Selective C-H and C-C Bond Functionalization of Benzo-Fused N-Heteroaromatic Compounds

Abstract

The present thesis, entitled “Selective C-H and C-C Bond Functionalization of Benzo-Fused N-Heteroaromatic Compounds” is divided into five chapters based on the results obtained from the experimental works during the course of PhD research period. Chapter-1 includes a brief introduction about the importance of C-H activation process for Nheterocyclic compounds, the problems associated with the classical processes and a short account of the literature reports for C-H activation involving N-oxide chemistry to solve the above shortcomings by both conventional and green chemistry protocols. Each of the following chapters contains an introduction, previous literature reports, present results and discussion, experimental section and references. The spectral data for the newly synthesized molecules are provided in the Annexure I-IV. Chapter 2 reports the regioselective deoxygenative C2-cyanation of quinoline N-oxides with trimethylsilyl cyanide (TMSCN) under a completely metal-, activator-, catalyst- and solventfree condition using both conventional heating and microwave irradiation methods. The reaction is both regio- and chemoselective and the mechanistic investigations revealed the dual role of TMSCN as the cyanation agent as well as an activator. Late-stage cyanation of bioactive molecules quinine and (±)-α-tocopherol modified quinoline derivative is also demonstrated. Notably, the product gets sublimated during the reaction and thus, can be easily isolated, avoiding any aqueous work-up.