Executive Summary : | Carbocycles and heterocycles constitute the fundamental building blocks of pharmaceuticals, agrochemicals, natural products, and functional materials. This has inspired the discovery and development of new reactions for its syntheses and functionalizations. In this context, the expansion of sustainable catalytic methods is a focus of contemporary interest due to the adverse effects of the manufacturing process chemicals. Towards this direction, the C–H bond activation strategy that negates the need for substrate-functionalization is highly desirable and offers step- and atom-economic routes for the construction of carbo(hetero)cycles. Although C-H bond activation strategies, particularly sp2 (arene and vinylic) CH bond activation, have enjoyed exponential growth, they are known to have limitations employing sp3 C-H bond and/or sequential sp3 – sp2 C-H bonds. Therefore, the construction of carbo/heterocycles via synchronized dual sp3/sp2 C-H bonds activation constitutes the fundamental challenge and invites a worldwide quest. Additionally, apart from identifying reaction conditions that would allow the activation of the sp3 C–H bond, these reactions also need to be selective, allowing one C–H bond to be differentially activated from the rest of the ubiquitous C–H bonds to construct the novel carbo(hetero)cyclic frameworks. Thus, we believe, the development of synchronized dual sp3/sp2 C-H bonds activation chemistry will lead to the step-economic synthesis of carbo(hetero)cycles as high-value chemicals for diverse applications. In the present work, we will explore Pd-catalysis for the selective and synchronized dual sp3/sp2 C–H bonds activation of N-heterocycle linked aryl-alkyl systems and their cyclization with alkynes, allenes, alkenes, benzynes, and diazo compounds to access novel N-HETEROCYCLES TETHERED CARBO(HETERO)CYCLES in one-step for a multitude of applications. The developed protocol will be utilized as a platform technology for the functionalization of nucleobase as a promising anti-cancer hit(s). |