Molecular iodine mediated novel organic transformation leading towards the synthesis of important heteroaromatics and synthetically useful substances

Abstract

The content of the present thesis entitled Molecular iodine mediated novel organic transformation leading towards the synthesis of important heteroaromatics and synthetically useful substances is divided into five chapters based on the results of experimental work performed during the entire Ph.D.course. newlineChapter 1: An overview of molecular iodine-mediated organic reactions newlineReactions employing iodine provide mild operating conditions usually allowing large substrate scope, high yields, regio/stereoselectivities, short reaction time and a simple workup procedure. In the first chapter we have describes an overview ofmolecular iodine-mediated types of organic reactions toward synthesis of valuable heterocycles and synthetically useful starting materials. Special emphasis is given toiodocyclization, multicomponent reaction, C-H bond functionalization, and dehydrogenative aromatization reaction. newlineChapter 2: Iodine-mediated oxidative cross-coupling of 2-aminopyridine and aromatic terminal alkyne: A practical route to imidazo[1,2-a]pyridine derivatives newlineImidazo[1,2-a]pyridine scaffolds are valuable biologically active heterocycles which exhibit a wide range of biological activities like antifungal, antiulcer, antitumor, analgesic, antiviral, antiprotozoal, antipyretic, anti-inflammatory and anxioselective activities.Several drugs contain imidazo[1,2-a]pyridine moieties such as alpidemand zolpidem, necopidem,saripidem, miroprofen and zolimidineare available on the market. In this chapter, we have demonstrated A novel, transition-metal free route leading to imidazo[1,2-a]pyridine derivatives via iodine-mediated oxidative coupling between 2-aminopyridine and aromatic terminal alkyne (Scheme 1). newline newline newline newline newline newline newline newlineScheme 1 Synthesis of imidazo[1,2-a]pyridine derivatives from 2-amino pyridines and alkynes. newline newlineA library of imidazo[1,2-a]pyridine derivatives was prepared with varying both aromatic terminal acetylenes and 2-aminopyridines using our optimized reaction condition. Again, the method for imidazopyridine formation with concomitant