Meisenheimer-Wheland Complexes between 1,3,5-Tris(N,Ndialkylamino) benzenes and 4,6-Dinitrotetrazolo[1,5-a]pyridine. Evidence of Reversible C-C Coupling in the SEAr/SNAr Reaction

Reactions between a superelectrophilic carbon reagent, 4,6-dinitrotetrazolopyridine, and 1,3,5-tris (N,N-dialkylamino)benzenes, a supernucleophilic carbon reagent series, afford C-C coupling products which are “double σ-complexes” (W-M), Wheland-like on the 1,3,5-tris(N,N-dialkylamino) benzene moiety and Meisenheimer-like on the 4,6-dinitrotetrazolopyridine moiety. These complexes were moderately stable at low temperature, and they were characterized by NMR spectroscopy methods. 1H NMR experiments at variable temperature strongly indicate that the formation of these complexes by a nucleophile/electrophile attack is a reversible process.