Rh(III)-Catalyzed Oxidative Annulation of 2-Phenylimidazo[1,2-<i>a</i>]pyridines with Alkynes: Mono versus Double C–H Activation
作者:Zisong Qi、Songjie Yu、Xingwei Li
DOI:10.1021/acs.joc.5b00059
日期:2015.4.3
Rh(III)-catalyzed C–H activation of 2-phenylimidazo[1,2-a]pyridines in divergent oxidative coupling with alkynes has been achieved. Selective mono versus 2-fold C–H activation has been attained under condition control. When AgOAc was used as an oxidant, the coupling afforded 5,6-disubstituted naphtho[1′,2′:4,5]imidazo[1,2-a]pyridines as a result of initial nitrogen chelation-assisted C–H activation
在与炔烃的发散性氧化偶合中,Rh(III)催化了2-苯基咪唑并[1,2- a ]吡啶的C–H活化。在条件控制下,选择性的单峰激活和2倍C–H激活已实现。当AgOAc用作氧化剂时,由于最初的氮螯合辅助的C–H活化,偶联产生了5,6-二取代的萘并[1',2':4,5]咪唑并[1,2- a ]吡啶在苯环上,然后进行C–H翻转激活。相反,当将AgBF 4用作助氧化剂时,由于C–C和C–N偶联,反应生成了稠合的异喹啉鎓盐。分离了一个Rhodocyclic中间体。