Aldehydes, alkynic Knoevenagel reaction

Jiang et al. described the proline-catalyzed reaction of several amines 143 with alkynes 141, various aldehydes 142, and 1,3-dicarbonyl compounds 144 to afford 1,4-dihydro-pyridines 145 in moderate to good yields (65-85%) (Scheme 13.37) [62]. Mainly three reactions are involved in the production of those products the first one is a proline-catalyzed Knoevenagel reaction between the aldehydes 142 and the 1,3-dicarbonyl compounds 144 to give Michael acceptors. The second one is a hydroamination reaction of the alkyne 141 to yield enamines, which in the third reaction undergo an enamine-Michael addition/cyclization sequence to provide the desired products. 

Thiazolidinedione -triazole hybrids maybe synthesized by the one-pot reaction based on a Knoevenagel condensation followed by an alkyne-azide cycloaddition, between thiazolidine-2,4-dione, substituted aryl aldehydes, propargyl bromide, and substituted aryl azides using piperidine. The catalytic system is composed of CuS04 5H20 and sodium ascorbate in PEG-400 [119]. 

---