Molecular iodine-catalyzed one-pot synthesis of 4-substituted-1,4-dihydropyridine derivatives via Hantzsch reaction

Molecular iodine-catalyzed one-pot synthesis of some new Hantzsch 1,4-dihydropyridines at ambient temperature

“…In the present work, based on a literature survey, 38 30 mol% of catalyst was used throughout the experiments. One equiv.…”

“…It has been used as a mild Lewis acid in the dehydration of tertiary alcohols to alkenes, in the formation of ethers, as well as β-keto enol ethers, [32][33][34] for esterification, 35 transesterification, 36 acetylation 29 and benzothiophene 37 formation, but there are only a few reports about its use for the synthesis of 1,4-DHPs. 38,39 Therefore, we decided to synthesize some new symmetrical, unsymmetrical and N-substituted 1,4-DHPs promoted by a catalytic amount of iodine under ambient conditions with good to excellent yields.…”

A simple and efficient approach for synthesis of 1,4-dihydro-pyridines using nano-crystalline solid acid catalyst

“…However, the yield of 1,4-DHP obtained by Hantzsch method is generally low [13][14][15]. Various methods for the synthesis of dihydropyridine derivatives are described in the literature including condensation of aromatic aldehydes, β-dicarbonyl compounds and ammonium acetate using of microwave [16], ionic liquids [17], tetrabutylammonium hydrogen sulfate [18], silica gel/NaHSO 4 [19], AlCl 3 .6H 2 O [20], TMSI [21], triphenylphosphine [22], InCl 3 [23], I 2 [24], cellulose sulfuric acid [25], alumina sulfuric acid [26], SiO 2 /HClO 4 [27], metal triflate [28], Fe(CF 3 CO 2 ) 3 [29], nano CuO [30], nano MgO [31], ultrasound irradiation [32], solvent free [33], and aqueous media [34].…”

Carbon-Based Solid Acid Catalyzed Synthesis of Polyhydroquinoline Derivatives via Hantzsch Reaction Under Solvent-Free Conditions

“…Recently, a number of improved methods have been reported in the literature for the synthesis of polyhydroquinolines which involve the use of microwave irradiation 12 , solar thermal energy 13 , grinding 14 , and also using various catalysts such as ionic liquid 15 , metal triflates 16 , HY-Zeolite 17 , montmorillonite K-10 18 , cerium(IV) ammonium nitrate 19 , HClO 4 -SiO 2 20 , molecular iodine 21 , Yb(OTf) 3 …”