Development of C–H Oxygenation and Carbonylation Reactions of Arenes

This thesis contains two parts. In the first part, it describes the development of the Cu-catalyzed and K2S2O8-mediated remote C−H oxygenation reaction of arenes for synthesis of benzocoumarines. In the second part, it demonstrates the Pd-catalyzed ortho C−H carbonylation reactions of arenes using easily installable/modifiable silicon-tethered directing groups for synthesis of salicylic acids and active HFIP esters. Chapter 1 summarizes a general approach for synthesis of phenols via aromatic C−H bond oxygenation, as well as introduces the Pd-catalyzed C−H bond carbonylation reactions using CO as C1 source for synthesis of aryl carbonyl compounds. Chapter 2 presents the Cu-catalyzed remote C−H oxygenation reaction of 2-aryl benzoic acids for synthesis of electron-rich and -neutral benzocoumarines. Based on the mechanistic understanding of the Cu-catalyzed reaction, a more general K2S2O8-mediated C−H oxygenation reaction was developed, which features general scope and excellent functional group tolerance. Preliminary mechanistic studies suggest a key oxygen radical intermediate is likely to be involved in this transformation. Chapter 3 summaries the recent advances of employment of removable/modifiable silicon directing groups for C−H bond functionalization of arenes. It also presents the development of the Pd-catalyzed silanol ortho C−H carboxylation of phenols for synthesis of salicylic acids. The reaction scope and limitation are presented. In addition, the reaction mechanism is discussed. Last, it demonstrates an efficient Pd-catalyzed PyrDipSi directed C−H alkoxylcarbonylation reaction of arenes for synthesis of active benzoates. The reaction allows for synthesis of arenes with two independent functionalizable sites, which was further elaborated on the C-7 C−H carbonylation of biologically important tetrahydrogen quinolines and the synthesis of bioactive active benzocoumarin derivative.