Abstract:
A cobalt-catalyzed intramolecular Markovnikov hydroalkoxycarbonylation and hydroaminocarbonylation of unactivated alkenes has been developed, enabling highly chemo- and regioselective synthesis of α-alkylated γ-lactones and α-alkylated γ-lactams in good yields. The mild reaction conditions allow use of mono-, di- and trisubstituted alkenes bearing a variety of functional groups. Preliminary mechanistic studies suggest the reaction proceeds through a CO-mediated hydrogen atom transfer (HAT) and radical-polar crossover (RPC) process, in which a cationic acylcobalt(IV) complex is proposed as the key intermediate.
摘要:
已开发出钴催化的分子内Markovnikov氢烷氧基羰基化和未活化烯烃的氢氨基羰基化,能够以良好的产率高度化学和区域选择性合成α-烷基化γ-内酯和α-烷基化γ-内酰胺。温和的反应条件允许使用单-,带有各种官能团的二取代和三取代的烯烃。初步机理研究表明,反应通过CO介导的氢原子转移(HAT)和自由基-极性交叉(RPC)过程进行,其中提出阳离子酰基钴(IV)配合物作为关键中间体。