α-Chiral amides are common in pharmaceuticals,agrochemicals,natural products,and peptides,prompting the need for new synthetic methods.Here,we introduce a nickel-catalyzed asymmetric reductive amidation method to syn...α-Chiral amides are common in pharmaceuticals,agrochemicals,natural products,and peptides,prompting the need for new synthetic methods.Here,we introduce a nickel-catalyzed asymmetric reductive amidation method to synthesizeα-chiral amides from benzyl ammonium salts and isocyanates.The key to success is using a chiral 2,2-bipyridine ligand(-)-Ph-SBpy,enabling high yield(up to 95%)and enantiomeric ratio(up to 98:2 er)under mild conditions.Addition of phenol prevents isocyanate polymerization by reversibly forming a carbamate intermediate,enhancing selectivity and efficiency.The synthetic utility is showcased through transformations of the enantioenriched amides,and the mechanism and enantioselectivity are supported by experimental and computational studies.展开更多
A potentially versatile procedure for surface modification of nanometer silica is illustrated by N, N-dicyclohexylcarbodiimide (DCC) mediated amidation of stearic acid.
Polymer-electrolyte-based solid-state Li metal batteries with high-voltage Ni-rich cathodes are promising energy storage technologies owing to their favorable security and high energy densities.However,operating in wi...Polymer-electrolyte-based solid-state Li metal batteries with high-voltage Ni-rich cathodes are promising energy storage technologies owing to their favorable security and high energy densities.However,operating in wide temperature range and at high voltage is a tough challenge for them.Herein,F/N donating fluorinated-amide-based plasticizers regulated polymer electrolyte capable of enabling high-voltage Li||LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)batteries with excellent performance in wide temperature range is developed.F/N donating fluorinated-amide-based plasticizers significantly improve ionic conductivity(1.52 mS/cm at 30℃),enhance oxidation stability(5.0 V vs.Li^(+)/Li)and fabricate robust LiF/Li_(3)N-rich electrode-electrolyte interphases,which significantly improve the interface stability of Li metal anode and NCM811 cathode.The designed polymer electrolyte is nonflammable and has excellent dimensional stability at 200℃.Capitalizing on these advantageous attributes,the Li||NCM811 cells show excellent cycle stability and rate capability from−20℃ to 60℃ at high voltages(∼4.6 V),and under high-loading full cell condition,which display impressive capacity retention of 84.4%after 1000 cycles and ultrahigh capacity of 154.8 mAh/g at 10 C.This work provides a rational design strategy of polymer electrolytes for wide-temperature high-energy solid-state Li metal batteries.展开更多
Poly(ester amide)s(PEAs)represent promising biomaterials because of their well-balanced mechanical properties,biodegradability,and biocompatibility.However,practical applications of PEAs are still limited by challenge...Poly(ester amide)s(PEAs)represent promising biomaterials because of their well-balanced mechanical properties,biodegradability,and biocompatibility.However,practical applications of PEAs are still limited by challenges in functional versatility and environmental adaptability.Here,we present the first synthesis of periodic selenium-incorporated PEAs(Se-PEAs)via a rapid,catalyst-free selenol-yne click polymerization process.By harnessing the versatility of selenium,we achieved precise modulation of material properties.The resulting Se-PEAs demonstrated tunable mechanical behavior,spanning rigid plastics to elastomers,alongside exceptional thermal stability and high optical clarity.Programmable degradation profiles ensure long-term stability in physiological environments while facilitating rapid oxidative degradation at the end of the lifecycle.Surface selenoniumization further conferred robust antibacterial efficacy without compromising mechanical integrity.This multifunctionality positions Se-PEAs as transformative materials for biomedical implants,sustainable packaging,and high-refractiveindex optics.Our work advanced functional polymer design and underscored the potential of selenium chemistry in addressing global challenges in terms of plastic waste and ecological sustainability.展开更多
Rana kunyuensis is a species of brown frog that lives exclusively on Kunyu Mountain,Yantai,China.In the current study,a 279-bp cDNA sequence encoding a novel antimicrobial peptide (AMP),designated as amurin-9KY,was cl...Rana kunyuensis is a species of brown frog that lives exclusively on Kunyu Mountain,Yantai,China.In the current study,a 279-bp cDNA sequence encoding a novel antimicrobial peptide (AMP),designated as amurin-9KY,was cloned from synthesized double-strand skin cDNA of R.kunyuensis.The amurin-9KY precursor was composed of 62 amino acid (aa) residues,whereas the mature peptide was composed of 14 aa and contained two cysteines forming a C-terminal heptapeptide ring (Rana box domain) and an amidated C-terminus.These structural characters represent a novel amphibian AMP family.Although amurin-9KY exhibited high similarity to the already identified amurin-9AM from R.amurensis,little is known about the structures and activities of amurin-9 family AMPs so far.Therefore,amurin-9KY and its three derivatives (amurin-9KY1-3) were designed and synthesized.The structures and activities were examined to evaluate the influence of C-terminal amidation and the heptapeptide ring on the activities and structure of amurin-9KY..Results indicated that C-terminal amidation was essential for antimicrobial activity,whereas both C-terminal amidation and the heptapeptide ring played roles in the low hemolytic activity.Circular dichroism (CD) spectra showed that the four peptides adopted an α-helical conformation in THF/H2O (v/v 1∶1) solution,but a random coil in aqueous solution.Elimination of the C-terminal heptapeptide ring generated two free cysteine residues with unpaired thiol groups,which greatly increased the concentration-dependent anti-oxidant activity.Scanning electron microscopy (SEM) was also performed to determine the possible bactericidal mechanisms.展开更多
The coupling reaction of phenylurea with different functionalized aryl halides in the presence of air stable CuI,N,N-dimethylethylenediamine as a ligand,and K_3PO_4 as a base gives symmetrical and unsymmetrical diaryl...The coupling reaction of phenylurea with different functionalized aryl halides in the presence of air stable CuI,N,N-dimethylethylenediamine as a ligand,and K_3PO_4 as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields.This method is milder than the palladium catalyzed arylation and avoids the use of toxic phosphine ligands.展开更多
Cu2O and Cul were supported on multiwalled carbon nanotubes （MWCNTs） using a wet impregna- tion method, and the resulting materials were fully characterized by powder X-ray diffraction, Fourier transform infrared sp...Cu2O and Cul were supported on multiwalled carbon nanotubes （MWCNTs） using a wet impregna- tion method, and the resulting materials were fully characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, transmission electron microscopy, and temperature-programmed desorption with ammonia analysis. The results of these experiments revealed that Cu2O and CuI were deposited on the MWCNTs in the cubic and γ phases, respectively. These results also showed that the Cu-containing MWCNTs exhibited weak to strong electron-accepting （Lewis acidic） properties. The catalytic activities of these materials were studied for the synthesis of biologically significant N-（pyridin-2-yl）benzamides via the oxidative amidation of aryl aldehydes with 2-aminopyridines. The yields of the products were in the range 50%-95% with 100% selectivity. Notably, the CuI/MWCNT catalyst was much more effective than the Cu2O/MWCNT catalyst with respect to the isolated yield of the product, although the latter of these two catalysts exhibited much better recyclability. A preferential interaction was observed between the polar nature of the acid-activated MWCNTs and the ionic Cu2O compared with covalent CuL The differences in these interactions had a significant impact on the rate of the nucleophilic attack of the amino group of 2-aminopyridine substrate on the carbonyl group of the aryl aldehyde.展开更多
Cp^*Co(Ⅲ)-catalyzed direct C—H amidation of azines has been developed.This co nversion could proceed smoothly in the absence of external oxidants,acids or bases,with excellent regioselectivity and broad functional g...Cp^*Co(Ⅲ)-catalyzed direct C—H amidation of azines has been developed.This co nversion could proceed smoothly in the absence of external oxidants,acids or bases,with excellent regioselectivity and broad functional group tolerance,CO2 was released as the sole byproduct,thus providing an environmentally benign amidation process.The products obtained are important intermediates in organic synthesis.展开更多
基金the National Natural Science Foundation of China(Nos.22150410339,W2432012,22301233 and 22171218)the Ministry of Science and Technology China(No.wgxz2022188)。
文摘α-Chiral amides are common in pharmaceuticals,agrochemicals,natural products,and peptides,prompting the need for new synthetic methods.Here,we introduce a nickel-catalyzed asymmetric reductive amidation method to synthesizeα-chiral amides from benzyl ammonium salts and isocyanates.The key to success is using a chiral 2,2-bipyridine ligand(-)-Ph-SBpy,enabling high yield(up to 95%)and enantiomeric ratio(up to 98:2 er)under mild conditions.Addition of phenol prevents isocyanate polymerization by reversibly forming a carbamate intermediate,enhancing selectivity and efficiency.The synthetic utility is showcased through transformations of the enantioenriched amides,and the mechanism and enantioselectivity are supported by experimental and computational studies.
基金This project was supported by China Postdoctoral Science Foundation and Tsinghua-Zhongda Postdoctoral Science Foundation.
文摘A potentially versatile procedure for surface modification of nanometer silica is illustrated by N, N-dicyclohexylcarbodiimide (DCC) mediated amidation of stearic acid.
基金supported by the Science Foundation of High-Level Talents of Wuyi University(Nos.2019AL017,2021AL002).
文摘Polymer-electrolyte-based solid-state Li metal batteries with high-voltage Ni-rich cathodes are promising energy storage technologies owing to their favorable security and high energy densities.However,operating in wide temperature range and at high voltage is a tough challenge for them.Herein,F/N donating fluorinated-amide-based plasticizers regulated polymer electrolyte capable of enabling high-voltage Li||LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)batteries with excellent performance in wide temperature range is developed.F/N donating fluorinated-amide-based plasticizers significantly improve ionic conductivity(1.52 mS/cm at 30℃),enhance oxidation stability(5.0 V vs.Li^(+)/Li)and fabricate robust LiF/Li_(3)N-rich electrode-electrolyte interphases,which significantly improve the interface stability of Li metal anode and NCM811 cathode.The designed polymer electrolyte is nonflammable and has excellent dimensional stability at 200℃.Capitalizing on these advantageous attributes,the Li||NCM811 cells show excellent cycle stability and rate capability from−20℃ to 60℃ at high voltages(∼4.6 V),and under high-loading full cell condition,which display impressive capacity retention of 84.4%after 1000 cycles and ultrahigh capacity of 154.8 mAh/g at 10 C.This work provides a rational design strategy of polymer electrolytes for wide-temperature high-energy solid-state Li metal batteries.
基金supported by the National Natural Science Foundation of China(21971177)the Natural Science Foundation of the Jiangsu Higher Education Institution of China(22KJA150004)+3 种基金the Suzhou Science and Technology Bureau(SZM2021008)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionsthe Jiangsu Key Laboratory of Advanced Functional Polymers Design and Application,Soochow University,Suzhou Medical and Industrial Cooperation Innovation Project(SZM2022011)the Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis and the Program of Innovative Research Team of Soochow University。
文摘Poly(ester amide)s(PEAs)represent promising biomaterials because of their well-balanced mechanical properties,biodegradability,and biocompatibility.However,practical applications of PEAs are still limited by challenges in functional versatility and environmental adaptability.Here,we present the first synthesis of periodic selenium-incorporated PEAs(Se-PEAs)via a rapid,catalyst-free selenol-yne click polymerization process.By harnessing the versatility of selenium,we achieved precise modulation of material properties.The resulting Se-PEAs demonstrated tunable mechanical behavior,spanning rigid plastics to elastomers,alongside exceptional thermal stability and high optical clarity.Programmable degradation profiles ensure long-term stability in physiological environments while facilitating rapid oxidative degradation at the end of the lifecycle.Surface selenoniumization further conferred robust antibacterial efficacy without compromising mechanical integrity.This multifunctionality positions Se-PEAs as transformative materials for biomedical implants,sustainable packaging,and high-refractiveindex optics.Our work advanced functional polymer design and underscored the potential of selenium chemistry in addressing global challenges in terms of plastic waste and ecological sustainability.
文摘目的探究扩散张量成像(diffusion tensor imaging,DTI)联合酰胺质子转移(amide proton transfer,APT)加权成像对老年早期帕金森病的诊断效能。方法选取2022年6月至2024年6月贵州医科大学附属医院收治的老年早期帕金森病患者127例作为帕金森病组,另外纳入同期在贵州医科大学附属医院体检的健康者113例作为对照组,收集两组一般资料,两组均进行MRI检查及DTI、APT序列扫描,收集两组DTI[平均弥散系数(mean diffusivity,MD)、各向异性分数(fractional anisotropy,FA)]、APT序列参数,采用ROC曲线分析DTI与APT序列联合对老年早期帕金森病的诊断效能。结果帕金森病组和对照组右侧与左侧感兴趣区MD、FA值、非对称磁化转移率(magnetization transfer ratio asymmetry,MTRasym)值比较,差异无统计学意义(P>0.05);帕金森病组黑质、红核、壳核、苍白球DTI-MD值明显高于对照组,差异有统计学意义(P<0.01),两组尾状核头的MTRasym值比较,差异有统计学意义(P<0.05)。ROC曲线分析显示,DTI序列黑质、红核、壳核、苍白球MD值联合APT序列尾状核MTRasym值诊断的曲线下面积为0.905(95%CI:0.865~0.945),明显高于单一参数,差异有统计学意义(P<0.05)。结论DTI、APT成像对老年早期帕金森病具有一定的诊断效能,两者联合能够进一步提高对老年早期帕金森病的诊断效能。
基金supported by grants from the National Natural Science Foundation of China(31772455)Natural Science Foundation of Jiangsu Province(BK20160336and BK20171214)+1 种基金Natural Science Foundation of College in Jiangsu Province(16KJB350004)Suzhou Science and Technology Development Project(SYN201504 and SNG2017045)
文摘Rana kunyuensis is a species of brown frog that lives exclusively on Kunyu Mountain,Yantai,China.In the current study,a 279-bp cDNA sequence encoding a novel antimicrobial peptide (AMP),designated as amurin-9KY,was cloned from synthesized double-strand skin cDNA of R.kunyuensis.The amurin-9KY precursor was composed of 62 amino acid (aa) residues,whereas the mature peptide was composed of 14 aa and contained two cysteines forming a C-terminal heptapeptide ring (Rana box domain) and an amidated C-terminus.These structural characters represent a novel amphibian AMP family.Although amurin-9KY exhibited high similarity to the already identified amurin-9AM from R.amurensis,little is known about the structures and activities of amurin-9 family AMPs so far.Therefore,amurin-9KY and its three derivatives (amurin-9KY1-3) were designed and synthesized.The structures and activities were examined to evaluate the influence of C-terminal amidation and the heptapeptide ring on the activities and structure of amurin-9KY..Results indicated that C-terminal amidation was essential for antimicrobial activity,whereas both C-terminal amidation and the heptapeptide ring played roles in the low hemolytic activity.Circular dichroism (CD) spectra showed that the four peptides adopted an α-helical conformation in THF/H2O (v/v 1∶1) solution,but a random coil in aqueous solution.Elimination of the C-terminal heptapeptide ring generated two free cysteine residues with unpaired thiol groups,which greatly increased the concentration-dependent anti-oxidant activity.Scanning electron microscopy (SEM) was also performed to determine the possible bactericidal mechanisms.
基金Authors are thankful to Head of Department of Chemistry V.G.Vaze College,Mulund(E),Mumbai-81(MS),India and Head of Department of Organic Research Laboratory,S.C.S.College,Omerga-413 606(MS),India for providing the necessary laboratory facilities
文摘The coupling reaction of phenylurea with different functionalized aryl halides in the presence of air stable CuI,N,N-dimethylethylenediamine as a ligand,and K_3PO_4 as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields.This method is milder than the palladium catalyzed arylation and avoids the use of toxic phosphine ligands.
基金DST-SERB for the financial support for this research work(Project number:SERB/F/3690/2013-14)
文摘Cu2O and Cul were supported on multiwalled carbon nanotubes （MWCNTs） using a wet impregna- tion method, and the resulting materials were fully characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, transmission electron microscopy, and temperature-programmed desorption with ammonia analysis. The results of these experiments revealed that Cu2O and CuI were deposited on the MWCNTs in the cubic and γ phases, respectively. These results also showed that the Cu-containing MWCNTs exhibited weak to strong electron-accepting （Lewis acidic） properties. The catalytic activities of these materials were studied for the synthesis of biologically significant N-（pyridin-2-yl）benzamides via the oxidative amidation of aryl aldehydes with 2-aminopyridines. The yields of the products were in the range 50%-95% with 100% selectivity. Notably, the CuI/MWCNT catalyst was much more effective than the Cu2O/MWCNT catalyst with respect to the isolated yield of the product, although the latter of these two catalysts exhibited much better recyclability. A preferential interaction was observed between the polar nature of the acid-activated MWCNTs and the ionic Cu2O compared with covalent CuL The differences in these interactions had a significant impact on the rate of the nucleophilic attack of the amino group of 2-aminopyridine substrate on the carbonyl group of the aryl aldehyde.
基金the Ministry of Science and Technology of China(No.2016YFE0132600)Henan Center for Outstanding Overseas Scientists(No.GZS2020001)。
文摘Cp^*Co(Ⅲ)-catalyzed direct C—H amidation of azines has been developed.This co nversion could proceed smoothly in the absence of external oxidants,acids or bases,with excellent regioselectivity and broad functional group tolerance,CO2 was released as the sole byproduct,thus providing an environmentally benign amidation process.The products obtained are important intermediates in organic synthesis.
