Development of Novel Catalytic Transformations Towards Valuable Organic Intermediates

The main scientific objective of this doctoral research was to develop powerful metal-free organic (photo)catalytic systems to efficiently realize new carbon-carbon and carbon-heteroatom bond forming transformations of practical importance. These approaches had to meet the sustainability requirements for green chemical productions by using effective, non-toxic, safe, readily available from economic precursors and potentially recyclable catalysts. In doing so, the preparation of synthetically relevant organic intermediates could be promptly achieved in mild conditions, thus envisaging the potential application of the studied methodologies at preparative scale. Chapter I introduces the general concepts of organic catalysis, including both polar and radical chemistry. Moreover, it aims to illustrate the physicochemical principles underlying the operative mechanisms of the abovementioned catalytic systems. Chapter II focuses on the development of a photochemical strategy for the iodoperfluoroalkylation of alkenes triggered by a simple perylene diimide photocatalyst. Successively, this Chapter describes the translation of the established procedure into continuous flow with the aim of up-scaling the preparation of the relevant perfluorinated compounds. Chapter III discusses the use of photoactive nitrogen-doped carbon dots as catalysts for the light-driven perfluoroalkylation of electron-rich organic substrates. This approach allows the extension of the reactivity to more inert arenes and heteroarenes. Chapter IV describes the development of green polar organocatalytic methodologies in aqueous media by exploiting the surface amino functionalities of the very same nitrogen-doped carbon nanoparticles. Remarkably, this original approach has been made possible by a fine characterization of the nanomaterial at unprecedent level of detail. Chapter V shows how another carbon-based nanomaterial, namely carbon nitride, can trigger photochemical aryl amination reactions of high synthetic importance. Interestingly, this transformation is carried out under flow conditions by means of an innovative oscillatory microstructured reactor to overcome the challenges associated with handling solids in flow.