Transition-metals-catalyzed Directing Groups Mediated C-C Bonds Formation Reactions

C-H bond is the most basic structure of organic compounds, and C-C bond is the core of the organism, then construction of C-C bonds become an important content of organic synthesis, however, C-H bond activation is a particularly important way. And the target molecule can be synthesized by the strategy, which shows high atom economy and high selectivity. In the C-H bond activation reactions, it can improve the efficiency of the reactions by using suitable directing groups and transition metals catalyst, and the constuctiong of C-C bond can be completed efficiently.In this thesis, we focus on the transition-metals-catalyzed C-C bonds formation reactions, in which different directing groups were employed. The whole work is mainly composed of following five parts:In part one, we investigated and summarized the methods to build C-C bonds by different directing groups at home and abroad. Besides, we also analyzed the basics and significance of the selection of the subject.In part two, we studied palladium-catalyzed ortho-olefination of phenyl acetic and phenyl propylacetic esters via C–H bond activation. This work started from cheap and readily available phenylacetate and benzenepropanoic acid, and employed the generated esters as the directing group. In the transformation, the oxygen atom from carbonyl group together with the palladium atom form a six or seven-membered ring transition state with the aid of 1,10-phenanthroline. Subsequently, the ortho-alkenyl product was obtained in high regioselectivity.In part three, we studied palladium-catalyzed phenethylamine protected by oaxlyl amide and heterocyclic aromatic double C-H bond activation reaction. Aromatic amine is a very important nitrogen-containing compound. And the formation of a biologically active molecular skeleton can be achieved when it reacted with thiophene or furan. These molecules were widely existed in natural products and pharmaceutical molecules. So the research on this part is particularly important.In part four, we studied rhodium(III)-catalyzed oaxlyl amide protected benzylamineand heterocyclic aromatic double C-H bond activation reaction, then extened experiments were conducted with this product, cyclization of the generated products was also occurred in the presence of iodobenzene diacetate.In part five, we did a new study on the basis of the part four. We use the product benzylamine reacted with heterocyclic aromatic as the substrate, conducted a series of studies. The sulfur atom was used as the directing group, and it could realize the transformation of alkenylation and alkynylation under the palladium-catalysed conditions.The structures of the products were identified by 1H NMR、13C NMR and HRMS. And a possible reaction mechanism of the reaction has also been was aslo proposed.