Palladium-catalyzed C3-arylation And Acylation Of Heterocycles Via Direct CH Activation

In this thesis, the direct C-H arylation of thiophenes and other heterocyclics were studied using palladium catalysts. The main obtained results were as follows: 1. With high regioselectivity, a series of benzoheterocyclic compounds were synthesized via new style bis(alkoxo)palladium complex Cat.III catalyzed C-H arylation of benzothiophenes/benzofurans with aryl MIDA boronates at 30-50 °C in moderate to excellent yields. MIDA boronates were used in C-H arylation of heterocycles for the first time. Under the optimal conditions, the benzothiophenes could be transformed into the β-arylbenzothiophenes, and the benzofurans gave only α-aryl-substituted products.2. Using pyridyl as a directing group, a series of β-acylated five membered aromatic heterocycles were synthesized at 60 oC in moderate to excellent yields. According to the study of reaction mechanism, we deduced that the reaction could proceed via a radical pathway.