C-H Functionalization of Substituted Aromatic Compounds Using Transition-Metal Catalysts

Abstract

Development of C–C formation methods has been a key research topic in synthetic organic chemistry fields. Recently, there have been extensive reports on C–H functionalization, a methodology to generate C–C bonds by activating C–H bond, while other C–N or C–O bond formations have been allowed. Traditional metal-catalyzed cross-coupling reaction has been one of the most useful synthetic methods for the formation of C–C bonds, a theme of the 2010 Nobel prize in chemistry. Yet, there is an inconvenience requiring laborious procedures to prepare organic halides or organometallic reagents. On the other hand, C–H activation can avoid these steps and it has influenced the broad field of chemical synthesis of small molecules, pharmaceuticals, fine chemicals, biomolecules, and organic-based materials. In this thesis, we have designed and performed both homogeneous and heterogeneous C–H functionalizations. Reaction optimization and substrate scope tests have been carried out to reveal the synthetic utilities. In the first chapter, we have established the first meta-selective C–H bond arylation of anilides using copper-exchanged zeolites. The Cu-zeolites have showed high catalytic activities on the low copper concentration (0.5 mol%). And we have demonstrated that Cu-zeolites are chemically stable and robust as recyclable catalysts. In the second chapter, we demonstrated a microwave-assisted meta-selective direct (hetero)arylation of pivanilides to accelerate copper catalysis. The ligand-free CuII-β system has showed improved catalytic stability over consecutive runs. In addition, homogeneous Cu(OTf)2 and heterogeneous CuII-β zeolite catalysts have been systematically compared to reveal their catalytic characteristics. In the last chapter, the main focus of the thesis, we have designed a straightforward synthetic route to access tailored triphenylenes as graphene segments. We have achieved mono- and bis-annulation of pivanilides in a one-step. Moreover, the method has been extended to the application of field-effect transistor sensor for alcohol vapor detection.