Evidence for Formation of a Co-H Bond from (H2O)2Co(dmgBF2)2 under H2: Application to Radical Cyclizations
Evidence for Formation of a Co-H Bond from (H2O)2Co(dmgBF2)2 under H2: Application to Radical Cyclizations
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DOI：
10.1021/ja306037w
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发表时间：
2012-09-12
影响因子：
15
通讯作者：
Norton, Jack R.
中科院分区：
文献类型：
--
作者：
Li, Gang;Han, Arthur;Norton, Jack R.
在H-2条件下，钴胺可以催化适当的二烯的自由基环化。氢中心点可以通过三烷基自由基（Ar3C中心点）或TEMPO从中间体（可能是氢化钴）中提取出来。这些反应的速率决定步骤是H-2的吸收，在钴中是二级反应，在氢中是一级反应；三阶速率常数是106(3)m -2 - s（-1）
Under H-2, the radical cyclization of appropriate dienes can be catalyzed by cobaloximes. H center dot can be abstracted from an intermediate (presumably a cobalt: hydride) by trityl radicals (Ar3C center dot) or by TEMPO. The rate-determining step in these reactions is the uptake of H-2, which is second order in cobalt and first order in hydrogen; the third-order rate constant is 106(3) M-2.s(-1).