89809-89-2

A novel bridgehead azocine 4 has been obtained from aminopyran 1 and benzylidinemalononitrile 6. The structure of 4 was confirmed by X-ray diffraction.

The syntheses, X-ray structural investigations and calculations of the conformational preferences of the carbonyl substituent with respect to the pyran ring have been carried out for the two title compounds, viz. C 15H14N2

Abstract: The green and nano catalyst was simply prepared through the reaction of ferric sulfasalazine with nanomaterial CoFe2O4-cellulose as a magnetic biopolymer surface. This novel heterogeneous organometallic catalyst was charact

Immobilized piperazine on the surface of graphene oxide (piperazine-GO) is synthesized and characterized by different methods such as FT-IR, solid-state 29Si{1H} and 13C{1H} CP/MAS NMR, elemental analysis, TGA, TEM, FE-SEM, XPS, and TPD. Subsequently, it is used as a heterogeneous bifunctional acid-base catalyst for the efficient multicomponent reaction of malononitrile, different active compounds containing enolizable C-H bonds and various aryl/alkyl aldehydes in aqueous ethanol. A wide variety of 2-amino-3-cyano-4H-chromenes are synthesized in the presence of this heterogeneous catalyst in good to high yields and with short reaction times. The catalyst is easily separated and reused for at least six times without significant loss of activity. The acidic nature of GO improves the catalytic activity of the supported piperazine and also provides heterogeneity to the catalyst. Use of aqueous ethanol as a green solvent, high turnover numbers (TON), facile catalyst recovery and reuse, simple work-up and generality of the method make this protocol an environmentally benign procedure for the synthesis of the title heterocycles.

A simple, effective and ecofriendly biocatalytic method has been developed to construct 2-amino-4H-pyrans via tandem multi-component reaction (MCR) of aldehyde, malononitrile and ethyl acetoacetate in one pot. The catalytic activity of lipases in differen

Clean, practical, and efficient electrochemical synthesis of pharmaceutically relevant 4H-pyran derivatives by one-pot three-component combination of an aryl aldehyde, malononitrile, and a dicarbonyl compoundis developed. The synthesis is performed in eth

The invention discloses a synthesis method of 2-amino-4H-pyran and a derivative of the 2-amino-4H-pyran. According to the method, candida rugosa lipase (CRL) is adopted as a catalyst to initiate a tandem MCR reaction, and 2-amino-4H-pyran is synthesized i

The discovery of a new L-valine promoted facile and versatile green synthesis of diversified 2-amino-3-cyano-4H-pyrans using a one pot multicomponent-tandem reaction of aromatic aldehydes, malononitrile, and diverse electron-rich enolizable carbonyl compo

A high-yielding, practical, efficient, and environmentally benign one-pot multicomponent synthesis of functionalized 2-amino-4 H -pyrans from β-dicarbonyl compounds, malononitrile, and aldehydes is presented. Good to excellent yields were obtained under m

Abstract: The complex catalyst of [ZnClO.urea]?[Ch.urea]+ has been prepared by dissolving of nanoZnO in choline chloride:2urea at 50 °C. The concentration of [ZnClO.urea]? in the given liquid is 19,987 ppm and 10.5 times h

A simple, catalyst free, water mediated, one pot four component, green protocol was developed for title compounds 7 starting from aromatic aldehydes (1), malononitrile (2), 1,3-diones (3) and N-chlorosuccinimide (NCS) in a sequential addition reaction at

An efficient one-pot synthesis of functionalized 2-amino-4H-pyrans by a meglumine-catalyzed three-component reaction has been developed. A broad range of substrates including aromatic and heteroaromatic aldehydes, isatin derivatives, and acenaphthenequino

An ecofriendly one-pot multicomponent reaction of 1,3-dicarbonyl compounds, aldehydes, and malononitrile was carried out in a different deep eutectic solvent (DES) based on choline chloride, to synthesize highly functionalized benzopyran and pyran derivat

A green and highly efficient protocol has been developed for the synthesis of 4H-pyran scaffolds installing a one-pot three-component coupling reaction of an aldehyde, malononitrile, and a 1,3-diketo compound using nano structured ZnO as the catalyst in a

The multicomponent reaction (MCR) of aromatic aldehydes 1 and malononitrile (2) with active methylenes 5a-h in the presence of L-proline produced pyrans and thiopyrans 6a-h stereospecifically and in good yields. Moreover a novel MCR of ethyl propiolate (8) with 1 and 2 in the presence of L-proline to afford (R)-polysubstituted pyran is also reported. X-ray structures, e.e. and optical activity of the synthesized compounds indicated that L-proline as a catalyst is responsible for the observed enantioselectivity in the studied reactions.

Baker's yeast catalyzed one-pot three-component cyclocondensation of aryl aldehydes, malononitrile, and b-dicarbonyls in organic medium has been carried out to obtain polyfunctionalized 4H-pyrans. The reaction has been carried out at room temperature in o

Palladium on carbon (10 % Pd/C) efficiently catalyzes the (retro-)Michael addition of activated methylene compounds 2a-d, such as malononitrile (2b), to mono- and doubly activated styrenes 1a-h to give the adducts 3a-l. The scope and limitations are described. The Knoevenagel condensation reaction of benzaldehyde and 2b or ethyl cyanoacetate (2c) is also catalyzed by 10 % Pd/C. In these cases the Michael adducts can even be prepared in a three-component reaction. A mechanism, with as first step the oxidative addition of 2a-d to Pd0, is proposed. Palladium on carbon (10 % Pd catalyzes the (retro-)Michael addition of activated methylene compounds 2a-d to mono- anddoubly activated styrenes. The scope and limitations of the reaction are described. A mechanism is proposed. Copyright

HETEROGENEOUS ecofriendly base catalysis namely, chitosan and nanoparticulated MgO are promising new catalysis in Michael addition that can efficiency replace homogeneous polluting catalysts. Aminopyrancarbonitriles, pyranopyrazole, thiazolopyridines and chromenes can be obtained in ethanolic or methanolic chitosan or MgO in good yields.

A clean and efficient method for the synthesis of 4H-pyran derivatives through the one-pot condensation of aromatic aldehydes, malononitriles, and β-dicarbonyl compounds, using guanidine base tetramethylguanidine in [bmim] [BF4] ionic liquid as

An efficient single-pot method for the synthesis of polyfunctionalized 4H-pyrans using alkaline metal fluoride as a catalyst is described.

The nitriles I reacted with acetylacetone and with ethyl acetoacetate to afford 2-amino-3-cyano-4H-pyran derivatives.They reacted further to yield pyranopyridine derivatives.The reaction of V with acetylacetone afforded the pyridinethione VIII.This afford

A novel one step synthesis of pyranopyridines from malononitrile and unsaturated ketones is reported.The reaction mechanism is discussed and takes place through an intermediate monocyclic 4H-pyran.Several derivatives with different substitution pat

The behaviour of several 2-amino-3-cyano-4H-pyran derivatives toward a variety of nucleophilic reagents is reported.

The reaction of cinnamonitriles with acetylacetone end ethyl acetoacetate is reported.Several new polyfunctional pyrans could be prepared.Spectral data of the synthesized products is reported.

The cyclization of the ketonitriles obtained from the reaction of suitably substituted propenones with propanedinitrile leads to alkyl substituted 4H-pyrans.Some of the starting propenones had to be prepared by base promoted opening of an isoxazole ring in the presence of an aldehyde.An exception to the general synthesis is also reported.