Iodine efficiently catalyzes the Biginelli reaction. This procedure involves a one-pot three-component cyclocondensation of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea to afford the corresponding 3,4-dihydropyrimidin-2(1H)-ones or thiones in high yields.
iodine - aldehydes - 1,3-dicarbonyl compounds - urea - thiourea - one-pot condensation - dihydropyrimidin-ones and thiones - Biginelli reaction