LaCl3.7H20: An efficient catalyst for one-pot multi-component synthesis of 1,4-polyhydroquinoline derivatives through unsymmetrical Hantzsch reaction (original) (raw)
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Chinese Chemical Letters, 2014
During the past decade, multi-component reactions (MCRs) have become an area of prime interest in synthetic organic chemistry due to their ability in converting more than two components in a single step to complex molecules. MCRs have emerged as efficient, atom economic, time saving and powerful tools in modern synthetic organic chemistry for the synthesis of pharmacologically and biologically important targets as they increase the efficiency of the reaction and avoid the multiple steps along with saving solvents and chemicals. Such reactions allow the formation of new bonds resulting in diverse molecular complexity in a single step [1]. MCRs play a prominent role in modern drug discovery processes [2]. Thus the study of MCRs has become one of the most attractive synthetic strategies preferred by organic chemists in industry and academia. Derivatives of 1,4-dihydropyridine and polyhydroquinoline heterocyclic scaffolds are important classes of well known Ca 2+ channel blockers and constitute the skeletons of drugs used in the treatment of hypertension and cardiovascular diseases [3]. These compounds possess a variety of biological activities including antidiabetic, antitumor, vasodilator, bronchodilator, geroprotective and anti-atherosclerotic properties [4]. They are also explored as antiischemics and in the treatment of Alzheimer's disease [5].
Nafion-H®-catalyzed synthesis of polyhydroquinolines via the Hantzsch multicomponent reaction
Monatshefte für Chemie - Chemical Monthly, 2012
A facile and efficient one-pot, four-component synthesis of polyhydroquinoline derivatives via the Hantzsch reaction using Nafion-H Ò as heterogeneous catalyst in PEG 400-water solvent system is described herein. The present methodology offers several advantages such as excellent yields, simple procedure, shorter reaction times, and milder conditions with remarkable recyclability.
One-step, synthesis of Hantzsch esters and polyhydroquinoline derivatives using new organocatalyst
Chinese Chemical Letters, 2010
À [16], in situ generated HCl [17], K 7 [PW 11 CoO 40 ] [18], metal triflates [19], I 2 [20] silica-supported acids [21,22], ceric ammonium nitrate [23], PTSA-SDS [24], tris(pentafluorophenyl)borane [25] and boronic acids . These methods, however, suffer from drawbacks such as unsatisfactory yields, acidic or basic catalysts,
A Facile and efficient one pot, four component synthesis of polyhydroquinoline derivatives via the Hantzsch condensation reaction using sulphamic acid as heterogeneous catalyst by green approach is described herein. The present methodology offers several advantages such as Excellent yields, economy of cost and time, absence of side products and operational simplicity, ecofriendly, recyclability and reusability of the catalyst are some of the salient features of this reaction.
Journal of Fluorine Chemistry, 2012
A facile and highly efficient one-pot synthesis of polyhydroquinoline derivatives is reported via fourcomponent condensation reaction of aldehydes, b-keto compounds, active methylene compounds and ammonium acetate in the presence of FeF 3 as a catalyst in ethanol at 75-80 8C. The method offers several advantages including high yields, short reaction time, simple work-up procedure and catalyst reusability for several runs. The higher catalytic activity of FeF 3 ascribed due to its high acidity, thermal stability and water tolerance. The superiority of use of FeF 3 to the current process is compared with other Lewis acids, Fe-salts, fluoride sources and insights of the origin of the efficiency are discussed.
ChemCatChem, 2017
We report the synthesis of a new microporous copolymer PPN using triphenylamine and ,-dibromo-p-xylene via Friedel-Crafts alkylation process promoted through anhydrous FeCl3 as an oxidising agent and after the sulfonation of PPN we got sulfonated polymer SPPN having high surface acidity with high BET surface area. We have characterized the PPN and SPPN materials thoroughly by using powder XRD, FT IR, 13 C solid state MAS NMR, FE SEM, HR TEM and N2 sorption techniques. This sulfonated material SPPN has been employed as a heterogeneous, reusable and environmentally benign organic solid acid catalyst for the onepot synthesis of biologically important polyhydroquinoline derivatives under microwave irradiation. Scheme 2. Synthesis of PPN and SPPN.