KF/Al2O3Mediated Multicomponent Reactions for the Efficient Synthesis of Highly Substituted Dihydropyridines

Visible-light-induced organophotocatalytic and singlet oxygen-initiated domino construction of 1,4-dihydropyridines, C-3 functionalized spiro[indoline-3,4'-pyridines] and C-11 functionalized spiro[indeno-[1,2-b]quinoxaline-11,4'-pyridines]

A highly efficient pot, atom, and step economical method for the construction of pharmacologically potent structurally functionalized 1,4-dihydropyridines, quaternary centered C-3 functionalized spiro[indoline-3,4'-pyridines], and C-11 functionalized spiro[indeno[1,2-b]quinoxaline-11,4'-pyridines] via rose bengal photoredox catalysis under blue LED irradiation in an aqueous medium at room temperature has been developed. The products were isolated in excellent yields within a short reaction time for a variety of functional groups under transition metal- and ligand-free energy-efficient conditions in a green solvent system with high reaction mass efficiency and process mass intensity, which are the key advantages of the current work.

Visible Light Mediated, Catalyst Free, One-Pot Convenient Synthesis of Dihydropyridines

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A simple, efficient and green protocol has been developed for the synthesis of polysubstituted dihydropyridines via one-pot, four-component reaction of aldehydes, arylamines, dialkyl acetylenedicarboxylate, and malononitrile. The reaction was proceeded at room temperature in the absence of catalyst in aqueous ethyl lactate under visible light irradiation. The main advantages of the present approach are mild reaction condition, high yield, no column chromatography, clean reaction profile, environmentally friendly and sustainable from the economic point of view

Synthesis of Unsymmetrical 1,4-dihydropyridines from Dialkyl Acetylenedicarboxylates, Amines and Arylidenemalononitriles Promoted by Potassium Carbonate

The one-pot, three-component reaction of dialkyl acetylenedicarboxylates, arylamines and arylidenemalononitriles in the presence of potassium carbonate in acetonitrile at 50 °C afforded 11 6-amino-5-cyano-1,4-dihydropyridine-2,3-dicarboxylates, nine of which are novel. These conditions offer simplified operation, easy purification and good yields. Also, this method avoids the use of expensive catalysts, toxic solvents and chromatographic separation.

Ultrasound mediated, green innovation for the synthesis of polysubstituted 1,4-dihydropyridines

An atom efficient protocol via a one-pot four-component cyclocondensation reaction catalyzed by copper(i) iodide in aqueous medium under ultrasonic irradiation has been developed for the synthesis of novel polysubstituted 1,4-dihydropyridines.

A comparative study of the catalytic activity of nanosized oxides in the one-pot synthesis of highly substituted dihydropyridines

A flexible and highly efficient protocol for the synthesis of highly substituted dihydropyridines using nano CeO₂ has been developed.