Studies on the Biginelli reaction:: a mild and selective route to 3,4-dihydropyrimidin-2(1H)-ones via enamine intermediates

L-Proline methyl ester hydrochloride was found to be an effective catalyst for assembling (+/-)-dihydropyrimidinones under mild conditions. Mechanistic insights into the useful selectivity elements of this amine-catalyzed process are also reported. (c) 2005 Elsevier Ltd. All rights reserved.