Supported Au Nanoparticles-Catalyzed Regioselective Dehydrogenative Disilylation of Allenes by Dihydrosilane.

Supported Au nanoparticles on TiO catalyze the unprecedented dehydrogenative disilylation of monosubstituted and 1,1-disubstituted allenes by Et SiH exclusively on the terminal double bond in a stereoselective manner. Treatment of the disilylation products with H O, in a one-pot operation also catalyzed by Au/TiO , leads to 3-alkylidene-1,2,5-oxadisilolanes, an unknown class of heterocyclic compounds, which are excellent scaffolds for the stereoselective synthesis of alkenes under Hiyama-type cross-coupling conditions.

Synthesis of Formate Esters and Formamides Using an Au/TiO₂-Catalyzed Aerobic Oxidative Coupling of Paraformaldehyde.

A simple method for the synthesis of formate esters and formamides is presented based on the Au/TiO₂-catalyzed aerobic oxidative coupling between alcohols or amines and formaldehyde. The suitable form of formaldehyde is paraformaldehyde, as cyclic trimeric 1,3,5-trioxane is inactive. The reaction proceeds via the formation of an intermediate hemiacetal or hemiaminal, respectively, followed by the Au nanoparticle-catalyzed aerobic oxidation of the intermediate.

cis-Semihydrogenation of alkynes with amine borane complexes catalyzed by gold nanoparticles under mild conditions.

Supported gold nanoparticles catalyze the semihydrogenation of alkynes to alkenes with ammonia borane or amine borane complexes in excellent yields and under mild conditions. Internal alkynes provide cis-alkenes, making this protocol an attractive alternative of the classical Lindlar's hydrogenation.