various types of aldehydes undergo crossed-aldol condensation with ketones in the presence of melamine trisulfonic acid (mtsa) under solvent-free conditions. the reported method is mild, efficient and has the advantages such as using heterogeneous catalysis, short reaction times, high yields of the products and the recyclability of the catalyst.

Various types of aldehydes undergo crossed-Aldol condensation with ketones in the presence of melamine trisulfonic acid (MTSA) under solvent-free conditions. The reported method is mild, efficient and has the advantages such as using heterogeneous catalysis, short reaction times, high yields of the products and the recyclability of the catalyst.

Various types of aldehydes undergo crossed-Aldol condensation with ketones in the presence of melamine trisulfonic acid (MTSA) under solvent-free conditions. The reported method is mild, efficient and has the advantages such as using heterogeneous catalysis, short reaction times, high yields of the products and the recyclability of the catalyst.

A new method for enolate generation via the gold-catalyzed addition of boronic acids to alkynes is reported. The formation of boron enolates from readily accessible ortho-alkynylbenzeneboronic acids proceeds rapidly with 2 mol % PPh(3)AuNTf(2) at ambient temperature. The enolates undergo aldol reaction with an aldehyde present in the reaction mixture to give cyclic boronate esters, which can be...

The direct aldol-type condensation of aldehydes with ethyl diazoacetate catalyzed by the chiral complex of BINOL derivatives-Zr(O(t)Bu)(4) gave beta-hydroxy alpha-diazo carbonyl compounds with moderate enantioselectivities (53-87% ee). [reaction: see text]

Aldol reactions belong to the most frequently used C-C bond forming transformations utilized particularly for the construction of complex structures. The selectivity of these reactions depends on the geometry of the intermediate enolates. Here, we have reacted octyl pentafluoro-λ6-sulfanylacetate with substituted benzaldehydes and acetaldehyde under the conditions of the silicon-mediated Mukaiy...

The self-condensation of alkynals was for the first time implemented under mild organocatalytic conditions and was successfully linked with a domino organocatalytic inverse-electron-demand oxa-Diels-Alder reaction, which led to the development of a facile one-pot method to produce a wide variety of polysubstituted chiral 3,4-dihydropyrans with good to high yields and diastereoselectivities and ...

Biomass has the potential to serve as a sustainable source of energy and organic carbon for our industrialized society. The focus of this Review is to present an overview of chemical catalytic transformations of biomass-derived oxygenated feedstocks (primarily sugars and sugar-alcohols) in the liquid phase to value-added chemicals and fuels, with specific examples emphasizing the development of...

Divergent synthesis of indoles, oxindoles, isocoumarins and isoquinolinones is described in this report by using a general Pd-catalyzed tandem reaction of β-hydroxy carbonyl compounds with aryl halides bearing an ortho-nitro, -ester or -cyano substituent. A key retro-aldol/α-arylation reaction is involved that merges classic Pd cross-coupling chemistry with novel Pd-promoted retro-aldol C-C act...