Attaining the selective oxidation of isochroman into isochromanone in a molecular oxygen(O_(2))environment without any additives,via a heterogeneous oxidation process,is highly desirable and challenging work.Herein,we...Attaining the selective oxidation of isochroman into isochromanone in a molecular oxygen(O_(2))environment without any additives,via a heterogeneous oxidation process,is highly desirable and challenging work.Herein,we prepare two mixed-addendum polyoxometalate-based coordination polymers of the general formula[H_(x)M_(1-x)(i-PrIm)_(4)][H_(2)N(CH_(3))_(2)]_(4)[HPMo_(8)V_(6)O_(42)](M=Co 1,Ni,2;i-PrIm=1-isopropyl-1H-imidazole).Needing no additives,they can catalyze the selective oxidation of isochroman to isochromanone with O_(2)as an oxidant,with yields of 91.5%(1)and 46.8%(2),respectively.Mechanistic studies indicate that the excellent performance of catalyst 1 is attributed to the synergistic operation of[Co(i-Pr-Im)_(4))]complex and PMo_(8)V_(6)unit,and that the catalytic reaction is a radical pathway involving superoxide radicals.Additionally,the catalyst 1 can be recycled and reused at least four times with uncompromised performance.These results provide fundamental guidelines for designing efficient and multi-site heterogeneous catalysts for the selective oxidation of benzyl C(sp^(3))-H bonds by activating O_(2).展开更多
The simulation of the coordination geometry and environment of the active metal center in metalloenzymes is highly valuable for activating O_(2)to oxidize inexpensive bulk chemicals into high-value-added fine chemical...The simulation of the coordination geometry and environment of the active metal center in metalloenzymes is highly valuable for activating O_(2)to oxidize inexpensive bulk chemicals into high-value-added fine chemicals.In this study,we have selected the inorganic ligand phosphovanadomolybdate(PMoV)and the auxiliary ligand N-butylimidazole(bIM),which possess a long flexible alkyl chain,to jointly stabilize two types of triangular bipyramidal cobalt-based enzymatic complexes(PMoV-Co).展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22171122 and 22201123)Liaoning Revitalization Talents Program(No.XLYC 2007130)+1 种基金Fundamental Research Project(No.LJ212410148038)of the Educational Department of Liaoning ProvinceTalent Scientific Research Fund of Liaoning Petrochemical University(No.2016XJJL–019)。
文摘Attaining the selective oxidation of isochroman into isochromanone in a molecular oxygen(O_(2))environment without any additives,via a heterogeneous oxidation process,is highly desirable and challenging work.Herein,we prepare two mixed-addendum polyoxometalate-based coordination polymers of the general formula[H_(x)M_(1-x)(i-PrIm)_(4)][H_(2)N(CH_(3))_(2)]_(4)[HPMo_(8)V_(6)O_(42)](M=Co 1,Ni,2;i-PrIm=1-isopropyl-1H-imidazole).Needing no additives,they can catalyze the selective oxidation of isochroman to isochromanone with O_(2)as an oxidant,with yields of 91.5%(1)and 46.8%(2),respectively.Mechanistic studies indicate that the excellent performance of catalyst 1 is attributed to the synergistic operation of[Co(i-Pr-Im)_(4))]complex and PMo_(8)V_(6)unit,and that the catalytic reaction is a radical pathway involving superoxide radicals.Additionally,the catalyst 1 can be recycled and reused at least four times with uncompromised performance.These results provide fundamental guidelines for designing efficient and multi-site heterogeneous catalysts for the selective oxidation of benzyl C(sp^(3))-H bonds by activating O_(2).
基金financially supported by the National Natural Science Foundation of China(22171122 and 22201123)the Liaoning Revitalization Talents Program(XLYC2007130)the Talent Scientific Research Fund of Liaoning Petrochemical University(2016XJJL–019).
文摘The simulation of the coordination geometry and environment of the active metal center in metalloenzymes is highly valuable for activating O_(2)to oxidize inexpensive bulk chemicals into high-value-added fine chemicals.In this study,we have selected the inorganic ligand phosphovanadomolybdate(PMoV)and the auxiliary ligand N-butylimidazole(bIM),which possess a long flexible alkyl chain,to jointly stabilize two types of triangular bipyramidal cobalt-based enzymatic complexes(PMoV-Co).
