Ring-opening of pyridines and imidazoles with electron-deficient acetylenes: En route to metal-free organic synthesis

The article is focused on the recently developed methodology for the efficient synthesis of diverse highly unsaturated previously unknown highly functionalized enamines, which comprises the mild transition-metal free hydrative ringopening of pyridines and imidazoles proceeding via zwitterionic adducts of these heterocycles with electron-deficient acetylenes. The synthesized compounds are of high synthetic and pharmaceutical value being promising intermediates for drug design.