Research On Base Promoted Anion-Radical Redox Relay For Cyclization

For most organic chemical reactions,a certain amount of alkali is usually added as deacid reagent.To date,there is little research on alkali as the free radicals initiators.In our previous studies of direct functional group reaction of alcohol,we found that alkali can effectively promote the amination and allyl rearrangement of alcohol.Based on these works,we further explored alkali promoted anion radical relay reactions and achieved the following research results in the synthesis methodology and reaction mechanism:1)The intramolecular C-H arylation of indole and aryl halides was promoted by o-phenanthroline-tert-butoxide potassium under metal free catalysis condition.Utilizing the intramolecular C-H arylation reaction catalyzed by metals free,we have developed a controllable method to synthesis optoelectronic materials and drug molecules that contain indole skeletons.In this process,we avoided the use of precious metal catalysts,meanwhile reduced the side reaction of dehalogenation caused by AIBN free radicals.The controllable synthesis of 6H-isoindole[2,1-a]indole was efficiently realized.2)Copper-catalyzed synthesis of indoles was realized by a redox relay of benzyl C-H intermolecular anion radical.We synthesized N-H indole skeleton from toluene derivatives and nitrile derivatives by redox strategy.We directly prepared a 'series of electroluminescent materials with indole skeleton and bioactive drug molecules from relatively cheap and easily available chemical materials.Importantly,we prepared the electron-rich derivatives and achieved the gram-level preparation of BACE1 inhibitors using this method.3)The activation of benzyl C-H bond catalyzed by CuSO4 for generating anionic free radical redox relays to synthesize fused-ring indoles.The synthesis of fused-ring indole generally requires the construction of a ring and the coupling of another ring.We synthesized the fused-ring indole efficiently by a redox relay in one-step,and successfully realized the preparation of 20 gram-level photoelectric material.This method offers novel research guidance in developing efficient strategies for construction of fused-ring indole skeletons.