Rhodium(II)-Catalyzed Denitrogenative Transformations of N-Sulfonyl-1,2,3-triazoles

N-Sulfonyl-1,2,3-triazoles are valuable precursors for the generation of α-imino carbene intermediates in the presence of the metal catalysts, especially rhodium(II) complexes. Due to the presence of electrophilic carbene and nucleophilic nitrogen, these reactive intermediates can easily be incorporated into many annulations, cycloadditions, C-H or O/N/S-H bond insertions and functionalization reactions. A large number of pharmaceutically important nitrogen-based building blocks can be constructed via this direct and atom-economical carbene strategy. In this review, we have described the transformations of N-sulfonyl-1,2,3-triazoles based on α-imino rhodium(II) carbene intermediates.