Mechanical Activation of Catalysts for C−C Bond Forming and Anionic Polymerization Reactions from a Single Macromolecular Reagent
作者:Andrew G. Tennyson、Kelly M. Wiggins、Christopher W. Bielawski
DOI:10.1021/ja107620y
日期:2010.11.24
colorimetric indicator, or used to catalyze the anionic polymerization of α-trifluoromethyl-2,2,2-trifluoroethyl acrylate. The mechanically induced chain scission also unmasked a catalytically active palladium species which was used to facilitate carbon-carbon bond formation between benzyl cyanide and N-tosyl imines. Spectroscopic and macromolecular analyses as well as a series of control experiments
吡啶封端的聚(丙烯酸甲酯)、PyP(M)(其中 M 对应于 kDa 的数均分子量)与 SCS 环金属化二钯配合物 [(1)(CH(3)CN)(2) 的偶联)] 得到有机金属聚合物 [(1)(PyP(M))(2)],同时分子量增加一倍。对含有 [(1)(PyP(M))(2)] 的溶液进行超声处理会导致钯-吡啶键的机械断裂,其中释放的 PyP(M) 被过量的 HBF(4) 作为相应的吡啶盐捕获,用于影响比色指示剂的化学计量去质子化,或用于催化 α-三氟甲基-2,2,2-三氟乙基丙烯酸酯的阴离子聚合。机械诱导的断链还揭示了催化活性钯物质,该物质用于促进苄基氰化物和 N-甲苯磺酰亚胺之间的碳-碳键形成。光谱和大分子分析以及一系列控制实验表明,上述结构变化源自机械力,机械力源自与上述 Pd 配合物相连的聚合物链的超声诱导解离。