Esters, sulfones, and ketones were C-aminoimidoylated and C-thiocarbamoylated by benzotriazole-1-carboxamidines 8a-g and 1-(alkyl-or-arylthiocarbamoyl) benzotriazoles 9a- i, respectively. The present work represents the first systematic approach to these compound classes, the few previously known examples of which were obtained by diverse approaches.