An efficient one-pot multi component synthesis of polyhydroquinoline derivatives through Hantzsch reaction catalysed by Gadolinium triflate

Quaternary Vanado‐Molybdotungstophosphoric Acid [H5PW6Mo4V2O40] Over Natural Montmorillonite as a Heterogeneous Catalyst for the Synthesis 4H‐Pyran and Polyhydroquinoline Derivatives

“…[62][63][64] Synthesis of polyhydroquinoline derivatives is an interesting research challenge to synthetic chemists. Several improved methods for the synthesis of polyhydroquinoline derivatives such as CoFe 2 O 4 @Pr, [65] molecular iodine, [66] Fe 3 O 4 @chitosan, [67] Thiamine hydrochloride (Vitamin-B 1 ), [68] Amberlite IRA 900, [69] Nano-g-Fe 2 O 3 -SO 3 H, [70] p-toluenesulfonic acids, [71] Sulfamic acids (NH 2 SO 3 H), [72] SiO 2 @Fe 3 O 4 , [73] Gd(OTf) 3 , [74] and Fe 3 O 4 -SA-PPCA [75] have been reported. However, these procedures suffer some drawbacks still exist, such as volatile organic solvents, long reaction time, low yields, expensive catalysts, critical product isolation, and catalyst recycling.…”

A Facile and Catalyst-Free Microwave-Promoted Multicomponent Reaction for the Synthesis of Functionalised 1,4-Dihydropyridines With Superb Selectivity and Yields

“…Recent literature reports show the increasing approval toward the synthesis of 1,4-dihydropyridine moieties through MCR strategy. Some multicomponent reactions have been reported in the literature for the synthesis of different 1,4-dihydropyridine derivatives, which employed catalysts, including sulfamic acid, Fe 3 O 4 /KCC-1/BPAT, Gd(OTf) 3 , aminated CNTs, hydromagnesite, and nano-ZrO 2 -SO 3 H (Rajesh et al, 2013 ; Amoozadeh et al, 2016 ; Sadeghzadeh, 2016 ; Sheik Mansoor et al, 2017 ; Mahinpour et al, 2018 ; da Costa Cabrera et al, 2019 ). In the recent past, different procedures for 1,4-dihydropyridines in good yields have been reported to employ heterogeneous catalysts, such as V 2 O 5 /ZrO 2 (Bhaskaruni et al, 2018 ), USY-zeolit (Alponti et al, 2021 ), and Fe 3 O 4 @SiO 2 (Saffarian et al, 2021 ).…”

Four-Component Fusion Protocol with NiO/ZrO2 as a Robust Recyclable Catalyst for Novel 1,4-Dihydropyridines

“…Due to the vast biological and synthetic importance of 1,4-DHP derivatives, several protocols have been reported via a one-pot strategy and employing different catalysts like nano-tungsten trioxide-supported sulfonic acid (n-WSA), 24 sulfated boric acid nanoparticles, 25 chitosan-supported copper(II) sulfate, 26 Fe 3 O 4 @SiO 2 @Si-(CH 2 ) 3 @melamine-picolineimine@SO 3 H, 27 sulfated polyborate, 28 Fe 3 O 4 /KCC-1/BPAT, 29 chitosan-supported vanadium oxo, 30 magnetic guanidinylated chitosan, 31 nano-ZrO 2 -SO 3 H (n-ZrSA), 32 Gd(OTf) 3 , 33 nicotinic acid, 34 γ-Fe 2 O 3 /Cu@cellulose, 35 SBA-15@AMPD-Co, 36 sulfamic acid, 19 Fe 3 O 4 @D-NH-(CH 2 ) 4 -SO 3 H, 37 Cu-adenine@boehmite, 38 hydromagnesite, 39 Cu(OTf) 2 , 40 ascorbic acid, 41 NS-C 4 (DABCO-SO 3 H) 2 ·4Cl, 42 CBr 4 , 43 and aminated CNTs. 14 Many of these methods either suffer from usage of reflux conditions, lower yields, or long reaction times.…”