Search

An efficient process based on the gold-catalyzed redox reaction has been developed to oxidize 1,2-diarylacetylene or ynamide to 1,2-diaryldiketone or α-keto imide respectively. This process can tolerate a variety of functional groups and affords 1,2-dicarbonyl compounds in excellent yields under mild reaction conditions.

Furans, pyrroles, and thiophenes are efficiently prepared by gold-catalyzed dehydrative cyclizations of readily available, heteroatom-substituted propargylic alcohols. The reactions are rapid, high-yielding, and procedurally simple, giving essentially pure aromatic heterocycles in minutes under open-flask conditions with catalyst loadings as low as 0.05 mol %.

The gold-catalyzed cyclization of monopropargylic triols to form olefin-containing spiroketals is reported. The reactions are rapid and high yielding when 2 mol % of the catalyst generated in situ from Au[P(t-Bu)(2)(o-biphenyl)]Cl and AgOTf is employed in THF at 0 degrees C. A range of differentially substituted triols leading to substituted 5- and 6-membered ring spiroketals were prepared and function well in the reaction.

In the presence of a gold catalyst and 8-ethylquinoline N-oxide, a homopropargylic ether bearing an electron-rich aromatic ring or an alkenyl group can be converted into a cis-cyclobutanone smoothly. An α-oxo gold carbenoid is proved to be the key intermediate, and it can evolve into an oxonium ylide. [ABSTRACT FROM AUTHOR]

α-Oxo gold carbenoids generated by the oxidation of N-arylynamides can be trapped intramolecularly at the ortho position of the aryl ring to give functionalized oxindoles under mild reaction conditions. Pyridine N-oxide works as the oxidant, ligand, and base in this transformation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A general Pd/g-C3N4 catalyzed carbonylative cyclization of 2-bromonitrobenzenes and alkynes. • Mo(CO) 6 as both the CO surrogate and the reductant. • Nitroarenes as the nitrogen source. • Good yields of quinolin-4(1 H)-ones products. • Catalyst is recyclable. A palladium supported on graphitic carbon nitride (Pd/g-C 3 N 4) catalyzed carbonylative cyclization of 2-bromonitrobenzenes and alkynes has been developed for the expedite construction of quinolin-4(1 H)-one scaffolds. By using a low loading heterogeneous palladium catalyst, Mo(CO) 6 as both the CO surrogate and the reductant, and nitroarenes as the nitrogen source, the reaction proceeded well to give a variety of quinolin-4(1 H)-ones in good to excellent yields. [ABSTRACT FROM AUTHOR]