Research team of Professor Lei Aiwen of Wuhan University: visible light promotes the oxidative phosphorylation of C (SP3) - h to α - aminophosphate without additional oxidant

The research team of Professor Lei Aiwen of Wuhan University was invited to be our first reporting object in early January (click to view) Recently, Professor Lei's research team has made some new progress in the catalytic synthesis of phosphorus compounds In this regard, CBG information first paid attention to and reported the latest research results of "old friends" Brief introduction of Lei Aiwen research group the research group was founded in March 2005 The aim is to develop: 1 Highly selective and efficient transition metal catalyzed construction of carbon carbon bond and carbon heterobond, such as oxidative coupling reaction, C-H bond functionalization; 2 Activation of small molecules (such as CO, O2, N2O, H2O2, NH3, ClO2 -) and effective use of these small molecules for organic synthesis; 3 Study on the mechanism of metalloenzyme, including kinetic research and active intermediates So far, more than 260 papers have been published in international core journals such as J am Chem SOC., angelw Chem Int ed., chem Rev., chem Commun., and more than 10000 citations have been made Prof Lei Aiwen's profile source: Lei Aiwen of Wuhan University, vice president of higher Research Institute of Wuhan University, Professor of School of chemistry and molecular science, has worked in Wuhan University since 2005 In 2010, he won the national fund for Distinguished Young Scholars; in 2013, he served as the vice president of higher Research Institute of Wuhan University; in 2014, he was elected as the distinguished professor of Changjiang Scholars of the Ministry of education; in 2015, he became a member of the Royal Society of chemistry Cutting edge scientific research achievements: under the condition of no additional oxidant, visible light promotes the oxidative phosphorylation of C (SP 3) - h to synthesize α - aminophosphate It has been an important scientific problem to develop a mild and sustainable catalytic synthesis strategy of phosphorus compounds α - aminophosphate and α - aminophosphate have important biological and agricultural activities, and the strategy of oxidative C (SP 3) - H phosphorylation is undoubtedly the most direct and economic way to synthesize these compounds Recently, Professor Lei Aiwen's research team of Wuhan University has made some important research progress in this field At present, the research on the phosphorylation of n-o-ortho-c (SP 3) - H promoted by oxidants mainly focuses on the use of n-phenyltetrahydroisoquinoline skeleton as the central substrate to provide the corresponding α - aminophosphate (Fig 1) Fig 1 phosphorylation of C (SP 3) - H oxidation promoted by oxidant (source: chem Commun.) in recent years, with the development of photocatalysis, phosphorylation of n-phenyltetrahydroisoquinoline developed under the catalysis system of light and oxidant has been quite mature However, in the catalytic system of light and oxidant, the C (SP 3) - H oxidation of N, N-dialkylamine substrate, C-N bond breaking and the oxidation of triethyl phosphite used lead to the phosphorylation of N, N-dialkylamine skeleton N-atom ortho-c (SP 3) - H, which is still challenging (Fig 2) Fig 2 C (SP 3) - H oxidative phosphorylation of light and oxidant catalysis system (source: chem Commin.) based on the study of oxidative cross coupling reaction between two nucleophiles realized without additional oxidant, Professor Lei Aiwen's team of Wuhan University, combined with the synergistic effect of photocatalysis and proton reduction catalysis, realized the nitrogen oxide atom neighborhood C (SP 3) promoted by visible light ）-H phosphorylation The method avoids the use of equivalent oxidant, effectively inhibits the oxidation side reaction, and efficiently realizes the synthesis of α - aminophosphate (Fig 3) Fig 3 phosphorylation of C (SP 3) - h by CO catalysis of photocatalysis and cobalt Catalysis (source: chem Commun.) the reaction system has a good substrate application range (Fig 2) Different n-alkylaniline derivatives can be well compatible with this reaction system F The halogen substituted substrates such as Cl, Br can also obtain the target products with good yield, which provides the possibility for further chemical conversion I n addition, besides P (OET) 3, P (OME) 3, P (OiPr) 3 and P (onbu) 3 can also be used as phosphorylation reagents, and the target products can be successfully obtained in high yield It shows the universality of the reaction and its potential application value (Figure 4) Figure 4 Substrate range of α - aminophosphate synthesis (source: chem Commun.) in order to deepen the understanding of the reaction, the team has done a series of mechanism studies, including free radical inhibition experiment and kinetic experiment Based on these experimental results, the following possible mechanisms are proposed: at first, under the irradiation of blue LED, the ground state photocatalyst is excited to the excited state, and then through the single electron transfer (set) process with N, N-dimethylaniline, the free radical cation 8 and the reduced state photocatalyst are obtained Free radical cation 8 is deprotonated to produce carbon free radical intermediate 9, which, after a single electron transfer (set) process with CO (III) complex, produces imine intermediate 10 and CO (II) CO (II) further oxidizes the reduced photocatalyst back to the ground state, realizes the photocatalyst's catalytic circulation, and produces CO (I) P (OET) 3 was used as a nucleophilic reagent to capture n, n-dimethylcations and produce P cation adduct 11 Under the promotion of PhCOONa, the target product was obtained after nucleophilic rearrangement The protonation of CO (I) results in CO (III) - H after capturing a proton, H2 is generated and CO (III) is regenerated (Fig 5) Fig 5 the possible mechanism of oxidative C (SP 3) - H phosphorylation realized by photocatalysis and cobalt Catalysis (source: chem Commun) This work developed an efficient method of nitrous oxide ortho-c (SP 3) - H phosphorylation to synthesize α - aminophosphate through the synergistic action of photocatalysis and cobalt catalysis, successfully avoiding the use of equivalent additional oxidant The mechanism study shows that the imine cation is the key intermediate of the phosphorylation method The job has been received by chem Commin Paper link: http://pubs.rsc.org/en/content/articlelanding/2018/cc/c7cc09624k Professor Lei Aiwen's research group homepage: http://aiwenlei.who.edu.cn/ about the increasing importance of CBG figures in scientific and technological elements in economic life today, China ushered in the "node of scientific and technological explosion" Behind the progress of science and technology is the work of countless scientists In the field of chemistry, in the context of the pursuit of innovation driven, international cooperation has been strengthened, the influence of Returned Scholars in the field of R & D has become increasingly prominent, and many excellent research groups have emerged in China For this reason, CBG information adopts the 1 + X reporting mechanism CBG information, chembeango app, chembeango official microblog, CBG wechat subscription number and other platforms jointly launch the "CBG characters" column, approach the domestic representative research group, pay attention to their research, listen to their stories, record their demeanor, and explore their research spirit.