Enantioselective synthesis of 2-amino-4H-pyrans via the organocatalytic cascade reaction of malononitrile and α-substituted chalcones

tert-Butyl 2-Amino-3-cyano-5-oxo-4-phenyl-5,7-dihydropyrano[2,3-c]pyrrole-6(4H)-carboxylate

Organocatalyzed synthesis of tert-butyl 2-amino-3-cyano-5-oxo-4-phenyl-5,7-dihydropyrano[2,3-c]pyrrole-6(4H)-carboxylate, prepared from Boc-tetramic acid and benzylidenemalononitrile, is disclosed. Two bifunctional noncovalent organocatalysts were employed, yielding the product as a racemic mixture in both cases. The structure of the new synthesized compound was confirmed by high resolution mass-spectrometry, 1H- and 13C-NMR, HSQC, and IR spectroscopy.

Exploration of chalcones and related heterocycle compounds as ligands of adenosine receptors: therapeutics development

Adenosine receptors (ARs) are ubiquitously distributed throughout the mammalian body where they are involved in an extensive list of physiological and pathological processes that scientists have only begun to decipher. Resultantly, AR agonists and antagonists have been the focus of multiple drug design and development programmes within the past few decades. Considered to be a privileged scaffold in medicinal chemistry, the chalcone framework has attracted a substantial amount of interest in this regard. Due to the potential liabilities associated with its structure, however, it has become necessary to explore other potentially promising compounds, such as heterocycles, which have successfully been obtained from chalcone precursors in the past. This review aims to summarise the emerging therapeutic importance of adenosine receptors and their ligands, especially in the central nervous system (CNS), while highlighting chalcone and heterocyclic derivatives as promising AR ligand lead compounds.

Synthesis and photophysical and mechanochromic properties of novel 2,3,4,6-tetraaryl-4H-pyran derivatives

The crystallization abilities caused by introducing different aromatic groups were found to play a very important role in determining the formation of the mechanochromic activities of 2,3,4,6-tetraaryl-4H-pyran derivatives.

Synthesis of Benzothiophene-Fused Pyran Derivatives via Piperidine Promoted Domino Reaction

A new domino reaction between thioaurones and malononitrile has been reported. This reaction allows efficient access to benzothiophene-fused pyran derivatives in good yields under mild reaction conditions. The substrate scope is broad; a series of benzothiophene-fused pyran derivatives have been synthesized.

A dynamic kinetic asymmetric transfer hydrogenation–cyclization tandem reaction: an easy access to chiral 3,4-dihydro-2H-pyran-carbonitriles

A catalytic enantioselective dynamic kinetic asymmetric transfer hydrogenation–cyclization tandem reaction is developed for 1,3-difunctionalized racemic ketones.

Asymmetric Inverse-Electron-Demand Oxa-Diels-Alder Reaction of Allylic Ketones through Dienamine Catalysis

A remote β,γ-regioselective asymmetric inverse-electron-demand oxa-Diels-Alder reaction between allylic ketones and α-cyano-α,β-unsaturated ketones has been developed through induced extended dienamine catalysis of a cinchona-derived primary amine. A spectrum of densely substituted dihydropyran frameworks were efficiently produced with excellent enantioselectivity and fair to exclusive diastereoselectivity.

Quinine catalysed asymmetric Michael additions in a sustainable solvent

Diethyl carbonate is shown to be a suitable, sustainable solvent in which to carry out quinine catalysed asymmetric Michael additions of malononitriles to enones.

Synthesis and anti-cancer evaluation of steroidal diglycoside–pyrazoline hybrids

A new series of pyrazoline-steroidal diglycoside hybrids were synthesized via catalyzed cyclocondensation of the corresponding chalcones, screened for in vitro cytotoxic activity and the SAR deduced.