A homochrial manganese(Ⅲ) complex(1) derived from chiral salen ligand(1 R,2 R)-(-)-1,2-diphenylethane-1,2-diamine-N,N?-bicarboxyl-salicylidene) has been synthesized through solvothermal procedure and charac...A homochrial manganese(Ⅲ) complex(1) derived from chiral salen ligand(1 R,2 R)-(-)-1,2-diphenylethane-1,2-diamine-N,N?-bicarboxyl-salicylidene) has been synthesized through solvothermal procedure and characterized by IR,elemental analysis,TGA,circular dichroism(CD),powder and single-crystal X-ray crystallography.It crystallizes in orthorhombic,space group P212121 with a = 9.108(3),b = 16.431(5),c = 26.531(6) A,V = 3970.4(19) A^3,Z = 4,Dc = 1.248 g/cm^3,F(000) = 1568,Mr = 745.73,μ = 0.383 mm^-1,the final GOOF = 0.957,R = 0.0631 and wR = 0.1079 for 13250 observed reflections with I 〉 2σ(I).The coordination polymer 1 possesses a 1 D infinite zigzag chain architecture constructed by the dicarboxyl-functionalized metallosalen ligand(Mn-salen),and the polymeric chains are further assembled into a 3D supramolecular network structure via strong intermolecular hydrogen bonding interactions between adjacent zigzag chains.As a heterogeneous catalyst,1 was used as an efficient heterogeneous catalyst for the asymmetric olefin epoxidation.展开更多
Selective reduction of readily available N-heteroarenes is important in both organic synthesis and chemical biology.Herein,we describe ligand-controlled regiodivergent hydroboration of quinolines using well-defined am...Selective reduction of readily available N-heteroarenes is important in both organic synthesis and chemical biology.Herein,we describe ligand-controlled regiodivergent hydroboration of quinolines using well-defined amido-manganese catalysts,with an emphasis on the rarely reported 1,4-regioselectivity.Mechanistic studies showed that 1,2-hydroboration of quinoline was kinetically favorable and reversible,whereas 1,4-hydroboration was under thermodynamic control.Using a 1-methyimidazolebased pincer amido-manganese complex as the catalyst,cooperative C-H…N andπ…πnoncovalent interactions between the 1-methyimidazole moiety and quinoline substrates enabled kinetic accessibility of 1,4-hydroboration,giving thermodynamically favored 1,4-hydroborated quinolines as the major products.On this basis,Mn-catalyzed 1,4-hydroboration of a series of substituted quinolines proceeded smoothly in high yields.A high turnover number of 2500 was achieved in this reaction with satisfying regioselectivity.This transformation could be further applied to the C3-selective functionalization of quinolines,highlighting the synthetic utility of this methodology.In contrast,using a pyridine-based pincer amido-manganese complex as the catalyst,which lacked the C-H…N interaction,the free-energy barrier for 1,4-hydroboration significantly increased through a N-B…N interaction between the“HMn-NB”species and quinoline,resulting in the kinetically favored 1,2-hydroboration product with excellent regioselectivity.展开更多
A series of N-base appended corroles and their manganese complexes were synthesized and their binding constants with three different nitrogenous ligands, triethylamine, N-methylimidazole and pyridine, were evaluated b...A series of N-base appended corroles and their manganese complexes were synthesized and their binding constants with three different nitrogenous ligands, triethylamine, N-methylimidazole and pyridine, were evaluated by spectroscopy. Kinetic studies indicated that the presence of appended N- donor ligands may cause a significant enhancement of the rate of oxygen atom transfers (OAT) from (oxo)manganese(V) corrole to alkene, and the stronger axial ligand binding has impact on the rate of the oxidation reaction. Turnover frequency (TOF) for the catalytic oxidation of alkenes by appended manganese corroles varies with the following ligand order: acetamido 〈 pyridyl 〈 imidazolyl. The influence of the external axial ligands on the catalytic epoxidation was investigated by using appended acetamido manganese corrole as catalyst, with the results revealing that N-methylimidazole gave the best enhancement on the yields of total oxidation products among the investigated nitrogenous ligands.展开更多
The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable c...The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable chemicals,is highly desirable.Herein,we report a novel manganese-catalyzed dehydrogenative cyclization of methanol as a formaldehyde surrogate with a variety of dinucleophiles for facile synthesis of N-heterocycles.The in situ generated formaldehyde via catalytic methanol dehydrogenation can be selectively trapped by diverse dinucleophiles to avoid several possible side reactions.The utilty of this transformation is further highlighted by its successful appliation to the synthesis of 13C-labeled N-heterocycles using 13CH_(3)OH as a readily accessible 13C-isotope reagent.展开更多
Conventional reactive sites of ketones with aldehydes lie on the carbonyl andα-carbon positions,which lead to a wide range of classic reactions such as pinacol-coupling and aldol-type condensations.Herein,an unpreced...Conventional reactive sites of ketones with aldehydes lie on the carbonyl andα-carbon positions,which lead to a wide range of classic reactions such as pinacol-coupling and aldol-type condensations.Herein,an unprecedented reactive site of aromatic ketones toward aldehydes has been revealed by using earth-abundant manganese catalysis,which enabled the first deoxygenative[3+2]annulations of ketones and aldehydes through C–H activation affording isobenzofuran derivatives.Mechanistic studies give hints on the dual role of triphenylborane additive in the reaction,that is,promoting C–H activation as a transmetalation reagent and activating aldehydes as a Lewis acid.展开更多
Great efforts have been made in investigating the neurotoxicity of dopamine(DA)in the presence of manganous ions.In contrast,here,we probe the possibility of DA-based cancer chemotherapy by leveraging intratumoral red...Great efforts have been made in investigating the neurotoxicity of dopamine(DA)in the presence of manganous ions.In contrast,here,we probe the possibility of DA-based cancer chemotherapy by leveraging intratumoral redox reactions of DA for producing cytotoxic species in situ.For this purpose,we have constructed a Mn-engineered,DA-loaded nanomedicine.Based on the unique size effect of the nanocarrier,this nanomedicine will not enter the central nervous system but can effectively accumulate in the tumor region,after which the nanocarrier can degrade to release Mn^(2+)and DA in response to the mild acidic intracelluar microenvironment of cancer cells.DA can chelate Mn^(2+)to form a binary coordination complex,where the strong metal-ligand interaction significantly promotes electron delocalization and elevates the reducibility of Mn center,favoring two sequential one-electron oxygen reduction reactions forming H_(2)O_(2),which can be further converted into highly oxidizing ·OH under the cocatalysis by Mn^(2+)and intracellular Fe^(2+).Additionally,as a twoelectron oxidation product of DA ligand,DA-oquinone is potent in exhausting cellular sulfhydryl and depleting reduced glutathione,inhibiting the intrinsic antioxidative mechanism of cancer cells,finally triggering severe oxidative damages in a synergistic manner.It is expected that such a strategy of nanotechnology-mediated metal-ligand coordination and subsequent nontoxicity-to-toxicity transition of DA in tumor may provide a promising prospect for future chemotherapy design.展开更多
基金supported by NSFC-21371119,21431004,21401128,21522104 and 21620102001the National Key Basic Research Program of China(No.2014CB932102 and 2016YFA0203400)the Shanghai“Eastern Scholar”Program
文摘A homochrial manganese(Ⅲ) complex(1) derived from chiral salen ligand(1 R,2 R)-(-)-1,2-diphenylethane-1,2-diamine-N,N?-bicarboxyl-salicylidene) has been synthesized through solvothermal procedure and characterized by IR,elemental analysis,TGA,circular dichroism(CD),powder and single-crystal X-ray crystallography.It crystallizes in orthorhombic,space group P212121 with a = 9.108(3),b = 16.431(5),c = 26.531(6) A,V = 3970.4(19) A^3,Z = 4,Dc = 1.248 g/cm^3,F(000) = 1568,Mr = 745.73,μ = 0.383 mm^-1,the final GOOF = 0.957,R = 0.0631 and wR = 0.1079 for 13250 observed reflections with I 〉 2σ(I).The coordination polymer 1 possesses a 1 D infinite zigzag chain architecture constructed by the dicarboxyl-functionalized metallosalen ligand(Mn-salen),and the polymeric chains are further assembled into a 3D supramolecular network structure via strong intermolecular hydrogen bonding interactions between adjacent zigzag chains.As a heterogeneous catalyst,1 was used as an efficient heterogeneous catalyst for the asymmetric olefin epoxidation.
基金the National Key R&D Program of China(grant no.2021YFF0701600)the National Natural Science Foundation of China(grant no.22225103)Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs,Shanghai Jiao Tong University,and the China Postdoctoral Science Foundation(grant nos.2020M680021 and 2021T140366),which was greatly appreciated.
文摘Selective reduction of readily available N-heteroarenes is important in both organic synthesis and chemical biology.Herein,we describe ligand-controlled regiodivergent hydroboration of quinolines using well-defined amido-manganese catalysts,with an emphasis on the rarely reported 1,4-regioselectivity.Mechanistic studies showed that 1,2-hydroboration of quinoline was kinetically favorable and reversible,whereas 1,4-hydroboration was under thermodynamic control.Using a 1-methyimidazolebased pincer amido-manganese complex as the catalyst,cooperative C-H…N andπ…πnoncovalent interactions between the 1-methyimidazole moiety and quinoline substrates enabled kinetic accessibility of 1,4-hydroboration,giving thermodynamically favored 1,4-hydroborated quinolines as the major products.On this basis,Mn-catalyzed 1,4-hydroboration of a series of substituted quinolines proceeded smoothly in high yields.A high turnover number of 2500 was achieved in this reaction with satisfying regioselectivity.This transformation could be further applied to the C3-selective functionalization of quinolines,highlighting the synthetic utility of this methodology.In contrast,using a pyridine-based pincer amido-manganese complex as the catalyst,which lacked the C-H…N interaction,the free-energy barrier for 1,4-hydroboration significantly increased through a N-B…N interaction between the“HMn-NB”species and quinoline,resulting in the kinetically favored 1,2-hydroboration product with excellent regioselectivity.
基金supported by National Natural Science Foundation of China(Nos.21171057,21371059)Research Grant Councilof Hong Kong under project HKUST6182/99pArea of Excellence Scheme(No.AoE/P-10/01)
文摘A series of N-base appended corroles and their manganese complexes were synthesized and their binding constants with three different nitrogenous ligands, triethylamine, N-methylimidazole and pyridine, were evaluated by spectroscopy. Kinetic studies indicated that the presence of appended N- donor ligands may cause a significant enhancement of the rate of oxygen atom transfers (OAT) from (oxo)manganese(V) corrole to alkene, and the stronger axial ligand binding has impact on the rate of the oxidation reaction. Turnover frequency (TOF) for the catalytic oxidation of alkenes by appended manganese corroles varies with the following ligand order: acetamido 〈 pyridyl 〈 imidazolyl. The influence of the external axial ligands on the catalytic epoxidation was investigated by using appended acetamido manganese corrole as catalyst, with the results revealing that N-methylimidazole gave the best enhancement on the yields of total oxidation products among the investigated nitrogenous ligands.
基金This project was supported by the National Natural Science Foundation of China(Nos.91845107 and 21822106)the Foundation of the Department of Education of Guangdong Province(2018KZDXM070 and 2021KTSCX140)。
文摘The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable chemicals,is highly desirable.Herein,we report a novel manganese-catalyzed dehydrogenative cyclization of methanol as a formaldehyde surrogate with a variety of dinucleophiles for facile synthesis of N-heterocycles.The in situ generated formaldehyde via catalytic methanol dehydrogenation can be selectively trapped by diverse dinucleophiles to avoid several possible side reactions.The utilty of this transformation is further highlighted by its successful appliation to the synthesis of 13C-labeled N-heterocycles using 13CH_(3)OH as a readily accessible 13C-isotope reagent.
基金support from the National Natural Science Foundation of China(21772202,21831008)Beijing Municipal Science&Technology Commission(project No.Z191100007219009)Beijing National Laboratory for Molecular Sciences(BNLMS-CXXM-201901)are gratefully acknowledged.
文摘Conventional reactive sites of ketones with aldehydes lie on the carbonyl andα-carbon positions,which lead to a wide range of classic reactions such as pinacol-coupling and aldol-type condensations.Herein,an unprecedented reactive site of aromatic ketones toward aldehydes has been revealed by using earth-abundant manganese catalysis,which enabled the first deoxygenative[3+2]annulations of ketones and aldehydes through C–H activation affording isobenzofuran derivatives.Mechanistic studies give hints on the dual role of triphenylborane additive in the reaction,that is,promoting C–H activation as a transmetalation reagent and activating aldehydes as a Lewis acid.
基金the National Natural Science Foundation of China(grant no.21835007)Key Research Program of Frontier Sciences,Chinese Academy of Sciences(grant no.ZDBS-LY-SLH029)Shanghai Municipal Government S&T Project(grant no.17JC1404701).
文摘Great efforts have been made in investigating the neurotoxicity of dopamine(DA)in the presence of manganous ions.In contrast,here,we probe the possibility of DA-based cancer chemotherapy by leveraging intratumoral redox reactions of DA for producing cytotoxic species in situ.For this purpose,we have constructed a Mn-engineered,DA-loaded nanomedicine.Based on the unique size effect of the nanocarrier,this nanomedicine will not enter the central nervous system but can effectively accumulate in the tumor region,after which the nanocarrier can degrade to release Mn^(2+)and DA in response to the mild acidic intracelluar microenvironment of cancer cells.DA can chelate Mn^(2+)to form a binary coordination complex,where the strong metal-ligand interaction significantly promotes electron delocalization and elevates the reducibility of Mn center,favoring two sequential one-electron oxygen reduction reactions forming H_(2)O_(2),which can be further converted into highly oxidizing ·OH under the cocatalysis by Mn^(2+)and intracellular Fe^(2+).Additionally,as a twoelectron oxidation product of DA ligand,DA-oquinone is potent in exhausting cellular sulfhydryl and depleting reduced glutathione,inhibiting the intrinsic antioxidative mechanism of cancer cells,finally triggering severe oxidative damages in a synergistic manner.It is expected that such a strategy of nanotechnology-mediated metal-ligand coordination and subsequent nontoxicity-to-toxicity transition of DA in tumor may provide a promising prospect for future chemotherapy design.