Yang Xinglin, Sun Yonghui, Sun Tian-Yu, Rao Yu
MOE Key Laboratory of Protein Sciences, Department of Pharmacology and Pharmaceutical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China.
Chem Commun (Camb). 2016 May 11;52(38):6423-6. doi: 10.1039/c6cc00234j. Epub 2016 Apr 20.
The direct transformation of unactivated C(sp(3))-H bonds into C-halogen bonds was achieved by palladium catalysis at room temperature with good functional group tolerance. Some drugs and natural products were readily modified by this method. Merged with substitution reaction, newly formed C-X bonds can be transformed into diverse C-O, C-S, C-C and C-N bonds. A preliminary mechanism study demonstrates that solvent is crucial for C-H activation and the C-H activation step is involved in the rate-limiting step. An isolated Pd(ii) intermediate can be transformed into a halogenated product with the retention of conformation which suggests that concerted reductive elimination from Pd(iv) to form a C-X bond was favored.
通过钯催化在室温下实现了未活化的C(sp(3))-H键直接转化为C-卤键，且具有良好的官能团耐受性。一些药物和天然产物可通过该方法轻松修饰。与取代反应相结合，新形成的C-X键可转化为多种C-O、C-S、C-C和C-N键。初步机理研究表明，溶剂对C-H活化至关重要，且C-H活化步骤参与限速步骤。分离得到的Pd(ii)中间体可转化为构型保持的卤代产物，这表明从Pd(iv)协同还原消除形成C-X键是有利的。
