title: Tuning the Reactivity of Radical through a Triplet Diradical Cu(II) Intermediate in Radical Oxidative Cross-Coupling.
abstract: Highly selective radical/radical cross-coupling is paid more attention in bond formations. However, due to their intrinsic active properties, radical species are apt to achieve homo-coupling instead of cross-coupling, which makes the selective cross-coupling as a great challenge and almost untouched. Herein a notable strategy to accomplish direct radical/radical oxidative cross-coupling has been demonstrated, that is metal tuning a transient radical to a persistent radical intermediate followed by coupling with another transient radical. Here, a transient nitrogen-centered radical is tuned to a persistent radical complex by copper catalyst, followed by coupling with a transient allylic carbon-centered radical. Firstly, nitrogen-centered radical generated from N-methoxybenzamide stabilized by copper catalyst was successfully observed by EPR. Then DFT calculations revealed that a triplet diradical Cu(II) complex formed from the chelation N-methoxybenzamide nitrogen-centered radical to Cu(II) is a persistent radical species. Moreover, conceivable nitrogen-centered radical Cu(II) complex was observed by high-resolution electrospray ionization mass spectrometry (ESI-MS). Ultimately, various allylic amides derivatives were obtained in good yields by adopting this strategy, which might inspire a novel and promising landscape in radical chemistry.
authors.affiliation: College of Chemistry and Molecular Sciences, the Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, P. R. China.
authors.forename: Liangliang
authors.initials: L
authors.lastname: Zhou
authors.affiliation: College of Chemistry and Molecular Sciences, the Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, P. R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Yi
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, P.R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhu
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, P.R. China.
authors.forename: Xiaotian
authors.initials: X
authors.lastname: Qi
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, P. R. China.
authors.forename: Hanpeng
authors.initials: H
authors.lastname: Jiang
authors.affiliation: College of Chemistry and Molecular Sciences, the Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, P. R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, P. R. China.
authors.forename: Yuqi
authors.initials: Y
authors.lastname: Feng
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, P.R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Lan
authors.affiliation: College of Chemistry and Molecular Sciences, the Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, P. R. China.|State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China.
authors.forename: Aiwen
authors.initials: A
authors.lastname: Lei