A series of phenyl sulfonate metal coordination polymers as catalysts for one-pot Biginelli reactions under solvent-free conditions

Abstract

Three new metal coordination polymers, namely, [Co(DPP)2(H2O)2]·(BS)2·2H2O (1), [Co(DPP)2(H2O)2]·(ABS)2·2H2O (2) and [Co(DPP)2(MBS)2] (3) [DPP = 1,3-di(pyridin-4-yl)propane, BS = phenyl sulfonic acid, ABS = p-aminobenzene sulfonic acid, MBS = p-methylbenzene sulfonic acid] were obtained under hydrothermal conditions. Complexes 1-3 were structurally characterized using X-ray single-crystal diffraction, XRD and IR spectroscopy. Both complexes 1 and 2 display a 1D tape structure. Meanwhile, complex 3 exhibits a 2D layer and further stacks via C-Hπ interactions to generate a three-dimensional supramolecular architecture. These three metal coordination polymers have been applied as catalysts for the green synthesis of a variety of 3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions through the Biginelli reaction. Interestingly, the catalysis products have been obtained in high yields under eco-friendly synthesis conditions.

A Set of phenyl sulfonate metal coordination complexes triggered Biginelli reaction for the high efficient synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones under solvent‐free conditions

“…Hence, the optimized solvent was found to be solvent‐free for the preparation of dihydropyrimidinones, which is considered to avoid the use of any organic solvents, to protect the environment, and to be benign pathway to sustainability. In an addition, the use of solvent‐free was in line with the green chemistry …”

“…Many catalytic systems have been performed for the synthesis of DHPMs through the Biginelli reaction, including Lewis acid, BrØnsted acid, and organic bases such as L ‐tyrosine, Phatic acid, PPh 3 , β ‐Cyclodextrin, L ‐proline derivatives, Cobalt (II)‐phthalocyanine, Li (glycine)(CF 3 SO 3 ), TiO 2 ‐MWCNTs, Ionic liquid, SiO 2 ‐CuCl 2 , ZAF‐16 and PPF‐SO 3 H . Additionally, some other techniques for the synthesis of DHPMs have also been employed in the Biginelli condensation reaction, for instance, ionic liquid, solvent‐free, solid‐state synthesis, ultrasound and microwave . Recently, IRMOF‐3 and Cd‐based MCCs were successfully employed in the synthesis of DHPMs with good yields .…”

Biginelli Reaction: Polymer Supported Catalytic Approaches

“…The Biginelli mixture and MCPs catalyst were heated under solvent-free conditions and afforded high to excellent yields of DHPMs. Among three MCPs, [Co­(DPP) 2 (H 2 O) 2 ]·(ABS) 2 ·2H 2 O found comparatively less efficient than others . The article elucidated efficacy of MCPs as a catalyst for the Biginelli reaction with short reaction time and excellent yields.…”

“…Among three MCPs, [Co-(DPP) 2 (H 2 O) 2 ]•(ABS) 2 •2H 2 O found comparatively less efficient than others. 174 The article elucidated efficacy of MCPs as a catalyst for the Biginelli reaction with short reaction time and excellent yields. The investigation of MCPs as a catalyst with detail study contributed the impactful outfit for the advancements in the Biginelli reaction.…”

Mixed cobalt/nickel metal–organic framework, an efficient catalyst for one-pot synthesis of substituted imidazoles

“…Several MOFs have been employed as solid catalyst or catalyst supports for a variety of organic reactions. These include oxidation [16], Friedel-Crafts [17], Biginelli [18], Sonogashira [19], Knoevenagel condensation [20], Henry [21], Friedlander [22], and cyclization reactions [23].…”