NBS-mediated sequential one-pot synthesis of multifunctionalized thiazoles and thiophenes from 1,3-dicarbonyl compounds and mercaptonitrile salts

A NBS-mediated sequential one-pot synthesis of multifunctionalized thiazoles and thiophenes from 1,3-dicarbonyl compounds and mercaptonitrile salts has been developed under mild conditions. This transformation involves sequential bromination/SN2 alkylation/Thorpe-Ziegler cyclization/regio-selective elimination of a -COR group, affording the desired products in moderate to good yields. The sequence of the leaving reactivity of -COR groups was determined and a possible mechanism was proposed.