We developed a simple and efficient Cu（II）-catalyzed ligand-free oxidation of diarylmethanes and secondary alcohols using 70% ten-butyl hydroperoxide （TBHP） in water. A series of diarylmethanes were directly oxidi...We developed a simple and efficient Cu（II）-catalyzed ligand-free oxidation of diarylmethanes and secondary alcohols using 70% ten-butyl hydroperoxide （TBHP） in water. A series of diarylmethanes were directly oxidized into diaryl ketones in 67%--98% yields. Additionally, various secondary alcohols were also transformed into the desired products in 48%--98% yields. Importantly, the catalytic system in the absence of any organic solvent, surfactant, or phase transfer agent, had a wide substrate scope and a high tolerance for various functional groups.展开更多
The low-efficiency CO_(2) uptake capacity and insufficient photogenerated exciton dissociation of current metal halide perovskite(MHP)nanocrystals with end-capping ligands extremely restrict their application in the f...The low-efficiency CO_(2) uptake capacity and insufficient photogenerated exciton dissociation of current metal halide perovskite(MHP)nanocrystals with end-capping ligands extremely restrict their application in the field of artificial photosynthesis.Herein,we demonstrate that ligand-free CsPbBr_(3) with calliandralike nanostructure(LF-CPB CL)can be synthesized easily through a ligand-free seed-assisted dissolutionrecrystallization growth process,exhibiting significantly enhanced CO_(2) uptake capacity.More specifically,the abundant surface bromine(Br)vacancies in ligand-free MHP materials are demonstrated to be beneficial to photogenerated carrier separation.The electron consumption rate of LF-CPB CL for photocatalytic CO_(2) reduction increases 7 and 20 times over those of traditional ligand-capping CsPbBr_(3)nanocrystal(L-CPB NC)and bulk CsPbBr_(3),respectively.Moreover,the absence of ligand hindrance can facilitate the interfacial electronic coupling between LF-CPB CL and tetra(4-carboxyphenyl)porphyrin iron(Ⅲ)chloride(Fe-TCPP)cocatalyst,bringing forth significantly accelerated interfacial charge separation.The LF-CPB CL/Fe-TCPP exhibits a total electron consumption rate of 145.6μmol g^(-1) h^(-1) for CO_(2)photoreduction coupled with water oxidation which is over 14 times higher than that of L-CPB NC/FeTCPP.展开更多
An efficient copper-catalyzed decarboxylative hydroboration of phenylpropiolic acids with bis（pinacolato）diboron was developed, affording b-vinylboronates as the only products in high yields. Extra hydrogen sources ...An efficient copper-catalyzed decarboxylative hydroboration of phenylpropiolic acids with bis（pinacolato）diboron was developed, affording b-vinylboronates as the only products in high yields. Extra hydrogen sources such as methanol are not needed in this catalytic system. This reaction could be performed successfully under ligand- and base-free conditions. It demonstrated that phenylpropiolic acids can be employed as alkyne synthons in the hydroboration reaction and exhibited good reactivity and higher selectivity than terminal alkynes.展开更多
Symmetrical diynes were synthesized by ligand-free copper-catalyzed homocoupling reaction of 1,1-dibromo-1- alkenes using a DBU/DMSO system at room temperature in good to excellent yields.
Carbon-supported copper catalyst was prepared for the first time in one-step with copper nitrate and corn stalk through calcination under different temperatures. Uniformly dispersed nanoparticles were obtained and wer...Carbon-supported copper catalyst was prepared for the first time in one-step with copper nitrate and corn stalk through calcination under different temperatures. Uniformly dispersed nanoparticles were obtained and were identified to be Cu（0） and Cu（Ⅰ） in XRD patterns. Excellent catalytic activity and selectivity were achieved in the N-arylation of pyrazole under ligand and protection gas free conditions. About90.4% of product yield was achieved with only 0.5 mol% of copper catalyst（Cu-C-300）, which was considerably more efficient than previous reports. XPS results suggested that the N-arylation of pyrazole activity was closely related to the surface Cu（Ⅰ） species.展开更多
The non-toxic and magnetically separable nano-CuFeOcatalyzed synthesis of symmetrical aryl sulfides by the reaction of thiourea with a wide variety of aryl halides,including aryl chlorides has been reported.Excellent ...The non-toxic and magnetically separable nano-CuFeOcatalyzed synthesis of symmetrical aryl sulfides by the reaction of thiourea with a wide variety of aryl halides,including aryl chlorides has been reported.Excellent yields of products have been obtained under ligand-free conditions and without the use of any expensive catalyst,such as palladium.展开更多
A simple and efficient protocol for Fe/Cu cocatalyzed oxidative homocoupling reaction of terminal alkynes to symmetrical 1,4-disubstituted-l,3-diynes was presented. The results showed that both CuBr and FeC13 played e...A simple and efficient protocol for Fe/Cu cocatalyzed oxidative homocoupling reaction of terminal alkynes to symmetrical 1,4-disubstituted-l,3-diynes was presented. The results showed that both CuBr and FeC13 played erucial roles in the reaction. It is noteworthy that this protocol employs mild, efficient, aerobic and ligand free conditions. The alkynes, including aromatic, heteroaromatic and aliphatic alkynes, were transformed into the corresponding 1,3-diynes in good to excellent yields.展开更多
The boron trifluoride induced Suzuki-Miyaura cross-coupling of aryltriazenes with arylboronic acids catalyzed by Pd（OAc）2 without added ligands has been achieved for the first time. The reactions performed at room t...The boron trifluoride induced Suzuki-Miyaura cross-coupling of aryltriazenes with arylboronic acids catalyzed by Pd（OAc）2 without added ligands has been achieved for the first time. The reactions performed at room temperature under an argon atmosphere give biaryls in good to excellent yields. It is noteworthy that the reactions were conducted under mild and ligand-free conditions.展开更多
The matrix assembly cluster source(MACS)represents a bridge between conventional instruments for cluster beam deposition(CBD)and thelevel of industrial production.The method is based on Ar^+ion sputtering of a pre-con...The matrix assembly cluster source(MACS)represents a bridge between conventional instruments for cluster beam deposition(CBD)and thelevel of industrial production.The method is based on Ar^+ion sputtering of a pre-condensed Ar-M matrix(where M,is typically a metal such asAg).Each Ar^+ion produces a collision cascade and thus the formation of metal clusters is in the matrix,which are then sputtered out.Here wepresent an experimental and computational investigation of the cluster emission process,specifically its dependence on the Ar^+ion angle of in cidence and the cluster emission angle.We find the in cide nee angle strongly in flue nces the emerging cluster flux,which is assigned to thespatial location of the deposited primary ion energy relative to the cluster into the matrix.We also found an approximately constant anglebetween the incident ion beam and the peak in the emitted cluster distribution,with value between 99°and 109°.展开更多
The synthesis of N-cyclohexyl carbamate-attached fluorene-alt-phenylene copolymer(PFPNCC)and the use of PFPNCC as a“ligand-free”fluorescent chemosensor for Cu(Ⅱ)are described.Addition of Cu(Ⅱ)can efficiently quenc...The synthesis of N-cyclohexyl carbamate-attached fluorene-alt-phenylene copolymer(PFPNCC)and the use of PFPNCC as a“ligand-free”fluorescent chemosensor for Cu(Ⅱ)are described.Addition of Cu(Ⅱ)can efficiently quench the fluorescence of PFPNCC in nucleophilic solvents such as DMF and DMSO,but not in low nucleophilic solvents such as 1,4-dioxane and THF.Ultraviolet-visible spectra of the mixture of the conjugated polymer and Cu(Ⅱ)indicate the presence of a reduced Cu(Ⅰ)ion in the solution.Furthermore,fluorescence recovery of PFPNCC observed at low temperature suggests that the quenching and reducing mechanism is most probably due to a photo-induced electron transfer from excited PFPNCC to Cu(Ⅱ).Our findings provide a novel strategy for highly selective conjugated polymer-based chemosensors for various target analytes,albeit“ligand-free”.展开更多
基金We gratefully acknowledge financial support of this work by the National Natural Science Foundation of China （No. 21563025）, Shihezi University Training Programme for Distinguished Youth Scholars （No. 2014ZRKXJQ05）, and Start-Up Foundation for Young Scientists of Shihezi University （RCZX201408）.
文摘We developed a simple and efficient Cu（II）-catalyzed ligand-free oxidation of diarylmethanes and secondary alcohols using 70% ten-butyl hydroperoxide （TBHP） in water. A series of diarylmethanes were directly oxidized into diaryl ketones in 67%--98% yields. Additionally, various secondary alcohols were also transformed into the desired products in 48%--98% yields. Importantly, the catalytic system in the absence of any organic solvent, surfactant, or phase transfer agent, had a wide substrate scope and a high tolerance for various functional groups.
基金supported by the National Natural Science Foundation of China (21276043)the Ministry of Education Program for New Century Excellent Talents in University (NCET-10-0283)~~
基金supported by the National Natural Science Foundation of China(22071191)the Key Research and Development Projects of Shaanxi Province(2021GXLH-Z-022)+3 种基金the Fundamental Research Funds for the Central Universitiesthe Key Scientific and Technological Innovation Team of Shaanxi Province(2020TD-001)Liu K acknowledges China Postdoctoral Science Foundation(2019TQ0249)the Natural Science Basic Research Plan in Shaanxi Province(2022JQ-100)。
基金financially supported by the Natural Science Foundation of Tianjin City(17JCJQJC43800)the National Key R&D Program of China(2017YFA0700104)+1 种基金the National Science Foundation of China(21931007,U21A20286)Jiangsu Funding Program for Excellent Postdoctoral Talent and the 111 Project of China(D17003)。
文摘The low-efficiency CO_(2) uptake capacity and insufficient photogenerated exciton dissociation of current metal halide perovskite(MHP)nanocrystals with end-capping ligands extremely restrict their application in the field of artificial photosynthesis.Herein,we demonstrate that ligand-free CsPbBr_(3) with calliandralike nanostructure(LF-CPB CL)can be synthesized easily through a ligand-free seed-assisted dissolutionrecrystallization growth process,exhibiting significantly enhanced CO_(2) uptake capacity.More specifically,the abundant surface bromine(Br)vacancies in ligand-free MHP materials are demonstrated to be beneficial to photogenerated carrier separation.The electron consumption rate of LF-CPB CL for photocatalytic CO_(2) reduction increases 7 and 20 times over those of traditional ligand-capping CsPbBr_(3)nanocrystal(L-CPB NC)and bulk CsPbBr_(3),respectively.Moreover,the absence of ligand hindrance can facilitate the interfacial electronic coupling between LF-CPB CL and tetra(4-carboxyphenyl)porphyrin iron(Ⅲ)chloride(Fe-TCPP)cocatalyst,bringing forth significantly accelerated interfacial charge separation.The LF-CPB CL/Fe-TCPP exhibits a total electron consumption rate of 145.6μmol g^(-1) h^(-1) for CO_(2)photoreduction coupled with water oxidation which is over 14 times higher than that of L-CPB NC/FeTCPP.
基金Financial support from the National Science Foundation of China (No. 21202049)the Recruitment Program of Global Experts (1000 Talents Plan)+2 种基金Fujian Hundred Talents PlanProgram of Innovative Research Team of Huaqiao UniversityInstrumental Analysis Center of Huaqiao University for analysis support
文摘An efficient copper-catalyzed decarboxylative hydroboration of phenylpropiolic acids with bis（pinacolato）diboron was developed, affording b-vinylboronates as the only products in high yields. Extra hydrogen sources such as methanol are not needed in this catalytic system. This reaction could be performed successfully under ligand- and base-free conditions. It demonstrated that phenylpropiolic acids can be employed as alkyne synthons in the hydroboration reaction and exhibited good reactivity and higher selectivity than terminal alkynes.
基金Project supported by the National Natural Science Foundation of China （No. 30873153）, and the Key Projects of Shanghai in Biomedical （No. 08431902700）.
文摘Symmetrical diynes were synthesized by ligand-free copper-catalyzed homocoupling reaction of 1,1-dibromo-1- alkenes using a DBU/DMSO system at room temperature in good to excellent yields.
基金supported by the Natural Science Foundation of China(91645115 and 21473003)High-level talents funding project of Hebei(CL201601,E2016100015)science technology research and development guidance program project of Baoding City(No.16ZF027)
文摘Carbon-supported copper catalyst was prepared for the first time in one-step with copper nitrate and corn stalk through calcination under different temperatures. Uniformly dispersed nanoparticles were obtained and were identified to be Cu（0） and Cu（Ⅰ） in XRD patterns. Excellent catalytic activity and selectivity were achieved in the N-arylation of pyrazole under ligand and protection gas free conditions. About90.4% of product yield was achieved with only 0.5 mol% of copper catalyst（Cu-C-300）, which was considerably more efficient than previous reports. XPS results suggested that the N-arylation of pyrazole activity was closely related to the surface Cu（Ⅰ） species.
基金the funding support received for this project from the Isfahan University of Technology(1UT),IR Iran (A.R.H.) and Grant GM 33138(A.E.R.)the National Institutes of Health,USA.Further financial support from the Center of Excellency in Chemistry Research(IUT)
文摘The non-toxic and magnetically separable nano-CuFeOcatalyzed synthesis of symmetrical aryl sulfides by the reaction of thiourea with a wide variety of aryl halides,including aryl chlorides has been reported.Excellent yields of products have been obtained under ligand-free conditions and without the use of any expensive catalyst,such as palladium.
基金We are grateful for financial support from the National Natural Science Foundation of China，the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘A simple and efficient protocol for Fe/Cu cocatalyzed oxidative homocoupling reaction of terminal alkynes to symmetrical 1,4-disubstituted-l,3-diynes was presented. The results showed that both CuBr and FeC13 played erucial roles in the reaction. It is noteworthy that this protocol employs mild, efficient, aerobic and ligand free conditions. The alkynes, including aromatic, heteroaromatic and aliphatic alkynes, were transformed into the corresponding 1,3-diynes in good to excellent yields.
文摘The boron trifluoride induced Suzuki-Miyaura cross-coupling of aryltriazenes with arylboronic acids catalyzed by Pd（OAc）2 without added ligands has been achieved for the first time. The reactions performed at room temperature under an argon atmosphere give biaryls in good to excellent yields. It is noteworthy that the reactions were conducted under mild and ligand-free conditions.
文摘The matrix assembly cluster source(MACS)represents a bridge between conventional instruments for cluster beam deposition(CBD)and thelevel of industrial production.The method is based on Ar^+ion sputtering of a pre-condensed Ar-M matrix(where M,is typically a metal such asAg).Each Ar^+ion produces a collision cascade and thus the formation of metal clusters is in the matrix,which are then sputtered out.Here wepresent an experimental and computational investigation of the cluster emission process,specifically its dependence on the Ar^+ion angle of in cidence and the cluster emission angle.We find the in cide nee angle strongly in flue nces the emerging cluster flux,which is assigned to thespatial location of the deposited primary ion energy relative to the cluster into the matrix.We also found an approximately constant anglebetween the incident ion beam and the peak in the emitted cluster distribution,with value between 99°and 109°.
基金supported by the National Basic Research Program of China(Grant No.2015CB932200)the National Natural Science Foundation of China(Grant Nos.21604042,61378081,21574064,and 21674048)+2 种基金Synergetic Innovation Center for Organic Electronics and Information Displays,Jiangsu National Synergetic Innovation Center for Advanced Materials,the Natural Science Foundation of Jiangsu Province of China(No.BK20150843)NUPTSF(Nos.NY215017,NY211003,and NY215080)the Innovation Program for Postgraduates Research of Colleges and Universities of Jiangsu Province(No.CXZZ12-0459).
文摘The synthesis of N-cyclohexyl carbamate-attached fluorene-alt-phenylene copolymer(PFPNCC)and the use of PFPNCC as a“ligand-free”fluorescent chemosensor for Cu(Ⅱ)are described.Addition of Cu(Ⅱ)can efficiently quench the fluorescence of PFPNCC in nucleophilic solvents such as DMF and DMSO,but not in low nucleophilic solvents such as 1,4-dioxane and THF.Ultraviolet-visible spectra of the mixture of the conjugated polymer and Cu(Ⅱ)indicate the presence of a reduced Cu(Ⅰ)ion in the solution.Furthermore,fluorescence recovery of PFPNCC observed at low temperature suggests that the quenching and reducing mechanism is most probably due to a photo-induced electron transfer from excited PFPNCC to Cu(Ⅱ).Our findings provide a novel strategy for highly selective conjugated polymer-based chemosensors for various target analytes,albeit“ligand-free”.
