Rhodium(III)-Catalyzed Direct Selective C(5)–H Oxidative Annulations of 2-Substituted Imidazoles and Alkynes by Double C–H Activation
摘要:
Double C-H activations of C(5)-H and Csp(2)-H of 2-substituted N-vinyl- or arylimidazoles were realized without heteroatom-directing assistance by rhodium(III) catalyst. A subsequent oxidative annulation reaction with alkynes efficiently produced aza-fused heterocycles with high molecular complexity in low to excellent yields.
Copper-Catalyzed<i>N</i>-Arylation of Hindered Substrates Under Mild Conditions
作者:Michael T. Wentzel、J. Brian Hewgley、Rajesh M. Kamble、Philip D. Wall、Marisa C. Kozlowski
DOI:10.1002/adsc.200800730
日期:2009.4
Abstractmagnified imageA mild, efficient method utilizing a copper‐diamine catalyst at room temperature is reported for the coupling of hindered imidazoles with unsubstituted, ortho‐substituted, and bis‐ortho‐substituted boronic acids in good to excellent yields. Aryl halides do not reaction under these conditions permitting sequential N‐arylation reactions.