Rhodium-Catalyzed Enantioselective Radical Addition of CX<sub>4</sub>
Reagents to Olefins
作者:Bo Chen、Cheng Fang、Peng Liu、Joseph M. Ready
DOI:10.1002/anie.201704074
日期:2017.7.17
We describe the synthetically useful enantioselective addition of Br−CX3 (X=Cl or Br) to terminal olefins to introduce a trihalomethyl group and generate optically active secondary bromides. Computational and experimental evidence supports an asymmetric atom‐transfer radical addition (ATRA) mechanism in which the stereodetermining step involves outer‐sphere bromine abstraction from a [(bisphosphine)RhIIBrCl]
我们描述了Br-CX 3(X = Cl或Br)的合成有用的对映选择性加成到末端烯烃中以引入三卤甲基并生成光学活性的仲溴化物。计算和实验证据支持不对称原子转移自由基加成(ATRA)机理,其中立体确定步骤涉及通过苄基自由基中间体从[(bisphosphine)Rh II BrCl]络合物中提取外层溴。这种机理在不对称催化中显得空前。