Divergent product selectivity in gold- versus silver-catalyzed reaction of 2-propynyloxy-6-fluoropyridines with arylamines.

A study of the reaction of easily accessible 2-propynyloxy-6-fluoropyridines with arylamines under gold or silver catalysis is described. It has been shown that two types of isomeric oxazolopyridine imine derivatives, which represent unusual heterocyclic motifs, can be selectively obtained in moderate to excellent yields depending on the nature of the metal employed.

Au-catalyzed formation of functionalized quinolines from 2-alkynyl arylazide derivatives.

A new method for converting 2-alkynyl arylazide derivatives into functionalized polysubstituted quinolines following a gold-catalyzed 1,3-acetoxy shift/cyclization/1,2-group shift sequence has been developed. This transformation proceeds under mild reaction conditions, is efficient, and tolerates a large variety of functional groups.

Cu(I)-catalyzed oxidative cyclization of alkynyl oxiranes and oxetanes.

In the presence of a Cu(I) catalyst and a pyridine oxide, alkynyl oxiranes and oxetanes can be converted into functionalized five- or six-membered α,β-unsaturated lactones or dihydrofuranaldehydes. This new oxidative cyclization is proposed to proceed via an unusual allenyloxypyridinium intermediate.

Gold(I)-catalyzed formation of dihydroquinolines and indoles from N-aminophenyl propargyl malonates.

The use of [XPhosAu(NCMe)]SbF(6) in nitromethane at 100 °C allows the rapid and efficient formation of variously substituted dihydroquinolines, which can be subsequently converted into indoles by a rare photochemical rearrangement.