cellulose was applied as a reusable and green catalyst for the facile four-component synthesis of 6-amino-4-aryl-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile derivatives using hydrazine monohydrate, ethyl acetoacetate, malononitrile and aryl aldehydes, under solvent-free and thermal conditions. the use of non-toxic and inexpensive catalyst, short reaction time, clean work-up and goo...

The biaryl structural motif is a predominant feature in many pharmaceutically relevant and biologically active compounds. As a result, for over a century1 organic chemists have sought to develop new and more efficient aryl-aryl bond-forming methods. Although there exist a variety of routes for the construction of aryl-aryl bonds, arguably the most common method is through the use of transition-...

Polyvinyl alcohol (PVA)-based films containing Chinese bayberry tannin (BT) were prepared by cross-linking using glyoxal, glutaraldehyde and dialdehyde starch, individually. The presence of cross-linkers was evident to promote the transparency decrease moisture content PVA/BT films, while water solubility stayed almost unchanged in cross-linked films. All provided promotion vapor permeability, ...

nano-graphene oxide was synthesized by the oxidation of graphite powders. the structural nature of the nano-graphene oxide was characterized by a variety of techniques including xrd, tem, ft-ir and uv/vis. the functional groups on its basal planes and edges of nano-grahene oxide play important role in catalytic activity. the catalytic activity of nano-graphene oxide was investigated on crossed-...

An efficient catalytic asymmetric hetero-ene reaction of 5-methyleneoxazolines with 1,2-dicarbonyl compounds (including α-ketoesters and glyoxal derivatives) was realized using Ni(II)-N,N'-dioxide complexes as the catalysts. It provides a rapid, high yielding (up to 99%) route for the preparation of 2,5-disubstituted oxazole derivatives in a highly enantioenriched form (up to >99% ee) under mil...

Density functional theory calculations demonstrate that Al(III)-catalyzed conversion of glyoxal to glycolic acid proceeds via a 7-membered dual Lewis acid-hydrogen bonding activation transition state of the 1,2-hydride shift, rather than the previously proposed 5-membered metal-alkoxide chelate activation transition state.