Studies on site-selective C–H functionalization of pyridines through electron donor-acceptor complex

Abstract

Pyridine is a valuable functional group that is frequently found in various bio-active molecules, natural products, and drugs, thus the development of site-selective functionalization of pyridines has been considered important. Especially, activated pyridines such as pyridinium salts have high regioselectivity and photochemical properties, therefore, using these properties, various methodologies have been developed. In this thesis, I will introduce the functionalization of pyridines using N-amidopyridinium salt through single-electron transfer (SET) from electron donor-acceptor (EDA) complexes under the visible-light irradiated condition. Chapter 1 presents the enantioselective functionalization of pyridines using chiral N-heterocyclic carbene catalysis and cinnamaldehyde derivatives. Chapter 2 introduces the reaction of C–N bond cleavage of cyclic amine using a difluorocarbene reagent, then an in-situ-generated intermediate reacts with pyridinium salt through a halogen-atom transfer strategy.