Copper(II)-Catalyzed Alkoxyhalogenation of Alkynyl Ureas and Amides as a Route to Haloalkylidene-Substituted Heterocycles
作者:Silvia Gazzola、Egle M. Beccalli、Tea Borelli、Carlo Castellano、Maria Assunta Chiacchio、Daria Diamante、Gianluigi Broggini
DOI:10.1021/acs.joc.5b01227
日期:2015.7.17
A highly effective synthesis of haloalkylidene-substituted heterocycles by copper(II)-catalyzed cyclization of alkynyl ureas and secondary amides has been developed. The reaction, which involves a catalytic amount of CuCl2 and a stoichiometric amount of N-halosuccinimide, occurs selectively through an alkoxyhalogenation process. Alternatively, alkoxychlorination and alkoxybromination reactions can be performed working solely with stoichiometric CuCl, and CuBr2, respectively.