Water-Promoted Synthesis of Enaminones: Mechanism Investigation and Application in Multicomponent Reactions
摘要:
Highly stereoselective synthesis of Z-enaminones bearing reactive secondary amino group has been successfully performed in water using tertiary amino group functionalized enaminones under ambient conditions. An interesting promotion effect of water on the reaction via hydrolysis-dehydration condensation has been observed through a designed isotope labeling experiment. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) to view the free supplemental file.
Phenylphosphinic acid is found to catalyze the three-component condensation of an aldehyde, enaminone, and urea or thiourea to afford the corresponding 6-unsubstituted dihydropyrimidinones in high to excellent yields. This methodology is simple and fast synthetic route for the preparation of interesting class of heterocycles.
A one-pot three-component Biginelli-like reaction of enaminones, aldehydes with urea/thiourea in the presence of 2-pyrrolidonium bisulphate as an acidic ionicliquidcatalyst for the preparation of 6-unsubstituted dihydropyrimidinones is described. The excellent yield, short reaction time, simple procedure and avoidance of the use of organic solvents are some advantages of this method.
Chemo-/regioselective synthesis of 6-unsubstituted dihydropyrimidinones, 1,3-thiazines and chromones via novel variants of Biginelli reaction
作者:Jie-Ping Wan、Yuan-Jiang Pan
DOI:10.1039/b901112a
日期:——
A novel and facile cascade Biginelli-like assembly employing enaminone, aldehyde and urea/thiourea has been developed, which provides a highly chemo- and regioselective synthesis of new dihydropyrimidinones, 1,3-thiazines and chromones by altering particular functional groups in the reactants.