N‐rich Porous Organic Polymer as Heterogeneous Organocatalyst for the One‐Pot Synthesis of Polyhydroquinoline Derivatives through the Hantzsch Condensation Reaction

Abstract

Incorporation of nitrogen functionality onto the high surface area porous polymeric network are very demanding in designing suitable heterogeneous organocatalyst having surface basicity. Here we report the synthesis of a new N‐rich triazine based microporous organic polymer (TrzMOP) through a simple and efficient condensation pathway involving the reaction between 1,4‐bis(4,6‐diamino‐s‐triazin‐2‐yl)‐benzene (SL‐1) and 2,5‐thiophene dicarboxaldehyde. The material has been characterized by using powder XRD, FTIR spectroscopy, solid state magic‐angle spinning 13C NMR, CHN analysis, FESEM, HRTEM, CO2‐TPD and N2 adsorption/desorption techniques. This nitrogen‐rich new porous organic polymer showed very high catalytic efficiency for one‐pot proficient synthesis of polyhydroquinoline derivatives via microwave assisted condensation reaction. As little as 8 mg of catalyst was found to be effective under the optimum reaction conditions. In addition, TrzMOP catalyzed synthesis of biologically active polyhydroquinoline derivatives are very cost effective, scalable, less time consuming, and environmentally benign compared to those of currently used as heterogeneous catalysts.

Solvent‐Free Hantzsch Condensation Reaction Leading to Polyhydroquinoline and 1,8‐Dioxo‐decahydroacridine Derivatives Promoted by Nanosized Kaolin‐[BTMSP]‐NH2+ HSO4−

“…However, this classic process suffers from several disadvantages, such as long reaction time, use of a large quantity of volatile organic solvents and low yield. [1,9] Since then, a large number of catalysts such as Fe 3 O 4 -adenine-Ni, [10] L-proline, [11,12] ED/MIL-101(Cr), [13] molecular iodine, [14] Yb-(OTf) 3 , [15] ceric Ammonium Nitrate, [16] K 7 [PW 11 CoO 40 ], [17] ZnO, [18] glycine, [19] PPA-SiO 2 , [20] FeF 3 , [21] Cd(NO 3 ) 2 .4H 2 O, [22] polyethylene glycol, [23] ChCl/urea, [24] nano-γ-Fe 2 O 3 -SO 3 H, [25] IRMOF-3, [4] Ga 2 O 3, [26] SBA-15@AMPDÀ Co, [27] nicotinic acid, [28] Nidithizone@boehmite, [29] TEDETA@BNPs, [30] ascorbic acid, [31] La 3 + / 4A, [32] Fe 3 O 4 @B-MCM-41, [33] and BiBr 3 [34] have been used to improve the Hantzsch reaction conditions. Although each of the reported catalysts and techniques has its advantages, nevertheless further efforts are needed to introduce more efficient and cleaner catalytic systems for the synthesis of the above mentioned important target molecules.…”

“…The preparation of 1,4‐DHPs was first reported by Arthur Hantzsch in 1882 through a one‐pot condensation of aldehydes, β ‐ketoesters, and ammonia in acetic acid or ethanol. However, this classic process suffers from several disadvantages, such as long reaction time, use of a large quantity of volatile organic solvents and low yield [1,9] . Since then, a large number of catalysts such as Fe 3 O 4 ‐adenine‐Ni, [10] L ‐proline, [11,12] ED/MIL‐101(Cr), [13] molecular iodine, [14] Yb(OTf) 3 , [15] ceric Ammonium Nitrate, [16] K 7 [PW 11 CoO 40 ], [17] ZnO, [18] glycine, [19] PPA‐SiO 2 , [20] FeF 3 , [21] Cd(NO 3 ) 2 .4H 2 O, [22] polyethylene glycol, [23] ChCl/urea, [24] nano‐γ‐Fe 2 O 3 ‐SO 3 H, [25] IRMOF‐3, [4] Ga 2 O 3, [26] SBA‐15@AMPD−Co, [27] nicotinic acid, [28] Ni‐dithizone@boehmite, [29] TEDETA@BNPs, [30] ascorbic acid, [31] La 3+/ 4A, [32] Fe 3 O 4 @B‐MCM‐41, [33] and BiBr 3 [34] have been used to improve the Hantzsch reaction conditions.…”

“…MCRs mostly are able to reduce the reaction time, cost, and waste generation. [1][2][3] 1,4-Dihydropyridines (1,4-DHPs), which can be prepared through multi-component reactions, are a valuable class of heterocyclic scaffolds exhibiting a wide range of biological and pharmaceutical activities such as calcium channel blocking, antidiabetic, anticancer, antibacterial, antimalarial, antiplasmodial, and anti-HIV-1 protease. [4][5][6][7] Some biologically active 1,4-DHPs are shown in Figure 1.…”

A new silver coordination polymer based on 4,6-diamino-2-pyrimidinethiol: synthesis, characterization and catalytic application in asymmetric Hantzsch synthesis of polyhydroquinolines

“…In this sense, the coordination polymers have caught the attention as catalytic systems for many heterogeneous industrial reactions 14 – 19 . These types of heterogeneous catalysts are attractive due to their structural ordering, large size and volume of pores, and large specific surface area 20 – 23 . Furthermore, when compared to conventional mesostructured silica-based supports, the CPs ones have shown much higher activity and selectivity by providing good and regular interaction between metal species and organic reagents 24 , 25 .…”

Pd(0)‐guanidine@MCM‐41: a very effective catalyst for rapid production of bis (pyrazolyl)methanes

“…Environmental friendly operation via reducing the number of synthetic steps and work up, the energy consumption, reaction time, waste production, and eliminating the isolation of unstable intermediates are among the advantages of MCRs . Over the last few decades, with increasing environmental concerns, the design of new MCRs with ecofriendly, green procedures have become increasingly useful tools, especially in the fields of drug discovery, organic synthesis and material science . Because of the increasing concern of the harmful effects of organic solvents on the environment and human body, organic reactions that are operated with green solvents or without conventional organic solvents have aroused the attention of organic and medicinal chemists .…”