3-methyl-1-sulfonic acid imidazolium tetrachloroferrate {[Msim]FeCl4} as an efficient sulfur catalyst was prepared and applied, as an efficient catalyst, for the cross-aldol condensation reaction between cycloalkanones and arylaldehydes to give α,αʹ- bis(arylidene)cycloalkanones in high yields and short reaction times at 75 °C under solvent-free conditions. 3-methyl-1-sulfonic acid imidazolium...

1. Elastins purified by various methods from the ligamentum nuchae and the lungs of cattle of various ages were analysed for amino acid compositions and lysine-derived cross-links. 2. In fully mature elastins from adults the main cross-links were desmosine, isodesmosine and lysinonorleucine and the so-called aldol-condensation product. Trace amounts of merodesmosine were also found. 3. During t...

the catalytic air oxidation-trimerization of alcohols was carried out with hetropolyacids. in the presence of hetropolyacid formation of cyclotrimers of alcohols and aldol condensation products was observed. the 1,3,5-trioxanes were major and aldol condensation compounds were minor products.

Particles in the upper troposphere and lower stratosphere (UT/LS) consist mostly of concentrated sulfuric acid (40-80 wt %) in water. However, airborne measurements have shown that these particles also contain a significant fraction of organic compounds of unknown chemical composition. Acid-catalyzed reactions of carbonyl species are believed to be responsible for significant transfer of gas ph...

 The catalytic air oxidation-trimerization of alcohols was carried out with hetropolyacids. In the presence of hetropolyacid formation of cyclotrimers of alcohols and aldol condensation products ...

conclusions calcined coral/sodium nitrate as a new, efficient, and natural heterogeneous catalyst used in aldol condensation reaction of ketones and aldehydes led to β-hydroxyketones in good to high yields in appropriate condition. materials and methods marine coral (acropora sp.) was washed several times using methanol-ethyl acetate and deionized water and then dried in an oven at 80°c for 48 ...

Alcohol dehydrogenation and condensation reactions are involved in chain growth pathways on Cu/MgCeOx promoted with potassium. These pathways lead to the formation of isobutanol with high selectivity via reactions of higher alcohols with methanol-derived C1 species in reaction steps also relevant to higher alcohol synthesis from CO/H2 mixtures at higher pressures on K–Cu/MgCeOx catalysts. Ethan...

The asymmetric direct aldol condensation of aldehydes with ethyl- and propylketones is catalyzed by syn-alpha-aminoalcohol-Yb(OTf)3 complexes, yielding the anti-1,3-diol monoesters with high diastereocontrol and good enantioselectivity. Three adjacent stereogenic centers are created in a simultaneous aldol condensation and Evans-Tishchenko reduction in an acyclic system.

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...