Aliphatic and aromatic aldehydes were converted into the corresponding pinacoles by using different cerium catalysts. Ce(OtBu)3 proved to be superior over other cerium(III) catalysts. Especially the highly diastereoselective pinacol coupling of sterically non demanding aldehydes such as hexanal is remarkable.

Novel chiral bis(oxazoline) ligands bearing dibenzo[a,c]cycloheptadiene and a dihydroxy group have been synthesized and their application in the catalytic asymmetric addition of diethylzinc to aldehydes investigated. The enantioselectivities for the aromatic aldehydes are generally high and up to 96% ee was obtained. 2003 Elsevier Ltd. All rights reserved.

It was found that 1,2-trifluoromethylation reactions of ketones, enones, and aldehydes were easily accomplished using the Prakash reagent in the presence of catalytic amounts of cesium carbonate, which represents an experimentally convenient, atom-economic process for this anionic trifluoromethylation of non-enolisable aldehydes and ketones.

The Schmidt reaction of aromatic aldehydes using a substoichiometric amount (40 mol %) of triflic acid is described. Low catalyst loading was enabled by a strong hydrogen-bond-donating solvent hexafluoro-2-propanol (HFIP). This improved protocol tolerates a broad scope of aldehydes with diverse functional groups and the corresponding nitriles were obtained in good to high yields without the nee...

The first Lewis acid-catalyzed trifluoromethylation reactions of aldehydes with Me3SiCF3 under TiF4/DMF, Ti(O iPr)4/DMF and Cu(OAc)2/dppp/toluene conditions are described. We have successfully applied this methodology to the difluoromethylation of aldehydes using Me3SiCF2SePh, Me3SiCF2P(O)OEt2 and Me3SiCF2SPh.

Au(I) complexes catalyze iso-Pictet–Spengler reactions. Ethylamine or methylamine chains were introduced at C2, C4, the nitrogen atom of indole ring, and corresponding substrates reacted in presence aldehydes catalytic amounts complexes, leading to a variety polycyclic scaffolds. Selectivity could be achieved course double reaction involving two successive aldehydes, highly complex molecules.

A copper-catalysed oxidative amidation of aldehydes via N-hydroxysuccinimide ester formation is reported. The methodology employed to prepare amides directly from aldehydes has a very wide scope, is high yielding, and does not need dry conditions. This cross-coupling reaction appears to be simple and makes use of cheap, abundant and easily available reagents.

Heterogeneous silica supported rhodium-phosphine complex catalysts are employed for the first time in the catalytic decarbonylation of aldehydes in continuous gas-phase. The reaction protocol is exemplified for the decarbonylation of p-tolualdehyde to toluene and further extended to other aromatic and aliphatic aldehydes achieving excellent results in terms of both conversion and selectivity.

[reaction: see text] A highly efficient, mild, and simple protocol is presented for the oxidation of aldehydes to carboxylic acids utilizing Oxone as the sole oxidant. Direct conversion of aldehydes in alcoholic solvents to their corresponding ester products is also reported. These reactions may prove to be valuable alternatives to traditional metal-mediated oxidations.

A versatile and highly enantioselective chiral Brønsted acid-catalyzed allenylation of aldehydes with propargyl borolane is reported. The reaction is shown to be practical and quite general with a broad substrate scope covering aryl, heteroaryl, α,β-unsaturated, and aliphatic aldehydes.