Synthesis Of N-Heterocycles And Diaryl Sulfides Via C-H Activation

Owing to advantages of convenience,economical efficiency,directness,high efficiency and environmental friendliness,C-H activation strategy becomes one of the hottest field in organic chemistry,and is widely applied in designed synthesis of natural products,medicines and bioactive molecules.Quinazolinone,2-quinolinone and diaryl sulfide compounds have good biological activity,medicinal activity and material characteristics,and their synthesis is widely concerned.Efficient establishment of more quinazolinones and 2-quinolinone derivatives and simpler establishment of diaryl sulfide compound by C-H activation strategy have important research significance.By understanding and application of C-H activation strategy and study on synthesis methods of quinazolinone,2-quinolinone and diaryl sulfide compounds,the paper acquires the following achievements:?1?An efficient and practical copper-catalyzed one-pot method for synthesis of tetrahydroisoquinolino[2,1-a]quinazolinone derivatives has been developed.The protocol uses inexpensive Cu I as the catalyst,economical and environment friendly oxygen as the oxidant,and the corresponding N-fused heterocycles were prepared in good yields.The one-pot approach underwent sequential copper-catalyzed N-arylation,intramolecular aerobic oxidative cyclization,and the newly synthesized products provided diverse structures for screening of biological molecules.?2?We have developed simple,efficient and general transition metal-free intramolecular regioselective couplings of alphatic and aromatic C-H bonds.The protocol uses readily available aryl triazene as the radical initiator,cheap K₂S₂O₈ as the oxidant,and the couplings were performed well with excellent tolerance of functional groups.Interestingly,?-carbon configuration of some amino acid residues in the substrates was kept after the reactions.Therefore,the present study should provide a novel strategy for regioselective cross-dehydrogenative couplings of two different C-H bonds.?3?We have developed a highly efficient iron or boron-catalyzed C-H arylthiation of substituted phenols at room temperature.The protocol uses readily available 1-?substituted phenylthio?pyrrolidine-2,5-diones as the arylthiation reagents,inexpensive and environmentally friendly FeCl₃ or BF₃·OEt₂ as the catalyst,no ligand,additive and extrusion of air were required,and the corresponding diaryl sulfides were prepared in good to excellent yields.Further,a simple and efficient transition metal-free method for arylthiolation of arylamines has been developed,in which avoided contamination of transition metal-catalysts to the target products.