Urazoles as Heterocyclic Directing Groups in Ru(II)-Catalyzed Annulation of N–H/C–H Bonds with Vinylene Carbonate

The development of novel directing groups is a valuable strategy to secure the advancement of catalytic C–H functionalization. To illustrate the feasibility of urazoles as heterocyclic directing groups, we herein present the ruthenium(II)-catalyzed annulation of N–H/C–H bonds on N-aryl urazoles with vinylene carbonate. This transformation provides the rapid construction of triazolocinnoline derivatives as hemiaminal and dehydrated forms. A series of mechanistic investigations and post-transformations highlighted the amenability of the developed method.