Palladium-catalyzed carbon-hydrogen bond functionalization utilizing an exo-directing strategy
Transition metal catalyzed functionalization of carbon-hydrogen bonds (C−H bonds) has become an exponentially growing field. Particularly, Pd-catalyzed methods with various directing groups (DGs) have been developed for site selectivity. In addition, the use of an oxime as a DG proved to be an efficient and removable DG. However, alcohol-based directing strategies are still rare and underdeveloped. The research and development in this dissertation mainly focused on the utilization of masked alcohols as DGs for late stage diversification. With an exo-directing strategy, the syntheses of chemically differentiated vicinal diols and 2-hydroxyalkylphenol derivatives were achieved. Through a series of studies on cyclopalladation of methine groups, the first direct C−H activation complex was prepared and characterized. Additionally, a comprehensive introduction of TM-catalyzed alkylation of aromatic C−H bonds with simple olefins was illustrated.