An efficient one-pot synthesis of 2-oxazolines with molecular iodine under ultrasound irradiation
作者:Nan Xiao、Sen Hao Wang、Ai Ying Zhang、Hong Yang Li、Peng Wang、Wei Li、Bao Hua Chen、Guo Feng Chen、Na Li
DOI:10.1007/s11164-015-1961-1
日期:2015.12
A series of 2-oxazolines were prepared by the condensation of aldehydes with 2-aminoethanol in the presence of molecular iodine and potassium carbonate in t-BuOH at 35–40 °C under ultrasound irradiation. The easy work-up procedure and moderate to good yields are the advantages of this methodology.
Oxazoline is OK! A general and efficient method for the synthesis of oxazolines has been developed (see scheme). This allowed the preparation of 27 five‐membered‐ring heterocycles and 11 six‐membered‐ring heterocycles in moderate to good yields.
Over the past two decades, transition-metal-catalyzed C–H activation and the subsequent oxidative cyclization with alkynes or their surrogates has emerged as a powerful synthetic tool for fused heteroaromatics. We report a Rh(III)-catalyzed annulation and ring-opening cascade reaction with 2-aryloxazolines. By utilizing a vinyl selenone as an oxidizing acetylene surrogate, the target three-component coupling products were obtained in high yields without using a stoichiometric amount of external oxidant.