This study proposes two different methods of photocatalytic-controlled and visible light-induced selective oxidation of pyridiniums with air as the terminal oxidant.The key to these transformations is to choose the ap...This study proposes two different methods of photocatalytic-controlled and visible light-induced selective oxidation of pyridiniums with air as the terminal oxidant.The key to these transformations is to choose the appropriate light source and photocatalyst.Pyridiniums are successfully converted into pyrroles through oxygen-mediated cycloaddition,proton-coupled electron transfer(PCET),pyridine ring opening,and recyclization.The other route is that pyridiniums selectively form 4-carbonyl pyridines through free radical rearrangement/aerobic oxidation under the catalysis of cobalt(Ⅱ).展开更多
Using fewer catalysts to promote the chemical conversion of more substrates is the dream synthesis pursued by synthetic chemists.Achieving highly selective reactions using trace amounts(<1 ppm)of catalysts is rare ...Using fewer catalysts to promote the chemical conversion of more substrates is the dream synthesis pursued by synthetic chemists.Achieving highly selective reactions using trace amounts(<1 ppm)of catalysts is rare and has undoubted practical value.Herein,we designed and synthesized a single-atom Pd-metalated porous organic ligand polymer,denoted as Pd1@POL,and used the polymer to realize the regioselective hydrosilylation of allenes(Pd loading was as low as 0.98 ppm).The synergistic effect of the dispersed catalytic active sites in the catalyst and supports with ligand regulation function can directionally realize the formation of specifically configured hydrosilylation products.The as-fabricated single-atom catalyst(SAC;i.e.,Pd1@POL-5)showed an amazing catalytic efficiency and selectivity for hydrosilylation of allene(turnover number was up to 772,358,which was 200 times higher than previously recorded,and regioselectivity>100:1).The catalyst could be recycled numerous times in a continuous flow system without reductions in activity and selectivity.This work demonstrated the application prospect of the SAC in the synthesis of complex organic compounds and trace amount catalysis,which can lay the foundation for its large-scale and industrialized application in drug synthesis and other fields.展开更多
N-heterocyclic carbene(NHC) is a potent organic small-molecule catalyst.However,its high synthetic price and frequent use in combination with excess oxidants have limited its utilization in industrial production.We de...N-heterocyclic carbene(NHC) is a potent organic small-molecule catalyst.However,its high synthetic price and frequent use in combination with excess oxidants have limited its utilization in industrial production.We designed and synthesized a porous organic polymer with NHC as the core structure to solve the above problems.The catalytic performance of the polymer was tested in this work.The polymer can successfully catalyze the cycloaddition reaction of aldehyde and ethyl isocyanoacetate under electro-oxidation.The results showed that the polymer catalyst can be recycled and had higher catalytic activity than homogeneous NHC.The developed catalytic system(organic electrochemistry and NHC polymer) solves the existing problems of NHC catalysis and provides a reference for the development of new green catalytic systems.展开更多
Correction for‘Electrochemically-mediated C-H functionalization of allenes and 1,3-dicarbonyl compounds to construct tetrasubstituted furans’by Mu-Xue He et al.,Org.Chem.Front.,2022,DOI:10.1039/d1qo01458g.One of the...Correction for‘Electrochemically-mediated C-H functionalization of allenes and 1,3-dicarbonyl compounds to construct tetrasubstituted furans’by Mu-Xue He et al.,Org.Chem.Front.,2022,DOI:10.1039/d1qo01458g.One of the author names(Hai-Tao Tang)was spelled incorrectly in the published article;the corrected version is shown here.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.展开更多
基金This work was supported by the National Natural Science Foundation of China(22061003,21861006)the Guangxi Natural Science Foundation of China(2016GXNSFEA380001,2019GXNSFAA245027)+2 种基金the Guangxi Key R&D Program(AB18221005)the Science and Technology Major Project of Guangxi(AA17204058-21)Guangxi Science and Technology Base and Special Talents(guike AD19110027).
文摘This study proposes two different methods of photocatalytic-controlled and visible light-induced selective oxidation of pyridiniums with air as the terminal oxidant.The key to these transformations is to choose the appropriate light source and photocatalyst.Pyridiniums are successfully converted into pyrroles through oxygen-mediated cycloaddition,proton-coupled electron transfer(PCET),pyridine ring opening,and recyclization.The other route is that pyridiniums selectively form 4-carbonyl pyridines through free radical rearrangement/aerobic oxidation under the catalysis of cobalt(Ⅱ).
基金the Guangxi Natural Science Foundation of China(No.2021GXNSFFA220005)the central government guides local science and technology development fund projects(No.guike ZY21195014)+1 种基金the National Natural Science Foundation of China(Nos.22061003 and 22161008)the Opening Project of Hunan Engineering Laboratory for Analyse and Drugs Development of Ethnomedicine in Wuling Mountain(No.hgxy2101)for financial support.
文摘Using fewer catalysts to promote the chemical conversion of more substrates is the dream synthesis pursued by synthetic chemists.Achieving highly selective reactions using trace amounts(<1 ppm)of catalysts is rare and has undoubted practical value.Herein,we designed and synthesized a single-atom Pd-metalated porous organic ligand polymer,denoted as Pd1@POL,and used the polymer to realize the regioselective hydrosilylation of allenes(Pd loading was as low as 0.98 ppm).The synergistic effect of the dispersed catalytic active sites in the catalyst and supports with ligand regulation function can directionally realize the formation of specifically configured hydrosilylation products.The as-fabricated single-atom catalyst(SAC;i.e.,Pd1@POL-5)showed an amazing catalytic efficiency and selectivity for hydrosilylation of allene(turnover number was up to 772,358,which was 200 times higher than previously recorded,and regioselectivity>100:1).The catalyst could be recycled numerous times in a continuous flow system without reductions in activity and selectivity.This work demonstrated the application prospect of the SAC in the synthesis of complex organic compounds and trace amount catalysis,which can lay the foundation for its large-scale and industrialized application in drug synthesis and other fields.
基金supported by the Guangxi Natural Science Foundation of China (2021GXNSFFA220005)the Middle-Aged and Young Teachers’ Basic Scientific Research Ability Improvement Project of Guangxi (RZ1900005748)+1 种基金the Central Government Guides Local Science and Technology Development Fund Projects (guike ZY21195014)the National Natural Science Foundation of China (22061003,22161008)
文摘N-heterocyclic carbene(NHC) is a potent organic small-molecule catalyst.However,its high synthetic price and frequent use in combination with excess oxidants have limited its utilization in industrial production.We designed and synthesized a porous organic polymer with NHC as the core structure to solve the above problems.The catalytic performance of the polymer was tested in this work.The polymer can successfully catalyze the cycloaddition reaction of aldehyde and ethyl isocyanoacetate under electro-oxidation.The results showed that the polymer catalyst can be recycled and had higher catalytic activity than homogeneous NHC.The developed catalytic system(organic electrochemistry and NHC polymer) solves the existing problems of NHC catalysis and provides a reference for the development of new green catalytic systems.
文摘Correction for‘Electrochemically-mediated C-H functionalization of allenes and 1,3-dicarbonyl compounds to construct tetrasubstituted furans’by Mu-Xue He et al.,Org.Chem.Front.,2022,DOI:10.1039/d1qo01458g.One of the author names(Hai-Tao Tang)was spelled incorrectly in the published article;the corrected version is shown here.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.
