Novel and Effective Strategy of Multifunctional Titanium Incorporated Mesoporous Material Supported Ionic Liquid Mediated Reusable Hantzsch Reaction

Abstract

Mesoporous material supported functionalized ionic liquids have been designed and synthesized, characterized and evaluated as novel heterogeneous catalysts for the Hantzsch reaction. The as-fabricated catalysts show good performance in the Hantzsch synthesis of 1,4-dihydropyridines under ambient conditions, especially the titanium incorporated mesoporous material supported ionic liquid Ti-SBA-15@IL-BF 4 , based on a synergetic effect of titanium site of mesoporous material carrier and the acidic sites of ionic liquid. In addition, the heterogeneous catalyst offers simple operation for recovery and the recycling test showed that it could be reused for five times without significant loss of catalytic activity.

Recent Progresses in the Multicomponent Synthesis of Dihydropyridines by Applying Sustainable Catalysts Under Green Conditions

“…Tan and his colleagues (Tan et al, 2019) have formulated a technique for incorporating titanium into a mesoporous material to catalyse Hantzsch reaction mediated by an ionic liquid (Scheme 25). The tailored catalyst Ti-SBA-15@IL-BF 4 was used to form 1,4-dihydropyridine derivatives (73) which showed high yielding capacity and sustained its catalytic ability even after running for five consequent cycles.…”

Similarity and Competition between Biginelli and Hantzsch Reactions: an Opportunity for Modern Medicinal Chemistry

“…The diffusion of the Hantzsch reaction in building up the 1,4-DHPs libraries is mainly to be attributed to the discovery that ammonia could be efficiently replaced by ammonium acetate. [30,31] Furthermore, the use of several different homogeneous and heterogeneous catalysts, [32] as well as ionic liquids, [33] organocatalysts [34,35] and alternative energy sources, [35][36][37][38][39] can accelerate the reaction times and increase the reaction yields. Several past reviews provide a complete survey on the synthetic methodologies for realizing the Hantzsch reaction, as well as on the libraries of the resulting structurally different 1,4-DHPs.…”

Piperazinium Nano Silica Sulfonate: An Efficient Catalyst for the Hantzsch Reaction

“…Because of their above mentioned importance numerous reagents have been reported for the acceleration of the synthesis of dihydropyridine and polyhydroquinoline derivatives which of them palladium (0) nanoparticles, [16] K 7 [PW 11 CoO 40 ], [17] p-TSA, [18] Cs 2.5 H 0.5 PW 12 O 40 , [19] ionic liquids, [20,21] ceric ammonium nitrate (CAN), [22] Hf(NPf 2 ) 4 , [23] polymer, [24] HYzeolite, [25] BINOL-phosphoric acid derivatives, [26] HClO 4 ⋅ SiO 2 , [27] alumina sulfuric acid (ASA), [28] Yb(OTf) 3 , [29] Sc(OTf) 3 , [30] Bi-(NO 3 ) 3 ⋅ 5H 2 O, [31] nickel nanoparticle, [32] MgO nanoparticles, [33] Zn-VCO 3 hydrotalcite [34] and La 2 O 3 [35] are examples. Although these procedures caused a great extent of improvement, but most of them suffer from drawbacks such as need to use of stoichiometric amounts of reagents or metal precursors, unsatisfactory product yields, use of volatile organic solvents, harsh reaction conditions, non-recoverability of the catalyst, tiresome work-up and moisture sensitivity.…”