title: Manganese catalyzed C-H functionalization of indoles with alkynes to synthesize bis/trisubstituted indolylalkenes and carbazoles: the acid is the key to control selectivity.
abstract: The Mn-catalyzed C-H alkenylation reactions of indole with terminal- and internal-alkynes have been developed. In the presence of a catalytic amount of acid, the procedure efficiently affords bis/trisubstituted indolyl-alkenes in a highly regio- and stereo-selective manner. Without the addition of acid, the reaction undergoes a [2+2+2] cyclization process to give carbazoles with release of hydrogen gas. Notably, the directing pyrimidyl group can be readily removed. Experimental studies reveal that the reaction is initiated by a C-H activation step and the acid is the selectivity controller via a hydrogen transfer process.
authors: Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China. Leizq@nwnu.edu.cn.
authors: Lijun
authors: L
authors: Shi
authors: Xiang
authors: X
authors: Zhong
authors: Houde
authors: H
authors: She
authors: Ziqiang
authors: Z
authors: Lei
authors: Fuwei
authors: F
authors: Li