The new concepts of the Z-C-X space and excellent cone are introduced. Some problems of random semiclosed 1-set-contractive operator are investigated in the Z-C-X space. At first, an important inequality is proved. Se...The new concepts of the Z-C-X space and excellent cone are introduced. Some problems of random semiclosed 1-set-contractive operator are investigated in the Z-C-X space. At first, an important inequality is proved. Secondly, several new conclusions are proved by means of random fixed point index in the theory of random topological degree. A random solution of a class of random operator equations under conditions of imitating the parallelogram law is obtained, famous Altman's theorem is generalized in partially ordered Z-C-X space. Therefore, some new results are obtained.展开更多
We have summarized the developments and advancements of allyl-(aza)allyl coupling reactions in the past years.Since the first report in 1980,Pd-catalyzed allyl-allyl couplings have not drawn chemists'much attentio...We have summarized the developments and advancements of allyl-(aza)allyl coupling reactions in the past years.Since the first report in 1980,Pd-catalyzed allyl-allyl couplings have not drawn chemists'much attention for almost 20 years.Not until the last two decades,transition-metal-catalyzed allyl-(aza)allyl transformations have been retrieved vital interest and significantly developed in many respects,including metal-catalyst,ligand development,mechanistic understanding,substrate scope,and applications in the preparation of complex functional molecules.This review is organized according to the transition metals used in allyl-allyl coupling reactions including our own work.Besides,transition-metal-free,allyl-azaallyl cross-couplings and applications in the total synthesis of natural products and drugs have also been included.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
文摘The new concepts of the Z-C-X space and excellent cone are introduced. Some problems of random semiclosed 1-set-contractive operator are investigated in the Z-C-X space. At first, an important inequality is proved. Secondly, several new conclusions are proved by means of random fixed point index in the theory of random topological degree. A random solution of a class of random operator equations under conditions of imitating the parallelogram law is obtained, famous Altman's theorem is generalized in partially ordered Z-C-X space. Therefore, some new results are obtained.
基金supported by the National Natural Science Foundation of China(No.22201300)the Fundamental Research Funds for the Central Universities,and the Research Funds of Renmin University of China(No.21XNLG04).
文摘We have summarized the developments and advancements of allyl-(aza)allyl coupling reactions in the past years.Since the first report in 1980,Pd-catalyzed allyl-allyl couplings have not drawn chemists'much attention for almost 20 years.Not until the last two decades,transition-metal-catalyzed allyl-(aza)allyl transformations have been retrieved vital interest and significantly developed in many respects,including metal-catalyst,ligand development,mechanistic understanding,substrate scope,and applications in the preparation of complex functional molecules.This review is organized according to the transition metals used in allyl-allyl coupling reactions including our own work.Besides,transition-metal-free,allyl-azaallyl cross-couplings and applications in the total synthesis of natural products and drugs have also been included.
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.
