An Organocatalytic Regiospecific Synthesis of 1,5-Disubstituted 4-Thio-1,2,3-triazoles and 1,5-Disubstituted 1,2,3-Triazoles.

Organocatalytic azide-ketone [3+2] cycloaddition (OrgAKC) of a variety of 1-aryl-2-(arylthio)ethanones and 1-alkyl-2-(alkylthio)ethanones with different aryl or alkyl azides is reported in dimethyl sulfoxide or solvent-free under ambient conditions to furnish 1,5-disubstituted 4-thio-1,2,3-triazoles in a regiospecific manner, which are further converted into useful 1,5-disubstituted 1,2,3-triazoles by treatment with Raney Ni at 25 °C for 1-3 h. Notable features of the OrgAKC reaction include high rate and selectivity, solvent-free conditions, easily available substrates and catalysts, a wide range of synthetic and medicinal applications, and excellent yields generating a vast library of triazoles.