Studies On Copper Catalyzed C-X (X=C,O,S) Coupling Reactions And Applications To Organic Functional Molecules Synthesis

C-X ?X =C, N, O, P, and S? bonds play pivotal role in biology, medicine and materials science,thus the construction of C-X bonds under mild conditions is of both theoretic and manufacture importance. For an aromatic system, the C-X bond is mainly formed by nucleophilic aromatic substitution, whereas electron-deficient aryl halides are used or N2 is needed as leaving group. The breakthrough in this field is the transition metal catalyzed C-X coupling, and the typical catalyst is Pd?0?. However, Pd?0?-catalyzed C-X coupling suffers from the usage of expensive, toxic, and unstable reagent and ligands. On the other hand, Cu-catalyzed C-X coupling shows the advantages not only in low cost and toxicity, easily accessible ligands, but also can realize some reactions that Pd-catalyst could not. In this regard, Cu-catalyzed C-X coupling shows the bright prospect in industry, while one should consider of the shortcomings such as high reaction temperature, usage of excess Cu salts, poor substrate tolerance, and sometimes the result can't be reproduced.In this thesis, we devoted to explore new methodologies for Cu-catalyzed C-X ?X = C, O,and S? bond formation, and then led to apply these methods ?C-O/C-S coupling? on the synthesis of unprecedented organic functional molecules.In chapter 1, we made the literature survey on the Cu-catalyzed C-X coupling ?X = C, O, and S? including the followings: ?a? Cu-catalyzed C-C bond construction strategies such as the arylation of CH-acids, cross-coupling of aryl halides with terminal acetylenes and organometallics?Grignard reagents, organoboron, organosilicon, and organotin compounds?, and decarboxylative coupling of carboxylic acids with sp² C-H; ?b? Cu catalyzed C-O coupling; ?c? Cu catalyzed C-S bond construction. At last, we introduced the design rationale of this thesis.In Chapter 2, we report our achievement on the Cu-catalyzed decarboxylative coupling of cinnamic acid with saturated sp³ C-H. Although the Pd or bimetallic catalysts has been employed to catalyze decarboxylative coupling of carboxylic acids with sp or sp² carbon, the coupling with sp³ carbon remains unsolved. We found that the latter reaction could be successfully achieved in the presence of Cu?0?-catalyst without any ligand. The decarboxylative coupling of cinnamic acid derivatives with sp³ C-H reaction shows good tolerance in wide range of substrates: ?a? all kinds of cinnamic acids with isopropanol; ?b? cinnamic acids with various primary and secondary alcohols, alkanes, and ethers. Remarkably, the reaction can be performed in the gram-scale. We also proposed the reaction mechanism by the means of competition test.In Chapter 3, we report the application of Cu-catalyzed C-O coupling on the synthesis of organic functional molecules. The C-O coupling of muti-phenol with electron-rich aryl iodide is hardly to be performed. By optimization of the reaction conditions, we found that such reaction can be successfully conducted in the presence of CuI-catalyst ?20%?, co-catalyst Fe?acac?3, and base K2CO3. The C-O coupling of 4-I-THTBT with catechol, resorcinol, and phloroglucinol was thus carried out, which led to the synthesis of a flexible and electron-rich heterocycles containing sulfur and nitrogen, TSNOB. Absorption spectroscopy and electrochemical studies demonstrate that TSNOB is a moderate electron donor molecule. X-ray single crystal diffraction analysis suggests that the peripheral THTBT frameworks in TSNOB show the rotational freedom, i.e., a single molecule can form a cavity. Consequently, TSNOB was employed to encapsulate the size compensative guest molecules. The preliminary result proved that TSNOB can host fullerene molecules such as C₆₀ and C70.In Chapter 4, the application of Cu-catalyzed C-S coupling on the synthesis of organic functional molecules was reported. Aryl-fused TTN ?TTN = 1, 4, 5, 8-Tetrathianaphthalene, a isomer of tetrathiafulvalene TTF? is estimated to exhibit boat or chair conformations, thus might be employed to host sphere-shaped molecules. However, these compounds haven't been reported due to the synthetic difficulties. We envisioned that the Cu-catalyzed C-S coupling would be a practical approach toward aryl-fused TTN. Using readily available zinc-thiolate complex?TBA?2[Zn?DMIT?2] as starting material, 1,2-diiodobenzene as substrate, a two-fold CuI-catalyzed C-S coupling afforded benzene-fused TTN in good yield. This approach was then successfully employed to synthesize TTNs bearing various types of aryls, and a series of aryl-fused TTNs were created. Compared with TTF, these TTNs are weak donor molecules as proved by electrochemical investigation. Single crystal structure analysis proves that these TTNs mainly take the chair conformation. Further investigation indicates that these TTNs can host fullerene molecules. For example, 2,5-dimethylthiophene-fused TTN formed the 1 : 1 inclusion complex with C₆₀. In the crystal of this complex, there are multiple intermolecular van der Waals interaction between TTN and C₆₀, and the C₆₀ molecules form the two-dimensional sheets.