Metal-Free Multicomponent Syntheses of Pyridines

Zirconium Metal‐Organic Framework (UiO‐66) as a Robust Catalyst toward Solvent‐Free Synthesis of Remarkable Heterocyclic Rings

“…Due to the high importance of pyridines heterocyclic compounds in organic and medicinal chemistry, several synthetic routes have been reported for the synthesis of pyridine scaffolds . To investigate the generality and utility of this catalytic system, we further examine the efficiency of using of UiO‐66 catalyst for the synthesis 2,4,6‐triphenyl pyridines by pseudo four‐component reaction of acetophenone, benzaldehyde and ammonium acetate under solvent‐free conditions.…”

2,3‐Dichloro‐5,6‐Dicyano‐1,4‐Benzoquinone (DDQ)‐Mediated Tandem Oxidative Coupling/Intramolecular Annulation/Dehydro‐Aromatization for the Synthesis of Polysubstituted and Fused Pyridines

“…[2] As a consequence, considerable efforts have been devoted to developing efficient approaches for the preparation of pyridines. [6] During the past few decades, a large number of alternative strategies for preparing pyridines have been successfully established such as metal-mediated cycloaddition, [7] metal-free multicomponent reaction, [8] transition-metal-catalyzed coupling of ketoxime acetates, [9] ring-expansion reaction, [10] and so on. [6] During the past few decades, a large number of alternative strategies for preparing pyridines have been successfully established such as metal-mediated cycloaddition, [7] metal-free multicomponent reaction, [8] transition-metal-catalyzed coupling of ketoxime acetates, [9] ring-expansion reaction, [10] and so on.…”

“…Then, various solvents such as 1,4-dioxane, THF, CHCl 3 , CH 2 Cl 2 , CH 3 NO 2 , CH 3 CN, and DMSO were conducted (entries [2][3][4][5][6][7][8]. It showed that 1,4-dioxane was the best option (entry 2).…”

Organocatalytic clean synthesis of densely functionalized 4H-pyrans by bifunctional tetraethylammonium 2-(carbamoyl)benzoate using ball milling technique under mild conditions

“…Although the impact of transition-metal-based catalysts on chemical synthesis cannot be completely understated, some metal-based systems can be expensive, toxic, and sensitive to air or moisture (38)(39)(40). Hence, the advent of organocatalysis brought the prospect of a complementary mode of catalysis, with the potential for savings in cost, time and energy, an easier experimental procedure, and reductions in chemical waste (41)(42)(43)(44)(45).…”