(Thio)Amidoindoles and (Thio)Amidobenzimidazoles: An Investigation of Their Hydrogen-Bonding and Organocatalytic Properties in the Ring-Opening Polymerization of Lactide
作者:Sylvain Koeller、Joji Kadota、Frédéric Peruch、Alain Deffieux、Noël Pinaud、Isabelle Pianet、Stéphane Massip、Jean-Michel Léger、Jean-Pierre Desvergne、Brigitte Bibal
DOI:10.1002/chem.200902912
日期:2010.4.12
ring‐opening polymerization (ROP) of lactide catalyzed by two partner hydrogen‐bonding organocatalysts was explored. New amidoindoles 4 a,c, thioamidoindoles 4 b,d, amidobenzimidazoles 5 a,c, and thioamidobenzimidazoles 5 b,c were synthesized and used as activators of the monomer. In the solid state and in solution, compounds 4 and 5 showed a propensity for self‐association, which was evaluated. (Thio)Amides
探索了两种伴侣氢键有机催化剂催化的丙交酯开环聚合(ROP)的机理。新amidoindoles 4,Ç,thioamidoindoles图4b,d,amidobenzimidazoles 5,Ç,和thioamidobenzimidazoles 5b中,Ç合成和用作单体的活化剂。在固态和溶液中,化合物4和5表现出自缔合的倾向,对此进行了评估。在助催化剂叔胺存在下,(硫代)酰胺4和5会催化丙交酯的ROP3a或3b,通过氢键激活正在生长的聚合物链。反应在20°C下2–24小时内进行;转化率在22%至100%之间。对参与物种之间进行的分子间相互作用的详细研究表明,正如预期的那样,同时存在弱氢键来激活试剂。此外,相互作用已经揭示了伙伴催化剂之间4 / 5 + 3。这些伙伴激活剂催化的ROP因此受多重动态平衡支配。应当谨慎地调整后者,以更一般地微调(硫代)酰胺和有机催化剂的催化性能。