An efficient, multicomponent approach for solvent-free synthesis of 2-amino-4H-chromene scaffold

Abstract

Solvent-free one-pot synthesis of 2-amino-4H-chromene scaffold is described in a very simple, efficient, and environmentally benign method using sodium carbonate as a cheap and non-toxic catalyst with up to excellent yields.

Efficient tandem synthesis of a variety of pyran-annulated heterocycles, 3,4-disubstituted isoxazol-5(4H)-ones, and α,β-unsaturated nitriles catalyzed by potassium hydrogen phthalate in water

“…Several synthetic methods have been widely applied for synthesis of pyran-based heterocyclic compounds, using many homogeneous or heterogeneous organic, inorganic, and nanomaterial catalysts, for example hexamethylenetetramine (HMT) [40], heteropolyacid [41], diammonium hydrogen phosphate [42], DBU [43], piperidine [44][45][46][47], tetrabutylammonium bromide (TBAB) [48], ionic liquids [49], morpholine [50], 4-(dimethylamino)pyridine (DMAP) [51], urea [52], 3-hydroxypropanaminium acetate (HPAA) [53], N-propylpiperazine sodium n-propionate (SBPPSP) [54], silica gel [55], sulfonic acid-functionalized silica [ [60], meglumine [61], I 2 /K 2 CO 3 [62], cetyltrimethylammonium bromide (CTABr) [63], nano-sized MgO [64], nano-structured Na 2 CaP 2 O 7 [65], NaHCO 3 [66], Na 2 CO 3 [67], triazine-functionalized ordered mesoporous organosilica [68], potassium phosphate tribasic trihydrate [69], Mg/Al hydrotalcite [70], Amberlyst A21 [71], DABCO [72], CeO 2 /CaO nanocomposite oxide [73], triton B [74], tetrabutylammonium chloride (TBAC) [75], nano-eggshell powder [76], basic alumina [77], [bmim]OH [78,79], LiBr [80], glycine [81], silica nanoparticles [82], ionic liquid choline chlorid...…”

An Expeditious and Green Approach for the Synthesis of 2-Amino-4h-Chromenes Using a Catalyst of Natural Origin

“…6-8. Some among them are extremely effective against such kind of diseases which influenced by nitrogen-activated protein kinase enzyme inhibitors. Some of them have antimicrobial activity , 11 cytotoxic effect against human cancer cells, 12 antiallergic activity, 13 central nervous system influencing activity, 14 antiproliferation activty. 15 Several derivatives are also widely used as agrochemicals, 16 antioxidant 17 and antiinflammatory agent.…”

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

“…Indeed, malononitrile has been used as a nucleophile in organic synthesis (48). A literature survey shows that several modified methods have been reported using different catalysts such as tungstic acid functionalized mesoporous SBA-15 (49) (66,67), and chitosan (68). However, some of these protocols require highly corrosive, fuming or expensive catalysts, odorous amines, high temperatures using volatile or toxic solvents, long reaction times, multi-step preparation of the catalysts, troublesome waste discarding, and affordable products with only Scheme 3.…”