The rapid, simple, microwave-assisted Michael addition of isatin and aniline Schiff base of isatin to a wide variety of alkyl and aryl acrylates in the presence of, tetrabutylammonium bromide (TBAB) and 1,4-diazabicyclo[2.2.2]octane (DABCO), under solvent-free conditions, is presented. Under these conditions the addition of isatin to some of alkyl and aryl acrylates afford both related Baylis-Hillman adducts as minor products and the corresponding Michael adducts as major products. Addition of isatin to ethyl acrylate leads to produce Baylis-Hillman/Michael adduct in good yield. This system dose not work on Michael acceptors of methyl acrylate and methyl methacrylate.

Four-component reaction between primary amines, dialkylacetylendicarboxylates, tetrazolo[1,5-a] quinoline-4-carbaldehyde and ethyl-2-cyanoacetate in the presence of 1,4-diaza-bicyclo[2.2.2]octane and zinc oxide nanoparticles results to the regioselective production of new tetrazolo[1,5-a]quinoline-based 2-amino-1,4-dihydropyridine or pyridin-2(1H)-one derivatives in good to high yields. The selectivity of the catalyzed reaction toward the generation of the dihydropyridine or pyridin-2(1H)-one derivatives was found to be strongly dependent on the size of the alkyl groups in the ester moieties of the acetylenic esters. According to single-crystal X-ray diffraction and NMR studies, the pyridin-2(1H)-one derivatives involve a restricted rotation around the C-C bond connecting the tetrazoloquinoline and dihydropyridinone cyclic systems.

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