Executive Summary : | The van der Waals radius of fluorine is only 23% higher than that of hydrogen. The high strength of the C-F bonds combined with low polarizability makes organofluorine molecules very unique. Almost 20-25% of small-molecule pharmaceutical products and 60% agrochemicals contain at least one fluorine atom1. Particularly fluorinated aromatics and heteroaromatics have received substantial attention in this regard. The introduction of a fluorine atom into the target molecule changes the lipophilicity and solubility of the compound and considerably affects the basicity and acidity of functional groups and tendency for hydrogen bonding. This change in molecular nature improves metabolism, membrane permeability, efficiency of binding to biological targets and bioavailability. However, selective introduction of a fluorine atom or a polyfluoroalkyl substituent into the desired structure is a synthetic challenge and, in each particular case, it is performed by a dedicated method. We envision the light driven regioselective direct fluorination and fluoroalkylation i.e., trifluoromethylation of arenes and heteroarenes using an economical photocatalyst. Here, the interaction of organic molecules and photocatalysts via single electron transfer (SET) with triplet excited state of a metal or dye based photocatalyst generated through visible-light-induced metal-to-ligand charge transfer (MLCT), yields reactive intermediates from the organic molecules, which can be manipulated to produce various products under mild reaction conditions. Two distinctive cycles, oxidative quenching and reductive quenching are frequently invoked to explain the mechanism of photo redox catalysis. In this research proposal, the radical intermediate will regioselectivity add in nucleophilic fashion, which will further transform to re-aromatize product through appropriate changes. |