作者:Gang Li、Jonathan L. Kuo、Arthur Han、Janine M. Abuyuan、Lily C. Young、Jack R. Norton、Joshua H. Palmer
DOI:10.1021/jacs.6b03509
日期:2016.6.22
concentration of an H• donor. Transfer of the H• onto an olefin gives a radical that can either (1) transfer an H• back to the metal, generating an isomerized olefin, or (2) add intramolecularly to a double bond, generating a cyclized radical. Transfer of an H• back to the metal from the cyclized radical results in a cycloisomerization. Both outcomes are favored by the low concentration of the cobalt H• donor,
在 H2 压力下,Co(II)(dmgBF2)2L2 (L = H2O, THF) 生成低浓度的 H• 供体。H• 转移到烯烃上会产生一个自由基,它可以 (1) 将 H• 转移回金属,生成异构化烯烃,或 (2) 分子内加成到双键上,生成环化自由基。H• 从环化自由基转移回金属导致环异构化。低浓度的钴 H• 供体有利于这两种结果,而使用其他催化剂(当 H• 供体的浓度高时)更有可能发生氢化和环氢化。