Poly(N-heterocyclic-carbene)s and their CO(2) Adducts as Recyclable Polymer-Supported Organocatalysts for Benzoin Condensation and Transesterification Reactions
VIGNOLLE, Joan
Laboratoire de Chimie des Polymères Organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
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Laboratoire de Chimie des Polymères Organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
VIGNOLLE, Joan
Laboratoire de Chimie des Polymères Organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
Laboratoire de Chimie des Polymères Organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
TATON, Daniel
Laboratoire de Chimie des Polymères Organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
< Réduire
Laboratoire de Chimie des Polymères Organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
Langue
en
Article de revue
Ce document a été publié dans
Macromolecules. 2011, vol. 44, n° 7, p. 1900-1908
American Chemical Society
Résumé en anglais
The synthesis of poly(N-heterocyclic carbene)s, denoted poly-(NHC)s, and of their poly(NHC-CO(2)) adducts for a use in organocatalysis is described. Poly(NHC)s were readily obtained in a three-step sequence of reactions, ...Lire la suite >
The synthesis of poly(N-heterocyclic carbene)s, denoted poly-(NHC)s, and of their poly(NHC-CO(2)) adducts for a use in organocatalysis is described. Poly(NHC)s were readily obtained in a three-step sequence of reactions, involving i) the free-radical polymerization of ionic liquid monomers, that is, 1-vinyl-3-alkylimidazolium-type monomers with bromide (Br(-)) as counteranion, followed by ii) anion exchange of Br(-) for bis(trifluoromethanesulfonyl)imide ((-)NTf2), of the poly(1-vinyl-3-alkylimidazolium bromide) precursors, affording poly(1-vinyl-3-alkylimidazolium bis(trifluorornethanesulfonyl)imide) derivatives, and iii) deprotonation of the latter polymeric ionic liquids with a strong base. Carbon dioxide (CO(2)) was found to reversibly react with poly(NHC)s forming relatively air-stable and thermolabile poly(NHC-CO(2)) adducts. Both poly(NHC)s and their poly(NHC-CO(2)) adducts were used as polymer-supported organic catalysts and precatalysts, respectively, in transesterification and benzoin condensation reactions under homogeneous conditions. Both types of polymer-supported NHCs were recycled and used several times, but the manipulation of poly(NHC)s like their molecular NHC analogues-was more complicated owing to their air and moisture sensitivity. In this regard, zwitterionic poly(NHC-CO(2)) adducts like their molecular NHC-CO(2) analogues could be easier manipulated than their bare poly(NHC) counterparts, providing good to excellent yields even after several organocatalytic cycles, in particular toward the transesterification reaction.< Réduire
Mots clés en anglais
N-HETEROCYCLIC CARBENES
RING-OPENING POLYMERIZATION
IONIC LIQUIDS
BLOCK-COPOLYMERS
CATALYTIC-ACTIVITY
ORGANOMETALLIC CATALYSIS
POLY(ETHYLENE OXIDE)S
LIVING POLYMERIZATION
PYRIDINE OLIGOMERS
OLEFIN METATHESIS
Origine
Importé de halUnités de recherche