Paraquat(PQ)has been used as an herbicide worldwide because of its potent activity against weeds.However,it is highly toxic to humans.The very high fatality of PQ poisoning is due to its inherent toxicity and the lack...Paraquat(PQ)has been used as an herbicide worldwide because of its potent activity against weeds.However,it is highly toxic to humans.The very high fatality of PQ poisoning is due to its inherent toxicity and the lack of any effective treatment.Consequently,developing a non-toxic herbicide with comparable efficacy to PQ will contribute to global food security and help prevent PQ-related fatalities.Herein,we report a new herbicide called dienediamine,which was discovered from how to intervene the redox cycle of PQ,an inherent toxicity nature.Dienediamine,the“reduced"form of PQ with no function as an electron transfer agent,was shown to be non-toxic through comprehensive in vivo and in vitro experiments at molar concentrations equivalent to PQ's absolute lethal dose.Remarkably,dienediamine can undergo conversion to PQ under natural sunlight and ambient air conditions,exhibiting herbicidal activities that are comparable to those of PQ.The conversion of dienediamine to PQ,which is toxic to chloroplasts,is the key mechanism underlying its potent herbicidal activity.Our study discovers that dienediamine is a safe and superior alternative to PQ,possessing significant potential for application in sustainable agriculture globally.展开更多
Surface shortwave radiation(SSR)plays an important role in global energy systems.The new generation of geostationary meteorological satellite Himawari-8,with higher spatiotemporal and spectral resolution,offers a new ...Surface shortwave radiation(SSR)plays an important role in global energy systems.The new generation of geostationary meteorological satellite Himawari-8,with higher spatiotemporal and spectral resolution,offers a new opportunity to retrieve SSR with higher accuracy.In this study,an improved algorithm was applied to estimate instantaneous,hourly,and daily mean SSR using cloud products from the Advanced Himawari Imager(AHI)onboard the Himawari-8 satellite.The validation against Baseline Surface Radiation Network(BSRN)stations showed a root mean square error(RMSE)of 95.8 W m^(-2) for instantaneous SSR,82.4 W m^(-2) for hourly SSR,and 22.8 W m^(-2) for daily SSR and mean bias error(MBE)of-15.8 W m^(-2),-14.1 W m^(-2),and-6.6 W m^(-2).The validation against China Meteorological Administration(CMA)stations showed a RMSE of 99.5 W m^(-2) and MBE of-8.2 W m^(-2) for hourly SSR and RMSE of 27.7 W m^(-2) and MBE of-3.9 W m^(-2) for daily SSR,which are generally better than the Himawari-8 SSR product.Overall,the improved algorithm performed well on the new-generation geostationary satellite,with high accuracy and efficiency,and would contribute to surface process research and photovoltaic engineering applications.展开更多
Chiral phosphorus ligands have played a crucial role for the recent advances in asymmetric catalysis.This review summarizes chiral phosphorus ligands developed from the Laboratory of Professor Xumu Zhang in the latest...Chiral phosphorus ligands have played a crucial role for the recent advances in asymmetric catalysis.This review summarizes chiral phosphorus ligands developed from the Laboratory of Professor Xumu Zhang in the latest 25 years.A number of iconic phosphorus ligands including bisphosphorus ligands with rigid chiral backbone such as BICP,PennPhos,TunePhos,and f-Binaphane,P-chiral bisphosphorus ligands TangPhos,Binapine,and DuanPhos,phosphine-phosphoramidte ligand YanPhos,noncovalent interaction-assisted ferrocenyl phosphorus ligand ZhaoPhos and WudaPhos,and tridentate ferrocenyl phosphorus ligands f-amphox are introduced,and their applications in asymmetric hydrogenation are emphasized.展开更多
A series of structurally novel P-chiral biaryl bisphosphorus ligands L1-L5 （BABIBOPs） are developed, providing high efficiency for the first time in palladium-catalyzed asymmetric hydrogenation of β-aryl and β-alk...A series of structurally novel P-chiral biaryl bisphosphorus ligands L1-L5 （BABIBOPs） are developed, providing high efficiency for the first time in palladium-catalyzed asymmetric hydrogenation of β-aryl and β-alkyl substituted β-keto esters. With the Pd-1.3 （iPr-BABIBOP） catalyst, a series of chiral β-hydroxyl carboxylic esters are formed in excellent enantioselectivities （up to 〉 99% ee） and yields at catalyst loading as low as 0.01 mol%.展开更多
A ligand-free nickel-catalyzed Kumada cross-coupling of aryl bromides and tert-butyl Grignard reagents led to the formation of a series of tert-butyl aryls in moderate to good yields, excellent tBu/iBu ratios, and goo...A ligand-free nickel-catalyzed Kumada cross-coupling of aryl bromides and tert-butyl Grignard reagents led to the formation of a series of tert-butyl aryls in moderate to good yields, excellent tBu/iBu ratios, and good functional group compatibility. A radical coupling process is indicated and a mechanism with a Ni(Ⅰ)-Ni(Ⅲ) catalytic cycle is proposed.展开更多
A palladium-catalyzed 2-alkylation of indoles withα-bromo esters is developed by employing a P,P=O ligand.The method features excellent regioselectivities,mild reaction conditions,and good functional group compatibil...A palladium-catalyzed 2-alkylation of indoles withα-bromo esters is developed by employing a P,P=O ligand.The method features excellent regioselectivities,mild reaction conditions,and good functional group compatibility.The employment of the P,P=O ligand as well as 4 A molecular sieves were crucial for the success of the transformation.Mechanistic studies indicate the reaction proceed through a radical pathway.展开更多
A protecting-group-free enantioselective tandem allylic substitution of o-phenylenediamines and o-aminophenols is realized for the first time with a Pd-WingPhos catalyst,providing expedient access to a series of chira...A protecting-group-free enantioselective tandem allylic substitution of o-phenylenediamines and o-aminophenols is realized for the first time with a Pd-WingPhos catalyst,providing expedient access to a series of chiral vinylsubstituted heterocycles in excellent ee and yields under mild reaction conditions.The protocol is applied successfully to the synthesis of a cholesteryl ester transfer protein(CETP)inhibitor.展开更多
We herein report an effective hydrosilylation of 1,1-disubstituted allenes with a palladium catalyst modified by a monophosphorus ligand,leading to a series ofα-tertiary allylsilanes in high yields and exceptional re...We herein report an effective hydrosilylation of 1,1-disubstituted allenes with a palladium catalyst modified by a monophosphorus ligand,leading to a series ofα-tertiary allylsilanes in high yields and exceptional regiose-lectivities.The employment of BI-DIME is essential for the high reactivities and selectivities.A chiralα-tertiary allylsilane is formed in excellent ee for the first time by employing a chiral monophosphorus ligand.展开更多
基金supported by the National Natural Science Foundation of China(41988101 and 42171360)the National Key Research and Development Program of China(2017YFA0603604)。
基金the National Nature Science Foundation of China(81971822,81270136,82188101,21725205)National Key R&D Program of China(2021YFF0701601,2022YFA1503702).
文摘Paraquat(PQ)has been used as an herbicide worldwide because of its potent activity against weeds.However,it is highly toxic to humans.The very high fatality of PQ poisoning is due to its inherent toxicity and the lack of any effective treatment.Consequently,developing a non-toxic herbicide with comparable efficacy to PQ will contribute to global food security and help prevent PQ-related fatalities.Herein,we report a new herbicide called dienediamine,which was discovered from how to intervene the redox cycle of PQ,an inherent toxicity nature.Dienediamine,the“reduced"form of PQ with no function as an electron transfer agent,was shown to be non-toxic through comprehensive in vivo and in vitro experiments at molar concentrations equivalent to PQ's absolute lethal dose.Remarkably,dienediamine can undergo conversion to PQ under natural sunlight and ambient air conditions,exhibiting herbicidal activities that are comparable to those of PQ.The conversion of dienediamine to PQ,which is toxic to chloroplasts,is the key mechanism underlying its potent herbicidal activity.Our study discovers that dienediamine is a safe and superior alternative to PQ,possessing significant potential for application in sustainable agriculture globally.
基金funded by the National Natural Science Foundation of China(grant number 42171360)the National Key Research and Development Program of China(grant number 2017YFA0603604).
文摘Surface shortwave radiation(SSR)plays an important role in global energy systems.The new generation of geostationary meteorological satellite Himawari-8,with higher spatiotemporal and spectral resolution,offers a new opportunity to retrieve SSR with higher accuracy.In this study,an improved algorithm was applied to estimate instantaneous,hourly,and daily mean SSR using cloud products from the Advanced Himawari Imager(AHI)onboard the Himawari-8 satellite.The validation against Baseline Surface Radiation Network(BSRN)stations showed a root mean square error(RMSE)of 95.8 W m^(-2) for instantaneous SSR,82.4 W m^(-2) for hourly SSR,and 22.8 W m^(-2) for daily SSR and mean bias error(MBE)of-15.8 W m^(-2),-14.1 W m^(-2),and-6.6 W m^(-2).The validation against China Meteorological Administration(CMA)stations showed a RMSE of 99.5 W m^(-2) and MBE of-8.2 W m^(-2) for hourly SSR and RMSE of 27.7 W m^(-2) and MBE of-3.9 W m^(-2) for daily SSR,which are generally better than the Himawari-8 SSR product.Overall,the improved algorithm performed well on the new-generation geostationary satellite,with high accuracy and efficiency,and would contribute to surface process research and photovoltaic engineering applications.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences XDB20000000,CAS(QYZDY-SSW-SLH029)NSFC(21725205,21432007,21572246)+1 种基金STCSM-18520712200K.C.Wong Education Foundation.
文摘Chiral phosphorus ligands have played a crucial role for the recent advances in asymmetric catalysis.This review summarizes chiral phosphorus ligands developed from the Laboratory of Professor Xumu Zhang in the latest 25 years.A number of iconic phosphorus ligands including bisphosphorus ligands with rigid chiral backbone such as BICP,PennPhos,TunePhos,and f-Binaphane,P-chiral bisphosphorus ligands TangPhos,Binapine,and DuanPhos,phosphine-phosphoramidte ligand YanPhos,noncovalent interaction-assisted ferrocenyl phosphorus ligand ZhaoPhos and WudaPhos,and tridentate ferrocenyl phosphorus ligands f-amphox are introduced,and their applications in asymmetric hydrogenation are emphasized.
基金The work is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences （No. XDB20000000）, CAS （QYZDY-SSW-SLH029）, the National Natural Science Foundation of China （Nos. 21432007, 21572246, 21725205） and K C. Wong Education Foundation.
文摘A series of structurally novel P-chiral biaryl bisphosphorus ligands L1-L5 （BABIBOPs） are developed, providing high efficiency for the first time in palladium-catalyzed asymmetric hydrogenation of β-aryl and β-alkyl substituted β-keto esters. With the Pd-1.3 （iPr-BABIBOP） catalyst, a series of chiral β-hydroxyl carboxylic esters are formed in excellent enantioselectivities （up to 〉 99% ee） and yields at catalyst loading as low as 0.01 mol%.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No. XDB20000000)CAS (No. QYZDY-SSW-SLH029)+2 种基金National Natural Science Foundation of China (Nos. 21725205, 21432007, 21572246)STCSM18520712200K.C. Wong Education Foundation
文摘A ligand-free nickel-catalyzed Kumada cross-coupling of aryl bromides and tert-butyl Grignard reagents led to the formation of a series of tert-butyl aryls in moderate to good yields, excellent tBu/iBu ratios, and good functional group compatibility. A radical coupling process is indicated and a mechanism with a Ni(Ⅰ)-Ni(Ⅲ) catalytic cycle is proposed.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)CAS(No.QYZDY-SSW-SLH029)+2 种基金National Natural Science Foundation of China(Nos.21725205,21432007,21572246)STCSM-18520712200K.C.Wong Education Foundation。
文摘A palladium-catalyzed 2-alkylation of indoles withα-bromo esters is developed by employing a P,P=O ligand.The method features excellent regioselectivities,mild reaction conditions,and good functional group compatibility.The employment of the P,P=O ligand as well as 4 A molecular sieves were crucial for the success of the transformation.Mechanistic studies indicate the reaction proceed through a radical pathway.
基金Financial support is provided by the National Natural Science Foundation of China(Nos.82188101,21725205,21432007,21572246,21702223)the Key-Area Research and Development Program of Guangdong Province(No.2020B010188003).
文摘A protecting-group-free enantioselective tandem allylic substitution of o-phenylenediamines and o-aminophenols is realized for the first time with a Pd-WingPhos catalyst,providing expedient access to a series of chiral vinylsubstituted heterocycles in excellent ee and yields under mild reaction conditions.The protocol is applied successfully to the synthesis of a cholesteryl ester transfer protein(CETP)inhibitor.
基金We are grateful for financial support from the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB20000000)Chinese Academy of Sciences(No.QYZDY-SSWSLH029)+1 种基金National Natural Science Foundation of China(Nos.21725205,21432007,21572246 and 21702223)the K.C.Wong Education Foundation.
文摘We herein report an effective hydrosilylation of 1,1-disubstituted allenes with a palladium catalyst modified by a monophosphorus ligand,leading to a series ofα-tertiary allylsilanes in high yields and exceptional regiose-lectivities.The employment of BI-DIME is essential for the high reactivities and selectivities.A chiralα-tertiary allylsilane is formed in excellent ee for the first time by employing a chiral monophosphorus ligand.
