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

The development of novel directing\ngroups is a valuable strategy\nto secure the advancement of catalytic C–H functionalization.\nTo illustrate the feasibility of urazoles as heterocyclic directing\ngroups, we herein present the ruthenium(II)-catalyzed annulation of\nN–H/C–H bonds on <i>N</i>-aryl urazoles with\nvinylene carbonate. This transformation provides the rapid construction\nof triazolocinnoline derivatives as hemiaminal and dehydrated forms.\nA series of mechanistic investigations and post-transformations highlighted\nthe amenability of the developed method.