Friedel–Crafts-type reactions with ureas and thioureas
作者:Erum K. Raja、Sten O. Nilsson Lill、Douglas A. Klumpp
DOI:10.1039/c2cc34062c
日期:——
Despite the relatively low reactivities of urea and thiourea functional groups towards nucleophilic attack, we have found conditions in which they are useful substrates in Friedel-Crafts reactions. The Bronsted superacid, triflic acid, promotes these reactions and a mechanism is proposed involving dicationic, superelectrophilic intermediates.