Research On The Copper-Catalyzed C-N And C-Cl Bond Formation Reactions

The C-N and C-Cl bonds, which are widely present in various compounds, and play a key role in numerous chemical reactions. Enaminone compounds are utilized as important starting materials to synthesize drugs like anticonvulsants, as well as useful intermediates to produce various heterocyclic compounds. Various chemicals containing C-C and C-N bond can be synthesized with aryl and heteroaryl chlorides through the coupling reactions, such as, Still/Suzuki, Heck, Sonogashira, etc.. Additionally, chlorination reaction is adopted as quite an important route to introduce halogen functional group into organic molecules.In this paper, an exploration and research is conducted to synthesize enaminone compounds as well as aromatic and heteroaromatic chlorides via building C-N and C-Cl bond, under the presence of Copper catalyst which is cheap, easily available and environment-friendly, and the target products have been successfully obtained in an efficient manner.1. The condensation reaction between4-methoxyaniline and acetyl acetone was selected as a model reaction, and the enaminone compound was obtained in a yield98%based on the optimized reaction conditions:CuCl as a catalyst, THF as solvent, and the reaction maintained under room temperature. The condensation reactions between different aromatic/aliphatic amines and1,3-dicarbonyl compounds have also been performed effectively and smoothly, and the yields of target products are within75-98%.2. The chlorination of1-bromo-4-methylbenzene was selected as a model reaction, and1-chloro-4-methylbenzene can be obtained in98%GC yield. The optimal reaction conditions were found out as:Cu2O/L-proline as a catalyst, TMAC as a chlorine source, EtOH as solvent, and react at110℃. The research results indicate that various aryl and heteroaryl bromides could be effectively converted into corresponding chlorides in65-98%yield through halogen exchange reactions. To the best of our knowledge, this catalytic bromide-chloride exchange on heteroaromatic bromides is the first example reported on such reactions.