Hydrogen atom transfer(HAT)is an elementary mechanistic step in organic synthesis.The photoredox-catalyzed HAT has transformed organic synthesis by enabling the activation and subsequent cross-coupling of traditionall...Hydrogen atom transfer(HAT)is an elementary mechanistic step in organic synthesis.The photoredox-catalyzed HAT has transformed organic synthesis by enabling the activation and subsequent cross-coupling of traditionally inert yet ubiquitous C(sp^(3))-H bonds.展开更多
A conceptually novel,trifunctional sulfoximine-mediatedγ-functionalization of unactivated C(sp^(3))–H bonds has been achieved.The reaction is initiated by the photo-induced homolytic cleavage of an N–S bond in the ...A conceptually novel,trifunctional sulfoximine-mediatedγ-functionalization of unactivated C(sp^(3))–H bonds has been achieved.The reaction is initiated by the photo-induced homolytic cleavage of an N–S bond in the absence of photosensitizer,and proceeds sequentially through a cascade of 1,5-hydrogen atom transfer,1,4-functional group migration,desulfoximination and a Minisci reaction.A major feature of this approach is the use of sulfoximine as a traceless directing group.Other positive properties include mild conditions,simple operation,exclusive site-selectivity,high product diversity and the avoidance of additional photosensitizers.The protocol provides a new reaction mode for HAT-induced C(sp^(3))–H functionalization,and allows a much broader chemical space for sulfoximine studies.展开更多
MXene has shown distinctive advantages as anode materials of lithium-ion batteries. However, local surface chemistry, which was confirmed that can block ion transfer and limit redox reaction, has a significant effect ...MXene has shown distinctive advantages as anode materials of lithium-ion batteries. However, local surface chemistry, which was confirmed that can block ion transfer and limit redox reaction, has a significant effect on electrochemical performance. Herein, annealing MXene under hydrogen was employed for removing-F and turning-OH to-O terminations. We demonstrate that it improves the kinetics of Li-ion transport between the electrolyte and electrode. As a result, a lower interfacial charge transfer impedance was obtained. The electrochemical measurement exhibited that a nearly 2-fold increase of specific capacity was achieved for the annealed MXene.展开更多
Aliphatic alcohols and amides are highly valued,ubiquitous chemicals in synthetic chemistry.Radical-promoted regioselective functionalization of unactivated C(sp^(3))–H bonds offers an atom and step economic manner f...Aliphatic alcohols and amides are highly valued,ubiquitous chemicals in synthetic chemistry.Radical-promoted regioselective functionalization of unactivated C(sp^(3))–H bonds offers an atom and step economic manner for direct transformation of aliphatic alcohols and amides,especially structural elaboration of complex natural products and bioactive molecules without de novo synthesis.Despite the rapid growth of hydrogen atom transfer(HAT)processes mediated by O-or N-centered radicals generated from prefunctionalized precursors of alcohols and amides in the past few years,exploration of remote C(sp^(3))–H functionalization via HAT mediated by unprotected alcohols or amides lags behind,due to the difficult homolysis of O–H and N–H bonds with high bond-dissociation energies(BDEs).In this minireview,the recent advances in regioselective C(sp^(3))–H functionalization mediated by unprotected alcohols and amides are summarized.展开更多
A high growth rate fabrication of diamond-like carbon（DLC）films at room temperature was achieved by helicon wave plasma chemical vapor deposition（HWP-CVD）using Ar/CH4gas mixtures.The microstructure and morphology ...A high growth rate fabrication of diamond-like carbon（DLC）films at room temperature was achieved by helicon wave plasma chemical vapor deposition（HWP-CVD）using Ar/CH4gas mixtures.The microstructure and morphology of the films were characterized by Raman spectroscopy and scanning electron microscopy.The diagnosis of plasma excited by a helicon wave was measured by optical emission spectroscopy and a Langmuir probe.The mechanism of high growth rate fabrication for DLC films by HWP-CVD has been discussed.The growth rate of the DLC films reaches a maximum value of 54μm h^-1at the CH4flow rate of 85 sccm,which is attributed to the higher plasma density during the helicon wave plasma discharge.The CH and Hαradicals play an important role in the growth of DLC films.The results show that the Hαradicals are beneficial to the formation and stabilization of C=C bond from sp^2to sp^3.展开更多
基金We are grateful for financial support from the National Key R&D Program of China(2021YFA1502500)National Natural Science Foundation of China(22071203)Fundamental Research Funds for the Central Universities(20720210014).
文摘Hydrogen atom transfer(HAT)is an elementary mechanistic step in organic synthesis.The photoredox-catalyzed HAT has transformed organic synthesis by enabling the activation and subsequent cross-coupling of traditionally inert yet ubiquitous C(sp^(3))-H bonds.
基金supported by the National Natural Science Foundation of China(21971173,22001185,22171201)the Natural Science Foundation of Jiangsu Province(BK20200852)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘A conceptually novel,trifunctional sulfoximine-mediatedγ-functionalization of unactivated C(sp^(3))–H bonds has been achieved.The reaction is initiated by the photo-induced homolytic cleavage of an N–S bond in the absence of photosensitizer,and proceeds sequentially through a cascade of 1,5-hydrogen atom transfer,1,4-functional group migration,desulfoximination and a Minisci reaction.A major feature of this approach is the use of sulfoximine as a traceless directing group.Other positive properties include mild conditions,simple operation,exclusive site-selectivity,high product diversity and the avoidance of additional photosensitizers.The protocol provides a new reaction mode for HAT-induced C(sp^(3))–H functionalization,and allows a much broader chemical space for sulfoximine studies.
基金financial support provided by the National Key R&D Program of China (2016YFA0200400)the Jilin Province/Jilin University co-Construction Project-Funds for New Materials (SXGJSF2017-3, Branch-2/440050316A36)+4 种基金the National Natural Science Foundation of China (Grant nos. 91545119, 21761132025, 21773269 and 51372095)the Youth Innovation Promotion Association CAS (Grant no. 2015152)Strategic Priority Research Program of the Chinese Academy of Sciences Chinese Academy of Sciences (Grant nos. XDA09030103 and XDA09040203)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT)"Double-First Class" Discipline for Materials Science & Engineering
文摘MXene has shown distinctive advantages as anode materials of lithium-ion batteries. However, local surface chemistry, which was confirmed that can block ion transfer and limit redox reaction, has a significant effect on electrochemical performance. Herein, annealing MXene under hydrogen was employed for removing-F and turning-OH to-O terminations. We demonstrate that it improves the kinetics of Li-ion transport between the electrolyte and electrode. As a result, a lower interfacial charge transfer impedance was obtained. The electrochemical measurement exhibited that a nearly 2-fold increase of specific capacity was achieved for the annealed MXene.
基金C.Z.is grateful for the financial support from the National Natural Science Foundation of China(21722205 and 21971173)the Project of Scientific and Technologic Infrastructure of Suzhou(SZS201905)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Aliphatic alcohols and amides are highly valued,ubiquitous chemicals in synthetic chemistry.Radical-promoted regioselective functionalization of unactivated C(sp^(3))–H bonds offers an atom and step economic manner for direct transformation of aliphatic alcohols and amides,especially structural elaboration of complex natural products and bioactive molecules without de novo synthesis.Despite the rapid growth of hydrogen atom transfer(HAT)processes mediated by O-or N-centered radicals generated from prefunctionalized precursors of alcohols and amides in the past few years,exploration of remote C(sp^(3))–H functionalization via HAT mediated by unprotected alcohols or amides lags behind,due to the difficult homolysis of O–H and N–H bonds with high bond-dissociation energies(BDEs).In this minireview,the recent advances in regioselective C(sp^(3))–H functionalization mediated by unprotected alcohols and amides are summarized.
基金supported by National Natural Science Foundation of China(Nos.11175126,11375126,11435009,11505123)the National Magnetic Confinement Fusion Program of China(Nos.2014GB106005,2010GB106000)+1 种基金a project funded by China Postdoctoral Science Foundationa project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘A high growth rate fabrication of diamond-like carbon（DLC）films at room temperature was achieved by helicon wave plasma chemical vapor deposition（HWP-CVD）using Ar/CH4gas mixtures.The microstructure and morphology of the films were characterized by Raman spectroscopy and scanning electron microscopy.The diagnosis of plasma excited by a helicon wave was measured by optical emission spectroscopy and a Langmuir probe.The mechanism of high growth rate fabrication for DLC films by HWP-CVD has been discussed.The growth rate of the DLC films reaches a maximum value of 54μm h^-1at the CH4flow rate of 85 sccm,which is attributed to the higher plasma density during the helicon wave plasma discharge.The CH and Hαradicals play an important role in the growth of DLC films.The results show that the Hαradicals are beneficial to the formation and stabilization of C=C bond from sp^2to sp^3.
