Transition-Metal Catalyzed Carbon–Carbon Couplings

The transition-metal catalyzed carbon-carbon bond formation is a fundamental reaction in organic synthesis, which became one of the most popular topics. This protocol has been substantially modified and expanded over the past 30 years, providing an indispensable and simple methodology for preparative organic chemists. Based on the pioneering works on various cross-coupling reactions, herein, the formation of C-C bonds and its applications in organic synthesis has been studied.There are three chapters in this dissertation:The first chapter is about ligand-free Fe/Cu co-catalyzed alkynylation coupling reactions. The study mainly focuses on the coupling reaction of aryl halides including aryl iodides and bromides with various alkynes without using ligand in the presence of the low-cost, benign and easily available Fe-Cu catalyst. It is noteworthy that no homocoupling product of alkyne was obtained.The second chapter is about Mizoroki-Heck reactions catalyzed by tridentate thiosemicarbazones Pd(II) complexes, which are known to exhibit a wide range of biological activities. However, their application as catalyst precursors is still a relatively new area of study and our work in this area has firmly established that these stable complexes are good catalyst precursors for the Mizoroki-Heck coupling reactions.The third chapter is about nickel-catalyzed direct C-H arylation of unactivated arenes with aryl halides. Palladium catalysts are known to catalyze the C-H bond arylation of arenes. However, nickel complexes were rarely reported to be used in the formation of this type of reaction. We found that nickel could catalyze the direct arylation of unfunctionalized simple aromatic arenes using aryl halides without using any additives. The catalyst system is low cost and readily available and therefore provides a valuable addition to the nickel-catalyzed direct C-H arylation of arenes.