Bimetallic Pd-Cu/Al_(2)O_(3) was prepared by wetness impregnation method and its catalytic activity on coupling reaction of pyridine to 2,2'-bipyridine was assessed in view of the effects of different molar ratios...Bimetallic Pd-Cu/Al_(2)O_(3) was prepared by wetness impregnation method and its catalytic activity on coupling reaction of pyridine to 2,2'-bipyridine was assessed in view of the effects of different molar ratios of Pd:Cu.It is found that Pd-Cu/Al_(2)O_(3) has the small particle size and good dispersion through the characterization.Compared with Pd/Al_(2)O_(3),Pd-Cu(1:2)/Al_(2)O_(3) is the preferable catalyst under the optimum conditions of 1 MPa N2 pressure,310℃and 16 h.The conversion of pyridine is 35.4%,and the selectivity for 2,2'-Bipyridine is up to 99%,which is much higher activity than Pd/Al_(2)O_(3).The directly coupled synthesis meets the requirements of the atomic economy better.The addition of Cu also reduces the dosage of Pd and lowers the cost.It is worth noting that the recycled Pd-Cu/Al_(2)O_(3) catalyst still shows high activity and stability after three times.展开更多
In the preliminary stage of chemical process design, the choice of chemical reaction route is the key design decision, and the concepts of atom utilization and environmental quotient have become extremely useful tools...In the preliminary stage of chemical process design, the choice of chemical reaction route is the key design decision, and the concepts of atom utilization and environmental quotient have become extremely useful tools. However, the waste quality such as chemical toxicity and other engineering factors have not been taken into account. Therefore, a synthetic route selection index, Iroute, is proposed to determine the suitability of a chemical route in this paper. Iroute considers the effects of 'extended atom economy', material renewability, chemical characteristics and some engineering factors. The extended atom economy concept regards not only the value of the desired product but also the value of byproducts. The methodology by using Iroute to compare different routes is illustrated in case study of cyclohexanone oxime and acrylonitrile manufacture.展开更多
C2 prenylated indoles are widespread in a variety of bioactive natural alkaloids.Therefore,theselective installation of prenyl group at C2 position of NH indoles is of great significance.However,the known protocols ge...C2 prenylated indoles are widespread in a variety of bioactive natural alkaloids.Therefore,theselective installation of prenyl group at C2 position of NH indoles is of great significance.However,the known protocols generally require a multi‐step procedure and stoichiometric promoters.Hereinwe develop a one‐step C2 prenylation of NH indole with cheap tert‐prenyl alcohol enabled by acidcatalysis.Salient features include good regioselectivity,step‐and atom‐economy,broad substratescope,and simple catalytic system.The mechanistic investigations demonstrate that both C2prenylation and C3 prenylation/migration pathways are engaged in the reaction.Notably,this practicalstrategy can be applied to the late‐stage diversification of tryptophan‐based peptides and concisesynthesis of tryprostatin B.展开更多
A new method for the synthesis of ramosetron hydrochloride, the most wildly used 5-HT3 receptor antagonist, was reported. The intermediate 8 was obtained in a high e.e. value via lipase catalyzed hydrolytic kinetic re...A new method for the synthesis of ramosetron hydrochloride, the most wildly used 5-HT3 receptor antagonist, was reported. The intermediate 8 was obtained in a high e.e. value via lipase catalyzed hydrolytic kinetic resolution. Then enantiomerically pure ramosetron hydrochloride was synthesized in two steps with excellent yield （the total yield is 24.6%）. The method provides a new environment friendly and atom economy way to synthesize enantiomerically pure ramosetron.展开更多
Sustainability is the ability to nurture or support a process for a long time without compromising the needs of future generations. Rather, sustainable chemistry is a term that refers to the production of chemical pro...Sustainability is the ability to nurture or support a process for a long time without compromising the needs of future generations. Rather, sustainable chemistry is a term that refers to the production of chemical products and processes that reduce or eliminate the use and production of hazardous substances. Green chemistry creates alternative technologies that are safer for human health and the environment to prevent further damage to human health and the environment, such as reducing the release of hazardous chemicals into the air, leading to reduced lung damage. Although sustainable and environmentally friendly technologies have evolved in other areas of science, their use in redox reactions and industry is still in its early stages. The current review aims to highlight the need for green chemistry as a sustainable chemistry and its principles and its application to produce environmentally friendly industrial products and to reduce or stop the production of harmful intermediates and products during its synthesis process.展开更多
Green chemistry has attracted more attention in the past century.Among the 12 principles of green chemistry,only atom economy and E factor can be expressed quantitatively to depict the impact of a chemical process to ...Green chemistry has attracted more attention in the past century.Among the 12 principles of green chemistry,only atom economy and E factor can be expressed quantitatively to depict the impact of a chemical process to environment.Atom economy was thought better than the traditional yield for evaluating the atom efficiency of raw materials.But it is not enough to reflect the conversion degree of raw material.In this paper,we proposed the concept of real atom economy(RAE)as a metric.RAE could combine the above two factors together to better express the green degree of a process.We further suggested an equation to correlate E factor with RAE.The concept of RAE is proved to be helpful for estimating an environmentally benign process.展开更多
Renewable and biodegradable polylactide (PLA) has excellent mechanical strength but is highly flammable which restricts its practical applications. Many phosphorus/nitrogen (P/N)-based flame retardants are ef- fective...Renewable and biodegradable polylactide (PLA) has excellent mechanical strength but is highly flammable which restricts its practical applications. Many phosphorus/nitrogen (P/N)-based flame retardants are ef- fective in PLA, but their high addition loading usually decreases the mechanical strength of the PLA bulk. For polyphosphoramides, despite high fire-retardant efficiency, their chemical synthesis often generates chemical wastes as byproducts. Herein, we report an atom-economic and highly efficient oligomeric P/N fire retardant (APN) prepared using a mild Michael addition polymerization with no byproducts. Using only 3 wt% APN, the resulting PLA exhibits desired fire retardancy including a UL-94 V-0 rating and a limiting oxygen index of 37.6%. Furthermore, the toughness of the fire-retardant PLA increases by 85% compared to pure PLA, with both tensile strength and thermal stability preserved. This work offers an atom-economic strategy for synthesizing highly efficient P/N fire retardants for use in the creation of fire-resistant PLA with robust mechanical properties.展开更多
Comprehensive Summary,As a typical type of sustainable plastic,polyesters can be recycled or upcycled into value-added chemicals in a variety of methods.However,excess reagents are required for most of the depolymeriz...Comprehensive Summary,As a typical type of sustainable plastic,polyesters can be recycled or upcycled into value-added chemicals in a variety of methods.However,excess reagents are required for most of the depolymerization and upcycling processes,causing the emission of environmental pollutants and the waste of chemical resources.Here we demonstrate a one-pot catalytic process to directly crack polylactic acid into acrylic acid by acid catalyst with the assistance of an ionic liquid,Bu4PBr.Polylactic acid is attacked by the Br–from Bu4PBr and the H+from acid to form oligomers containing Br or acryloyl group,and these oligomers serve as intermediates to produce acrylic acid during their mutual transformation.The acrylic acid is vaporized directly from the reactor and obtained in a collector with a selectivity around 90%when polylactic acid is fully converted.This green process shows great advantages in atom economy compared to the conventional recycling/upcycling methods for polyesters,in addition.展开更多
In recent years,the direct introduction of sulfonyl and sulfenyl groups into unsaturated substrates by using thiosulfonates as unique dual functional reagents has inarguably provided chemists a new platform for the di...In recent years,the direct introduction of sulfonyl and sulfenyl groups into unsaturated substrates by using thiosulfonates as unique dual functional reagents has inarguably provided chemists a new platform for the diverse synthesis of important S-containing derivatives.These 1,n-thiosulfonylation reactions usually feature simple procedures,100%atom economy,and high regioselectivity.This review focuses on the recent advancements in the transformations of thiosulfonates through 1,n-thiosulfonylation involving the formation of two distinct C-S bonds under transition-metal-catalyzed or metal-free conditions,where thiosulfonates act as both a sulfonyl and a sulfenyl component.展开更多
A novel and efficient electro-chemical initiated radical strategy was developed for the preparation of both N-substituted and N-unsubstituted 4-selanylisoquinolin-1(2H)-ones through selenylation of isoquinolin-1(2H)-o...A novel and efficient electro-chemical initiated radical strategy was developed for the preparation of both N-substituted and N-unsubstituted 4-selanylisoquinolin-1(2H)-ones through selenylation of isoquinolin-1(2H)-ones with organodiselenides under chemical oxidant-, additive-free and ambient conditions.展开更多
Copper-catalyzed divergent annulations betweenα-diketones and alkynylα-diketones have been achieved,delivering a series of highly functionalized and biologically important cis-hexahydro-2Hcyclopenta[b]furan(HCPF)and...Copper-catalyzed divergent annulations betweenα-diketones and alkynylα-diketones have been achieved,delivering a series of highly functionalized and biologically important cis-hexahydro-2Hcyclopenta[b]furan(HCPF)and 2-hydroxydihydrofuran-3(2H)-one(HDFO)products with high levels of stereoselectivity under identical conditions.The protocol features the use of earth-abundant copper catalyst,mild conditions,shortening synthetic routes in constructing different molecular frameworks,and reducing the corresponding possible waste production.The substituents of the nucleophilicα-diketones play crucial roles in switching the reaction pathways.展开更多
基金by the Natural Science Foundation of the Higher Education Institutions of Anhui Province(No.KJ2021A0132)the Key Research and Development Program of Anhui Province(No.202104a05020070)the National and Anhui Province College Student Innovation Training Program(Nos.202110364055 and S202010364145)。
文摘Bimetallic Pd-Cu/Al_(2)O_(3) was prepared by wetness impregnation method and its catalytic activity on coupling reaction of pyridine to 2,2'-bipyridine was assessed in view of the effects of different molar ratios of Pd:Cu.It is found that Pd-Cu/Al_(2)O_(3) has the small particle size and good dispersion through the characterization.Compared with Pd/Al_(2)O_(3),Pd-Cu(1:2)/Al_(2)O_(3) is the preferable catalyst under the optimum conditions of 1 MPa N2 pressure,310℃and 16 h.The conversion of pyridine is 35.4%,and the selectivity for 2,2'-Bipyridine is up to 99%,which is much higher activity than Pd/Al_(2)O_(3).The directly coupled synthesis meets the requirements of the atomic economy better.The addition of Cu also reduces the dosage of Pd and lowers the cost.It is worth noting that the recycled Pd-Cu/Al_(2)O_(3) catalyst still shows high activity and stability after three times.
文摘In the preliminary stage of chemical process design, the choice of chemical reaction route is the key design decision, and the concepts of atom utilization and environmental quotient have become extremely useful tools. However, the waste quality such as chemical toxicity and other engineering factors have not been taken into account. Therefore, a synthetic route selection index, Iroute, is proposed to determine the suitability of a chemical route in this paper. Iroute considers the effects of 'extended atom economy', material renewability, chemical characteristics and some engineering factors. The extended atom economy concept regards not only the value of the desired product but also the value of byproducts. The methodology by using Iroute to compare different routes is illustrated in case study of cyclohexanone oxime and acrylonitrile manufacture.
文摘C2 prenylated indoles are widespread in a variety of bioactive natural alkaloids.Therefore,theselective installation of prenyl group at C2 position of NH indoles is of great significance.However,the known protocols generally require a multi‐step procedure and stoichiometric promoters.Hereinwe develop a one‐step C2 prenylation of NH indole with cheap tert‐prenyl alcohol enabled by acidcatalysis.Salient features include good regioselectivity,step‐and atom‐economy,broad substratescope,and simple catalytic system.The mechanistic investigations demonstrate that both C2prenylation and C3 prenylation/migration pathways are engaged in the reaction.Notably,this practicalstrategy can be applied to the late‐stage diversification of tryptophan‐based peptides and concisesynthesis of tryprostatin B.
基金Supported by the National Natural Science Foundation of China(No.20802025)the Jilin Provincial Science & Technol-ogy Sustentation Program, China(Nos.20090585, 20100538)
文摘A new method for the synthesis of ramosetron hydrochloride, the most wildly used 5-HT3 receptor antagonist, was reported. The intermediate 8 was obtained in a high e.e. value via lipase catalyzed hydrolytic kinetic resolution. Then enantiomerically pure ramosetron hydrochloride was synthesized in two steps with excellent yield （the total yield is 24.6%）. The method provides a new environment friendly and atom economy way to synthesize enantiomerically pure ramosetron.
文摘Sustainability is the ability to nurture or support a process for a long time without compromising the needs of future generations. Rather, sustainable chemistry is a term that refers to the production of chemical products and processes that reduce or eliminate the use and production of hazardous substances. Green chemistry creates alternative technologies that are safer for human health and the environment to prevent further damage to human health and the environment, such as reducing the release of hazardous chemicals into the air, leading to reduced lung damage. Although sustainable and environmentally friendly technologies have evolved in other areas of science, their use in redox reactions and industry is still in its early stages. The current review aims to highlight the need for green chemistry as a sustainable chemistry and its principles and its application to produce environmentally friendly industrial products and to reduce or stop the production of harmful intermediates and products during its synthesis process.
文摘Green chemistry has attracted more attention in the past century.Among the 12 principles of green chemistry,only atom economy and E factor can be expressed quantitatively to depict the impact of a chemical process to environment.Atom economy was thought better than the traditional yield for evaluating the atom efficiency of raw materials.But it is not enough to reflect the conversion degree of raw material.In this paper,we proposed the concept of real atom economy(RAE)as a metric.RAE could combine the above two factors together to better express the green degree of a process.We further suggested an equation to correlate E factor with RAE.The concept of RAE is proved to be helpful for estimating an environmentally benign process.
基金the National Natural Science Foundation of China(No.21801097)the Australian Re-search Council(Nos.DP190102992 and FT190100188).
文摘Renewable and biodegradable polylactide (PLA) has excellent mechanical strength but is highly flammable which restricts its practical applications. Many phosphorus/nitrogen (P/N)-based flame retardants are ef- fective in PLA, but their high addition loading usually decreases the mechanical strength of the PLA bulk. For polyphosphoramides, despite high fire-retardant efficiency, their chemical synthesis often generates chemical wastes as byproducts. Herein, we report an atom-economic and highly efficient oligomeric P/N fire retardant (APN) prepared using a mild Michael addition polymerization with no byproducts. Using only 3 wt% APN, the resulting PLA exhibits desired fire retardancy including a UL-94 V-0 rating and a limiting oxygen index of 37.6%. Furthermore, the toughness of the fire-retardant PLA increases by 85% compared to pure PLA, with both tensile strength and thermal stability preserved. This work offers an atom-economic strategy for synthesizing highly efficient P/N fire retardants for use in the creation of fire-resistant PLA with robust mechanical properties.
基金financial support from the National Natural Science Foundation of China(22072002,21932002,21821004)China National Petroleum Corporation-Peking University Strategic Cooperation Project of Fundamental Research.D.M.acknowledges support from the Tencent Foundation through the XPLORER.PRIZE.
文摘Comprehensive Summary,As a typical type of sustainable plastic,polyesters can be recycled or upcycled into value-added chemicals in a variety of methods.However,excess reagents are required for most of the depolymerization and upcycling processes,causing the emission of environmental pollutants and the waste of chemical resources.Here we demonstrate a one-pot catalytic process to directly crack polylactic acid into acrylic acid by acid catalyst with the assistance of an ionic liquid,Bu4PBr.Polylactic acid is attacked by the Br–from Bu4PBr and the H+from acid to form oligomers containing Br or acryloyl group,and these oligomers serve as intermediates to produce acrylic acid during their mutual transformation.The acrylic acid is vaporized directly from the reactor and obtained in a collector with a selectivity around 90%when polylactic acid is fully converted.This green process shows great advantages in atom economy compared to the conventional recycling/upcycling methods for polyesters,in addition.
基金financial support from the Natural Science Foundation of China(No.22001121)Natural Science Foundation of Jiangsu Province(No.BK20180690)+1 种基金Nanjing Tech University(Start-up Grant Nos.39837118 and39837146)Xuzhou Medical University(Start-up Grant No.RC20552038)。
文摘In recent years,the direct introduction of sulfonyl and sulfenyl groups into unsaturated substrates by using thiosulfonates as unique dual functional reagents has inarguably provided chemists a new platform for the diverse synthesis of important S-containing derivatives.These 1,n-thiosulfonylation reactions usually feature simple procedures,100%atom economy,and high regioselectivity.This review focuses on the recent advancements in the transformations of thiosulfonates through 1,n-thiosulfonylation involving the formation of two distinct C-S bonds under transition-metal-catalyzed or metal-free conditions,where thiosulfonates act as both a sulfonyl and a sulfenyl component.
基金financial support from Hunan Provincial Natural Science Foundation of China (Nos. 2019JJ50506 and2019JJ20008)Project supported by the Research Foundation of Education Bureau of Hunan Province (No. 19B501)。
文摘A novel and efficient electro-chemical initiated radical strategy was developed for the preparation of both N-substituted and N-unsubstituted 4-selanylisoquinolin-1(2H)-ones through selenylation of isoquinolin-1(2H)-ones with organodiselenides under chemical oxidant-, additive-free and ambient conditions.
基金the National Natural Science Foundation of China(Nos.22071242 and 21871260)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)+1 种基金Fujian Natural Science Foundation(No.2018J05035)Science and Technology Research Program of the Education Department of Jiangxi Province(No.GJJ1991151)。
文摘Copper-catalyzed divergent annulations betweenα-diketones and alkynylα-diketones have been achieved,delivering a series of highly functionalized and biologically important cis-hexahydro-2Hcyclopenta[b]furan(HCPF)and 2-hydroxydihydrofuran-3(2H)-one(HDFO)products with high levels of stereoselectivity under identical conditions.The protocol features the use of earth-abundant copper catalyst,mild conditions,shortening synthetic routes in constructing different molecular frameworks,and reducing the corresponding possible waste production.The substituents of the nucleophilicα-diketones play crucial roles in switching the reaction pathways.
