Catalytic Chain Transfer (co‐)Polymerization: Unprecedented Polyisoprene CCG and a New Concept to Tune the Composition of a Statistical Copolymer

Abstract

Borohydrido-halflanthanidocene/dialkylmagnesium combinations are found to be powerful catalytic systems for the chain transfer polymerization of isoprene and its copolymerization with styrene. A behavior close to a lanthanide catalyzed polyisoprene chain growth on magnesium is reported. Transmetalation is further shown to occur in the course of the statistical copolymerization of isoprene and styrene. For the same monomer feed, the amount of styrene inserted in the copolymer can be increased by a factor 3 using 10 equiv. dialkylmagnesium versus 1 in the range of our experimental conditions. Chain transfer in the course of a metal catalyzed statistical copolymerization may thus be viewed as a new and original way for the control of the composition of a copolymer.

Alkaline-Earth Metal Complexes in Homogeneous Polymerization Catalysis

“…[14,15]. This work was followed by similar efforts from the groups of Zinck and Duchateau who reported that homo-and heteroleptic rare-earth tetrahydroborates and chlorides could be associated to Mg(nBu)(Et) to enable the CGP of isoprene [16] and styrene [17,18] and their copolymerization. Achieving high regio-and stereospecificity in these polymerizations remained troublesome, and it is only recently that truly stereoselective CGP of styrene was documented.…”

Highly trans-1,4-stereoselective coordination chain transfer polymerization of 1,3-butadiene and copolymerization with cyclic esters by a neodymium-based catalyst system

“…46 decrease of stereoregularity was observed by raising the CTA stoichiometry. 17,18,46 Mg(n-Bu) 2 acted as both cocatalyst and CTA in this system. 17,18,46 Mg(n-Bu) 2 acted as both cocatalyst and CTA in this system.…”

“…The past decades have witnessed remarkable advances in a variety of living/controlled polymerization (CLP) techniques such as anionic, cationic, and radical polymerizations that allow the precise control of molecular weight and polydispersity as well as composition of (co)polymers. [13][14][15][16][17][18] In contrast, much less research has been directed at CCTP of 1,3-butadiene (BD), especially for the case of trans-1,4 CCTP. In addition to the common features of CLP techniques, CCTP is of particular interest in terms of catalyst economy, the control and design of polymer microstructure, [1][2][3][4][5] and thus offering the opportunity to prepare a broad range of new classes of precision polymers.…”

Construction of an inducible cell‐communication system that amplifies Salmonella gene expression in tumor tissue

“…We reported the use of lanthanide‐based catalysts combined with metal alkyls for the coordinative chain polymerization (CCTP) and copolymerization of various monomers 11–17. Such a polymerization depicted in Scheme involving the use of a single catalyst and a chain transfer agent (CTA) has gained much interest these last years,18–23 notably due to its potentiality for catalyst economy and molecular weight control, polymer functionalization, and the control of statistical copolymers composition.…”

“…Such a polymerization depicted in Scheme involving the use of a single catalyst and a chain transfer agent (CTA) has gained much interest these last years,18–23 notably due to its potentiality for catalyst economy and molecular weight control, polymer functionalization, and the control of statistical copolymers composition. This latter concept, initially developed for poly(isoprene‐ co ‐styrene) copolymers,14, 17 is extended to poly(styrene‐ co ‐hexene) copolymers in this study. We report herein the use of a half‐lanthanocene/dialkylmagnesium catalytic system for the coordinative chain transfer copolymerization of styrene and hexene.…”