The Research Of Visible Light-Induced And Electrochemical Oxidation-Induced Oxidative Coupling Reactions

The development of novel and effective chemical reaction to improve atom-economy has become an important research field in organic chemistry along with the development of green chemistry.In order to improve atom-economy,the oxidative cross-coupling of hydrocarbons as starting materials which can avoid pre-functionalization step,is an ideal synthetic method.During the past few years,visible light photoredox catalysis and electrosynthesis have emerged as a powerful technique and have provided a new way for organic transformation.The development of visible-light induced and electrochemical induced radical oxidative cross-coupling reaction is challenging and significant.In this doctoral dissertation,oxidative cross-coupling reaction in organic synthesis is introduced.Then the development of photoredox catalyzed and electrochemical catalyzed radical oxidative cross-coupling is reviewed.With respect to the green and sustainable chemistry concept,several C-H bond activation and functionalization reactions were realized by photoredox catalyzed and electrochemical catalyzed strategy.Meanwhile,the mechanism of related reactions has been preliminary explored.The main results contain the following aspects:1.By using acridine as the photosensitizer,oxygen as a benign oxidant,a simple and green Csp³-H bond of methyl aromatics and tetrahydrofuran activation approach can be achieved.The method can efficiently convert methyl aromatics to aromatic carboxylates and achieve amination of tetrahydrofuran.2.The synergistic effect of self-assembly and visible-light induced the oxidative C–H acylation of N-heterocyclic aromatic compounds with aldehydes under catalyst-free conditions was developed.The mild method can be compatible with a series of aromatic aldehydes and aliphatic aldehyde.In addition,a mechanistic study through NMR and EPR spectroscopy has been demonstrated.The mechanism of the interaction of N-heterocycles,TFA and ^tBuOOH was described,which reveals that the effect of self-assembly plays a key role in the reaction.3.By combining electrochemical oxidation and Lewis acid catalysis,an environmentally friendly electrocatalytic protocol for alkene trifluoromethylation have been developed.By using NaSO₂CF₃ as an inexpensive and stable trifluoromethylation reagent,the reaction can be compatible with a series of alcohol and nitrogen nucleophilic reagent without external chemical oxidants needed in this transformation.The gram synthesis can also be achieved which is beneficial for practical applications.4.By combining electrochemical oxidation and Lewis acid catalysis,an environmentally friendly electrocatalytic protocol for alkyne trifluoromethylation have been developed.This method breaks through the traditional metal catalytic trifluoromethylation of alkynes,which opened a new way for the direct trifluoromethylation of terminal alkyne.Mechanism studies have shown that Lewis acid could slow the anodic oxidation of CF₃SO₂Na,which make the CF₃ radical to be generated in a lower concentration to promote this transformation.