The overwhelming potential of heterocyclic compounds in pharmaceutical
sector continuously demands the development of new synthetic approaches. The
beginning of 19th century witnessed an era of development of various condensation
reactions for the development of new heterocyclic scaffolds. Most of the developed
classical reactions still hold great value while the field is inundated in 21st century with
the advent of catalysis. The activation of unsaturated functionalities of acyclic
compounds to undergo intramolecular cyclization via metal catalyzed approaches or
the transformation of azetidin-2-ones to functionally enriched compounds have
occupied a prominent place in heterocyclic synthesis.
Keywords: Aza-Michael Addition, Biological Activities, β-Amino Ester, β-
Lactam-Synthon Protocol, Cross-Dehydrogenative-Coupling, Cyclo-
Isomerisation, Cycloaddition, Diastereoselective, Enatioselective, Enatiomeric
Excess, Fries Rearrangement, Heterocycles, Intramolecular Amidolysis,
Intermolecular Amidolysis, Intramolecular Cyclization, Intramolecular Ullmann,
Metal-Catalyzed Reactions, Photocatalyst.
