Salicylic aldehydes, amine, and phenyl acetylene could react under the solvent-free, metal-free conditions to form propargylamines 1-4 via A3 coupling reaction. The yield of the reaction was up to 83% for 5h. In acetonitrile, the amine became a catalyst to form 6-bromo-3-(5-bromo-2-hydroxybenzyl)-2-phenyl-4Hchromen-4-one (5). Under microwave conditions, it took about 20 min to complete the reaction and gave the same yields as theconventional method. Structures of these compounds were firm with NMR, MS spectra.
One-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones catalyzed by SO3H@imineZCMNPs as a novel, efficient and reusable acidic nanocatalyst under solvent-free conditions