Catalytic atom-transfer radical cyclization by copper/bipyridine species encapsulated in polysiloxane gel
作者:Yukihiro Motoyama、Kazuyuki Kamo、Akihiro Yuasa、Hideo Nagashima
DOI:10.1039/b923213c
日期:——
Novel polysiloxane gel, in which CuCl/bipyridine species are immobilized, is prepared by treatment of polymethylhydrosiloxane with 4,4′-bis[(2-propenyl)oxy]-2,2′-bipyridine and 1,5-hexadine in the presence of Karstedt′s catalyst followed by addition of CuCl. This polysiloxane gel acts as a reusable catalyst in the atom-transfer radical cyclization of α-halogenated acetamide derivatives in high turnover numbers without allowing leakage of the metal species.
一种新型聚硅氧烷凝胶被制备,通过在Karstedt催化剂的存在下,用4,4′-双[(2-丙烯基)氧]-2,2′-联吡啶和1,5-己二烯处理聚甲基氢硅氧烷,然后加入CuCl。这种聚硅氧烷凝胶在α-卤代乙酰胺衍生物的原子转移自由基环化中作为可重复使用的催化剂,表现出高的循环次数且不允许金属物种泄漏。