New Ytterbium Complex-catalyzed Multicomponent Reactions for Synthesis of Dihydropyrimidines: [4+2] Cycloaddition vs. Biginelli Type Reaction
作者:Jie Zhu、Mingjie Zhang、Bo Liu、Xiaojuan Li
DOI:10.1246/cl.2009.56
日期:2009.1.5
A new schiff base ytterbium complex was synthesized and used as catalyst for a three-component, one-potreactioninvolving 1,3-keto ester with urea or thiourea and aldehyde. The reactions resulted ...
Pyrimidine derivatives, 4a-4m , were synthesized in high yield using a newly developed microwave-assisted cyclocondensation reaction of g -ketoester, aryl aldehyde, and (thio)urea. In all of these Biginelli reactions, a mixture of the appropriate g -ketoester, aryl aldehyde, and (thio)urea were subjected to microwave irradiation by using polyphosphateester (PPE) as a reaction moderator. 1 H NMR and