Catalyst-Controlled Regiodivergent Alkyne Insertion in the Context of C−H Activation and Diels-Alder Reactions: Synthesis of Fused and Bridged Cycles
作者:Xukai Zhou、Yupeng Pan、Xingwei Li
DOI:10.1002/anie.201704036
日期:2017.7.3
Rhodium(III)- and cobalt(III)-catalyzed C−H activation of indoles and coupling with 1,6-enynes is discussed. Under rhodium(III) catalysis, the alkyne insertion follows 2,1-regioselectivity with a subsequent type-I intramolecular Diels–Alder reaction (IMDA) to afford [6,5]-fused cycles. When catalyzed by the cobalt(III) congener, 1,2-insertion of the alkyne is preferred, and followed by a rare type-II
讨论了铑(III)和钴(III)催化吲哚的CH活化以及与1,6-炔烃的偶联。在铑(III)催化下,炔烃的插入遵循2,1-区域选择性,随后发生I型分子内Diels-Alder反应(IMDA),从而得到[6,5]稠合的循环。当被钴(III)同源物催化时,优选炔烃的1,2-插入,然后是稀有的II型IMDA,从而导致桥连的[3,3,1]循环。炔烃插入的选择性主要通过催化剂的空间敏感性来调节。