The oxidation of organic compounds by sulfonated porous carbon and H2O2 was studied at room temperature. Alkyl and aryl sulfides were oxidized to the corresponding sulfoxides or sulfones in excellent yields. Secondary...The oxidation of organic compounds by sulfonated porous carbon and H2O2 was studied at room temperature. Alkyl and aryl sulfides were oxidized to the corresponding sulfoxides or sulfones in excellent yields. Secondary alcohols were also converted to the corresponding esters/lactones and aldehydes to methyl esters in good yields. Moreover,aliphatic tertiary amines and substituted pyridines were oxidized to N-oxides.展开更多
Synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride in the presence of a catalytic amount of iodine at room temperature under solvent-free conditions is described. Mild reaction conditions, eas...Synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride in the presence of a catalytic amount of iodine at room temperature under solvent-free conditions is described. Mild reaction conditions, easy workup, high yield, and easily available catalyst are important features of this method.展开更多
The asymmetric oxidation of sulfides catalyzed by WO3 and 30% H2O2 in the presence of salan as chiral ligands under heterogeneous conditions is described. The reaction system is very easily to be operated. Mild to hig...The asymmetric oxidation of sulfides catalyzed by WO3 and 30% H2O2 in the presence of salan as chiral ligands under heterogeneous conditions is described. The reaction system is very easily to be operated. Mild to high chemical yields and moderate enantioselectivities were obtained.展开更多
The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted.The sulfoxides and sulfones could be obtained by simply switching the reaction media,i.e.,bis(2-butoxyethyl)ethe...The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted.The sulfoxides and sulfones could be obtained by simply switching the reaction media,i.e.,bis(2-butoxyethyl)ether(BBE)or poly(ethylene glycol)dimethyl ether(PEGDME).The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents.This strategy represents an economic and eco-friendly method that could find potential applications.展开更多
Chloroalkanes are important building blocks in the synthesis,but their use in redox chemistry is limited by their negative reduction potentials.Electrosynthesis can precisely control the reaction energy just by adjust...Chloroalkanes are important building blocks in the synthesis,but their use in redox chemistry is limited by their negative reduction potentials.Electrosynthesis can precisely control the reaction energy just by adjusting the current or voltage to achieve the selectivity of regulation.In this study,the consecutively paired electrolyticmediated controllable radical cross-coupling of thiophenols with dichloromethane was developed to deliver the dithioacetals,sulfides,and sulfoxides in the absence of electrochemical mediator conditions.It features broad substrate scope,simple operation,gram-scale synthesis,and is eco-friendly.Mechanistic studies reveal that this electrochemical reaction is radical-induced cross-coupling of thiophenols with dichloromethane.展开更多
Visible light photocatalysis of covalent organic frameworks(COFs) has made significant progress in recent years. Benzotrithiophene(BTT), a planar, electron-rich building block, turns out to be foundational in assembli...Visible light photocatalysis of covalent organic frameworks(COFs) has made significant progress in recent years. Benzotrithiophene(BTT), a planar, electron-rich building block, turns out to be foundational in assembling COFs in which the fullπ-conjugation of BTT is essential to facilitate electron transfer. Herein, a sp~2 carbon-conjugated COF, namely BTT-sp~2c-COF, is assembled from benzo[1,2-b:3,4-b′:5,6-b′′]trithiophene-2,5,8-tricarbaldehyde and [1,1′:4′,1′′-terphenyl]-4,4′′-dicarbonitrile towards photocatalysis. More importantly, TEMPO(2,2,6,6-tetramethylpiperidin-1-yl)oxyl, 1 mol%) could considerably accelerate the selective oxidation of organic sulfides with O_(2) over BTT-sp~2c-COF. TEMPO mediates hole transfer between BTT-sp~2c-COF and organic sulfides, and O-atoms are incorporated into sulfoxides via an electron transfer pathway. Merging BTT-sp~2c-COF photocatalysis with TEMPO generally applies to transforming organic sulfides into sulfoxides. This work implies the full π-conjugation of electron-rich building blocks into COFs is a viable strategy for selective visible light photocatalysis.展开更多
基金Supported by the Malek-Ashtar University of Technology
文摘The oxidation of organic compounds by sulfonated porous carbon and H2O2 was studied at room temperature. Alkyl and aryl sulfides were oxidized to the corresponding sulfoxides or sulfones in excellent yields. Secondary alcohols were also converted to the corresponding esters/lactones and aldehydes to methyl esters in good yields. Moreover,aliphatic tertiary amines and substituted pyridines were oxidized to N-oxides.
文摘Synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride in the presence of a catalytic amount of iodine at room temperature under solvent-free conditions is described. Mild reaction conditions, easy workup, high yield, and easily available catalyst are important features of this method.
基金National Natural Science Foundation of China(No.20102002,20472028)Science Foundation of Jiangsu Province for their financial support(No.20332050).
文摘The asymmetric oxidation of sulfides catalyzed by WO3 and 30% H2O2 in the presence of salan as chiral ligands under heterogeneous conditions is described. The reaction system is very easily to be operated. Mild to high chemical yields and moderate enantioselectivities were obtained.
文摘The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted.The sulfoxides and sulfones could be obtained by simply switching the reaction media,i.e.,bis(2-butoxyethyl)ether(BBE)or poly(ethylene glycol)dimethyl ether(PEGDME).The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents.This strategy represents an economic and eco-friendly method that could find potential applications.
基金This work is supported by the National Natural Science Foundation of China(No.21902083)the Natural Science Foundation of Shandong Province(No.ZR2020QB130)This work is also supported by the Talent Program Foundation of Qufu Normal University(Nos.6132 and 6125).
文摘Chloroalkanes are important building blocks in the synthesis,but their use in redox chemistry is limited by their negative reduction potentials.Electrosynthesis can precisely control the reaction energy just by adjusting the current or voltage to achieve the selectivity of regulation.In this study,the consecutively paired electrolyticmediated controllable radical cross-coupling of thiophenols with dichloromethane was developed to deliver the dithioacetals,sulfides,and sulfoxides in the absence of electrochemical mediator conditions.It features broad substrate scope,simple operation,gram-scale synthesis,and is eco-friendly.Mechanistic studies reveal that this electrochemical reaction is radical-induced cross-coupling of thiophenols with dichloromethane.
基金supported by the National Natural Science Foundation of China (22072108)。
文摘Visible light photocatalysis of covalent organic frameworks(COFs) has made significant progress in recent years. Benzotrithiophene(BTT), a planar, electron-rich building block, turns out to be foundational in assembling COFs in which the fullπ-conjugation of BTT is essential to facilitate electron transfer. Herein, a sp~2 carbon-conjugated COF, namely BTT-sp~2c-COF, is assembled from benzo[1,2-b:3,4-b′:5,6-b′′]trithiophene-2,5,8-tricarbaldehyde and [1,1′:4′,1′′-terphenyl]-4,4′′-dicarbonitrile towards photocatalysis. More importantly, TEMPO(2,2,6,6-tetramethylpiperidin-1-yl)oxyl, 1 mol%) could considerably accelerate the selective oxidation of organic sulfides with O_(2) over BTT-sp~2c-COF. TEMPO mediates hole transfer between BTT-sp~2c-COF and organic sulfides, and O-atoms are incorporated into sulfoxides via an electron transfer pathway. Merging BTT-sp~2c-COF photocatalysis with TEMPO generally applies to transforming organic sulfides into sulfoxides. This work implies the full π-conjugation of electron-rich building blocks into COFs is a viable strategy for selective visible light photocatalysis.
