1,2,3-Triazolium-1-unsubstituted methanides, carbon analogues of triazole-N-oxides: A 1,3-dipole cascade from 1,2,3-triazolium-1-methanide to 1,2,4-triazinium-4-methanide: New routes to pyrrolo[1,2-c] [1,2,3]triazoles, pyrrolo[1,2-d] [1,2,4]triazines and substituted 1-aminopyrroles. Azolium 1,3-dipoles