This dissertation describes the development of new methodologies for nucleophilic monofluoromethylation, electrophilic difluoromethylation, ipsohydorxylation, nucleophilic addition reactions and synthesis of polymeric nanospheres.
Chapter 1 summarizes a brief history of organofluorine chemistry with the emphasis on application of organofluorine compounds and novel methodologies developed for introducing fluorine in organic compounds.
Chapter 2 describes a new, efficient Mitsunobu reaction using fluorinated carbon pronucleophile for the facile synthesis of monofluoromethyl derivatives of alcohols. This reaction performed under mild conditions is found to be highly feasible for primary, secondary, allylic, benzylic and alicyclic alcohols and excellent enantioselectivity is observed for chiral alcohols.
Chapter 3 deals with the synthesis of S-(difluoromethyl)diphenylsulfonium and its use as a convenient electrophilic difluoromethylating reagent for various oxygen, nitrogen and phosphorus nucleophiles.
Chapter 4 includes the synthesis of first solid-phase bound electrophilic difluoromethylating agent has been developed by an efficient, short, two step synthetic route from commercially available reagents. It has been shown that the reagent can be used for O-difluoromethylation of sulfonic acids and N-difluoromethylation of imidazoles affording pure product without further purification. This reagent may provide a valuable collection of molecules for pharmacological and materials screening through target and/or diversity oriented manual or automated library synthesis.
Chapter 5 expounds a milder and new technique to regioselectively transform aryl boronic acids to the corresponding phenols in excellent yields and high purity, using a solid PVD-H2O2 complex, which can be reused further for several runs. High level DFT calculations were also performed on model systems to study and understand the nature of these complexes.
Chapter 6 delineates a convenient protocol for the nucleophilic addition of α-fluoro-α-phenylsulfonyl-substituted methane derivatives to a variety of Michael acceptors such as, α, β unsaturated esters, ketones, sulfone, and nitriles. This methodology has been further extended to propynoates to give the corresponding adducts in moderate yields.
Chapter 7 describes the synthesis of poly(vinylpyridine) nanospheres using an emulsifier-free emulsion polymerization technique. Poly(vinylpyridine) nanospheres were used as stable support for coating the magnetite nanoparticles by a one step adsorption from colloidal solution.