Efficient synthesis of di- and trisubstituted 2-aryloxazoles via ytterbium(III) triflate catalyzed cyclization of tertiary propargylic alcohols with aryl amides
作者:Xiaoxiang Zhang、Wan Teng Teo、Philip Wai Hong Chan
DOI:10.1016/j.jorganchem.2010.09.059
日期:2011.1
based on Yb(OTf)3 catalyzed cyclization of trisubstituted propargylic alcohols with aryl amides is described. The reaction was accomplished in moderate to excellent product yields and with complete regioselective control. The mechanism is suggested to involve activation of the starting alcohol by the metal catalyst that results in its ionization. Subsequent cyclization of this newly generated carbocationic