The full-parameter geometry optimization of cationic （ S ） - BINAP - Ru （ Ⅱ ） halide complex was performed by DFT method using B3LYP, PW91 and PBE potentials with several basis sets. PW91 with 3-21G / SDD basis s...The full-parameter geometry optimization of cationic （ S ） - BINAP - Ru （ Ⅱ ） halide complex was performed by DFT method using B3LYP, PW91 and PBE potentials with several basis sets. PW91 with 3-21G / SDD basis sets is found to be the most suitable method with consideration of both precision and efficiency. The dihedral angles （ θ ） of the binaphthyl or biphenyl with different phosphorus ligand - Ru （ Ⅱ ） halide complexes were found changing from 59.9 to 79.3 degree, while the natural bite angle （ βn ） of those complexes only changes from 87.4 to 90.3 degree. It is different from the common view of asymmetric organic chemists＇ that θ directly influences βn.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
The history for the development of chiral phos- phorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent ad- vances in the synthesis of the monodentate phosphorus ...The history for the development of chiral phos- phorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent ad- vances in the synthesis of the monodentate phosphorus ligands and their applications in catalytic asymmetric hydrogenation. The examples highlighted in this article clearly demonstrated the importance and advantages of monodentate phosphorus ligands, which had been ignored for 30 a and experienced arenaissance at the very beginning of this millennium, particularly in the area of asymmetric hydrogenation.展开更多
In this paper, a novel and ideal synthetic method of the phosphorus and sulfur hybrid atom ligand is reported. The speciality of this method is that the by-products of some reactions could be used circularly as starti...In this paper, a novel and ideal synthetic method of the phosphorus and sulfur hybrid atom ligand is reported. The speciality of this method is that the by-products of some reactions could be used circularly as starting materials in the synthetic route. Further, we synthesized a series of organopalladium complexes containing these hybrid atom chelate ligands, among them the molecular structures of novelorganopalladium complexes Pd((i-Pr)_2-P(CH_2)_2SEt)Cl_2, Pd(Et_2P(CH_2)_2SEt)Cl_2 and Pd(Ph_2P(CH_2)_2SEt)Cl_2 were determined by using the X-ray single crystal diffraction method. We first used the organotransition metal complexes containing phosphorus and sulfur hybrid atom ligands to activate the σ-C—H bond, and researched the catalytic activity, i.e. the photochemical carbonylation of benzene was catalyzed by these palladium complexes.展开更多
Inherently chiral 6,7-diphenyldibenzo[e,g][1,4]diazocine(DDD)has been synthesized enantioselectively for the first time via chiral phosphoric acid(CPA)-catalyzed cyclocondensation of readily available[1,1′-biphenyl]-...Inherently chiral 6,7-diphenyldibenzo[e,g][1,4]diazocine(DDD)has been synthesized enantioselectively for the first time via chiral phosphoric acid(CPA)-catalyzed cyclocondensation of readily available[1,1′-biphenyl]-2,2′-diamine(1a)and benzil(2a)in 82%yield,with 98%ee under mild reaction conditions.The strategy could also be applied to racemic biaryl diamines through kinetic resolution.The unexpectedly high interconversion energy barriers between the enantiomers(ΔG=39.5 kcal/mol)and the chemical stability rendered DDD an ideal platform for developing new chiral ligands and catalysts.Unique inherently chiralDDD-based phosphoramidites,phosphoric acid,mono-and diphosphine ligands were prepared from optically pure diphenol derivative DDDOL as a common precursor.Preliminary asymmetric reactions catalyzed by Pd or Rh in the presence of newly developed ligands exhibited comparable or even better enantioselectivities than the corresponding BINOLor SPINOL-derived ligands.Density functional theory calculation revealed the origin of the enantioselectivity during the process.展开更多
Theσ-bond activation by main group element has received enormous attention from theoretical and experimental chemists.Here,the reaction of C-X(X=Cl,Br,I)bonds in benzyl and allyl halides with a pincer-type phosphorus...Theσ-bond activation by main group element has received enormous attention from theoretical and experimental chemists.Here,the reaction of C-X(X=Cl,Br,I)bonds in benzyl and allyl halides with a pincer-type phosphorus(Ⅲ)species was reported.A series of structurally robust phosphorus(Ⅴ)compounds were formed via the formal oxidative addition reactions of C-X bonds to the phosphorus(Ⅲ)center.Density functional theory calculations show that the nucleophilic addition process is more favorable than the direct oxidative addition mechanism.Isomerization of bent structures of phosphorus(Ⅲ)compound to poorly nucleophilic compounds to undergo further C-X bond activation can be rationalized by frontier molecule orbital analysis.This study not only provides a deep understanding of the reactivity of phosphorus(Ⅲ)species but also demonstrates a potential of main group elements for the small-molecule activation.展开更多
Based on recent mining rates and the exhaustion of global phosphorus(P)reserves,there is a need to mobilize P already stored in soils,and its recovery from secondary resources such as Ca-and Fe-phosphates is important...Based on recent mining rates and the exhaustion of global phosphorus(P)reserves,there is a need to mobilize P already stored in soils,and its recovery from secondary resources such as Ca-and Fe-phosphates is important.The Ca-phosphate hydroxyapatite forms a good fertilizer source,while vivianite is formed in waterlogged soils and sediments.During sludge treatment,the formation of vivianite has been identified,being mainly Fe-phosphate.Long-term P release from both hydroxyapatite and vivianite was studied using different inorganic(CaCl2 and CaSO4)and organic(citric and humic acid)reagents during batch experiments.Reagents CaCl2 and CaSO4 represent the soil solution,while citric and humic acids as organic constituents affect P availability in the rhizosphere and during the process of humification.Additionally,the flow-through reactor(FTR)technique with an infinite sink was used to study the long-term P release kinetics.The cumulative P release was higher by organic acids than by inorganic compounds.The cumulative P release rates were higher in the FTR with CaCl2 as compared to the batch technique.The infinite sink application caused a continuously high concentration gradient between the solid and liquid phases,leading to higher desorption rates as compared to the batch technique.The predominant amount of the total P released over time was available for a short term.While inorganic anion exchange occurred at easily available binding sites,organic acids affected the more heavily available binding sites,which could be embedded within the mineral structure.The results showed that organic compounds,especially citric acid,play a superior role as compared to the inorganic constituents of the soil solution during the recovery of already stored P from the tertiary phosphates vivianite and hydroxyapatite.展开更多
Asymmetric hydrovinylation of silyl-protected allylic alcohols catalyzed by nickel complexes of chiral spiro phosphoramidite ligands was developed.A series of homoallylic alcohols with a chiral quaternary center were ...Asymmetric hydrovinylation of silyl-protected allylic alcohols catalyzed by nickel complexes of chiral spiro phosphoramidite ligands was developed.A series of homoallylic alcohols with a chiral quaternary center were produced in high yields(up to 97%) and high enantioselectivities(up to 95% ee).The reaction provides an efficient method for preparing bifunctional compounds with a chiral quaternary carbon center.展开更多
The biosorption of phosphorus in the form of orthophosphate（Po） from wastewater using biomass as the sorbent is of potential importance because the Po-loaded biomass could be applied in the agricultural sector as fe...The biosorption of phosphorus in the form of orthophosphate（Po） from wastewater using biomass as the sorbent is of potential importance because the Po-loaded biomass could be applied in the agricultural sector as fertilizer and soil conditioner. However, biomass generally displays a very low affinity for Posorption and therefore biomass surface modification is required. In the present study, the biomass（as model grinded leaves of Phragmites sp. were used）was pretreated with Ca（OH）2to enhance Pobiosorption capacity（qe）. The results indicate that the alkaline pretreatment resulted in a modification of surface functional groups. It was concluded that the main sorption mechanisms were ligand exchange and electrostatic attraction. A series of experiments were conducted to investigate the performance of the pretreated biomass for Pouptake under various conditions. Isotherm and thermodynamic studies were also applied and analyzed. The biosorption process was best described by the pseudo-second order kinetic model and Langmuir isotherm, which gave a qmaxof 12.27 mg P/g at 25°C and p H 7. The Ca（OH）2treated Phragmites biomass applied in this study for Porecovery may present some potential advantages in terms of costs and environmental impact.展开更多
基金the financial support by the National Natural Science Foundation of China(No.20373014).
文摘The full-parameter geometry optimization of cationic （ S ） - BINAP - Ru （ Ⅱ ） halide complex was performed by DFT method using B3LYP, PW91 and PBE potentials with several basis sets. PW91 with 3-21G / SDD basis sets is found to be the most suitable method with consideration of both precision and efficiency. The dihedral angles （ θ ） of the binaphthyl or biphenyl with different phosphorus ligand - Ru （ Ⅱ ） halide complexes were found changing from 59.9 to 79.3 degree, while the natural bite angle （ βn ） of those complexes only changes from 87.4 to 90.3 degree. It is different from the common view of asymmetric organic chemists＇ that θ directly influences βn.
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supported by the National Natural Science Foundation of China(Grant Nos.20225204,20121202,20l320l0 and 20372071)the Chinese Academy of Sciences.the Maior Basic Research Development Program of China(Grant No.G2000077506)the Science and Technology Commission of Shang-hai M unicipality
文摘The history for the development of chiral phos- phorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent ad- vances in the synthesis of the monodentate phosphorus ligands and their applications in catalytic asymmetric hydrogenation. The examples highlighted in this article clearly demonstrated the importance and advantages of monodentate phosphorus ligands, which had been ignored for 30 a and experienced arenaissance at the very beginning of this millennium, particularly in the area of asymmetric hydrogenation.
基金Project supported by the National Natural Science Foundation of China.
文摘In this paper, a novel and ideal synthetic method of the phosphorus and sulfur hybrid atom ligand is reported. The speciality of this method is that the by-products of some reactions could be used circularly as starting materials in the synthetic route. Further, we synthesized a series of organopalladium complexes containing these hybrid atom chelate ligands, among them the molecular structures of novelorganopalladium complexes Pd((i-Pr)_2-P(CH_2)_2SEt)Cl_2, Pd(Et_2P(CH_2)_2SEt)Cl_2 and Pd(Ph_2P(CH_2)_2SEt)Cl_2 were determined by using the X-ray single crystal diffraction method. We first used the organotransition metal complexes containing phosphorus and sulfur hybrid atom ligands to activate the σ-C—H bond, and researched the catalytic activity, i.e. the photochemical carbonylation of benzene was catalyzed by these palladium complexes.
基金the National Natural Science Foundation of China(grant nos.21871268 and 22071250)the Natural Science Foundation of Guangdong Province of China(grant no.2020A1515011428)the“BAGUI Scholar”Program of Guangxi Province of China,and the SKLRD Project(grant no.SKLRD-Z-202014)for financial support.
文摘Inherently chiral 6,7-diphenyldibenzo[e,g][1,4]diazocine(DDD)has been synthesized enantioselectively for the first time via chiral phosphoric acid(CPA)-catalyzed cyclocondensation of readily available[1,1′-biphenyl]-2,2′-diamine(1a)and benzil(2a)in 82%yield,with 98%ee under mild reaction conditions.The strategy could also be applied to racemic biaryl diamines through kinetic resolution.The unexpectedly high interconversion energy barriers between the enantiomers(ΔG=39.5 kcal/mol)and the chemical stability rendered DDD an ideal platform for developing new chiral ligands and catalysts.Unique inherently chiralDDD-based phosphoramidites,phosphoric acid,mono-and diphosphine ligands were prepared from optically pure diphenol derivative DDDOL as a common precursor.Preliminary asymmetric reactions catalyzed by Pd or Rh in the presence of newly developed ligands exhibited comparable or even better enantioselectivities than the corresponding BINOLor SPINOL-derived ligands.Density functional theory calculation revealed the origin of the enantioselectivity during the process.
基金supported by the National Natural Science Foundation of China(Nos.21772088 and 21573179)the Natural Science Foundation of Jiangsu Province(No.BK20170635)the Young Elite Scientist Sponsorship Program of China Association of Science and Technology,the program of Jiangsu SpeciallyAppointed Professor and Shuangchuang Talent Plan of Jiangsu Province。
文摘Theσ-bond activation by main group element has received enormous attention from theoretical and experimental chemists.Here,the reaction of C-X(X=Cl,Br,I)bonds in benzyl and allyl halides with a pincer-type phosphorus(Ⅲ)species was reported.A series of structurally robust phosphorus(Ⅴ)compounds were formed via the formal oxidative addition reactions of C-X bonds to the phosphorus(Ⅲ)center.Density functional theory calculations show that the nucleophilic addition process is more favorable than the direct oxidative addition mechanism.Isomerization of bent structures of phosphorus(Ⅲ)compound to poorly nucleophilic compounds to undergo further C-X bond activation can be rationalized by frontier molecule orbital analysis.This study not only provides a deep understanding of the reactivity of phosphorus(Ⅲ)species but also demonstrates a potential of main group elements for the small-molecule activation.
基金the German Federal Ministry of Education and Research(BMBF)for funding the Bona Res Project Inno Soil Phos(No.031A558)。
文摘Based on recent mining rates and the exhaustion of global phosphorus(P)reserves,there is a need to mobilize P already stored in soils,and its recovery from secondary resources such as Ca-and Fe-phosphates is important.The Ca-phosphate hydroxyapatite forms a good fertilizer source,while vivianite is formed in waterlogged soils and sediments.During sludge treatment,the formation of vivianite has been identified,being mainly Fe-phosphate.Long-term P release from both hydroxyapatite and vivianite was studied using different inorganic(CaCl2 and CaSO4)and organic(citric and humic acid)reagents during batch experiments.Reagents CaCl2 and CaSO4 represent the soil solution,while citric and humic acids as organic constituents affect P availability in the rhizosphere and during the process of humification.Additionally,the flow-through reactor(FTR)technique with an infinite sink was used to study the long-term P release kinetics.The cumulative P release was higher by organic acids than by inorganic compounds.The cumulative P release rates were higher in the FTR with CaCl2 as compared to the batch technique.The infinite sink application caused a continuously high concentration gradient between the solid and liquid phases,leading to higher desorption rates as compared to the batch technique.The predominant amount of the total P released over time was available for a short term.While inorganic anion exchange occurred at easily available binding sites,organic acids affected the more heavily available binding sites,which could be embedded within the mineral structure.The results showed that organic compounds,especially citric acid,play a superior role as compared to the inorganic constituents of the soil solution during the recovery of already stored P from the tertiary phosphates vivianite and hydroxyapatite.
基金the National Natural Science Foundation of Chinathe National Basic Research Program of China (973 Program) (2006CB806106, 2010CB833300)+1 种基金the Ministry of Health (2009ZX09501-017)"111" Project of the Ministry of Education of China (B06005) for financial support
文摘Asymmetric hydrovinylation of silyl-protected allylic alcohols catalyzed by nickel complexes of chiral spiro phosphoramidite ligands was developed.A series of homoallylic alcohols with a chiral quaternary center were produced in high yields(up to 97%) and high enantioselectivities(up to 95% ee).The reaction provides an efficient method for preparing bifunctional compounds with a chiral quaternary carbon center.
文摘The biosorption of phosphorus in the form of orthophosphate（Po） from wastewater using biomass as the sorbent is of potential importance because the Po-loaded biomass could be applied in the agricultural sector as fertilizer and soil conditioner. However, biomass generally displays a very low affinity for Posorption and therefore biomass surface modification is required. In the present study, the biomass（as model grinded leaves of Phragmites sp. were used）was pretreated with Ca（OH）2to enhance Pobiosorption capacity（qe）. The results indicate that the alkaline pretreatment resulted in a modification of surface functional groups. It was concluded that the main sorption mechanisms were ligand exchange and electrostatic attraction. A series of experiments were conducted to investigate the performance of the pretreated biomass for Pouptake under various conditions. Isotherm and thermodynamic studies were also applied and analyzed. The biosorption process was best described by the pseudo-second order kinetic model and Langmuir isotherm, which gave a qmaxof 12.27 mg P/g at 25°C and p H 7. The Ca（OH）2treated Phragmites biomass applied in this study for Porecovery may present some potential advantages in terms of costs and environmental impact.
