NOVEL C-X/C-X BOND FORMATIONS USING 1,3-DICARBONYLS AND THEIR DERIVATIVES IN THE SYNTHESIS OF POLYSUBSTITUTED HETEROCYCLES

Abstract

Due to their ambiphilic nature, 1,3-dicarbonyls and their derivatives, phenylacetones and phenylacetophenones, are versatile synthons for the construction of polysubstituted heterocycles via multiple C-X/C-X (X = C, N) bond formations. A wide variety of 1,3-dicarbonyls, including substituted ones, are commercially available and inexpensive. The aim of this thesis is to develop novel simple one-pot protocols for synthesizing polysubstituted heterocycles using reagents and catalysts of low toxicity under mild reaction conditions, having an expansive scope and also readily scalable. These protocols could potentially allow a large library of target molecules to be efficiently synthesized with minimal effort, cost, time and energy. The syntheses of polysubstituted pyridopyrimidinones, imidazopyridines pyrroles and furans will be discussed with an emphasis on providing a minimalistic approach of employing simple and green alternatives whenever possible, without compromising yield. Highlights of this thesis include newly conceived 2-aminopyridine a-bromination shuttle system and a Lewis base enhanced Bi(III)-catalyzed reaction.