alkynes along with a ruthenium source as the main starting materials. Their successful application as efficient precatalysts in synthesis of heterocyclic and carbocyclic compounds by ring-closing metathesis of alpha,omega-dienes and in the synthesis of polymers by ring-opening metathesis polymerization of cyclooctene, norbornene, 5-substituted norbornene and dicyclopentadiene are fully illustrated. Relevant aspects concerning the activity and stereoselectivity in metathesis reactions of this type of Ru complexes are highlighte

Does glass reinforced PDCPD retain the toughness of the bulk matrix?

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