The construction of chiral C(sp^(3))-rich molecules is of great interest in natural products synthesis and drug discovery.To fulfill the requirement of chiral C(sp^(3))-rich molecules,various approaches have been deve...The construction of chiral C(sp^(3))-rich molecules is of great interest in natural products synthesis and drug discovery.To fulfill the requirement of chiral C(sp^(3))-rich molecules,various approaches have been developed recently.Among these elegant approaches,nickel-catalyzed asymmetric C(sp^(3))-C(sp^(3))cross-coupling has emerged as one of the most appealing approaches,which enables the enantioselective coupling between divergent racemic alkyl electrophiles and racemic alkyl nucleophiles[1,2].展开更多
Atropisomeric C-N compounds belong to an important class of axially chiral compounds.However,whereas the asymmetric synthesis of biaryl atropisomers have been well established,general and efficient strategies to acces...Atropisomeric C-N compounds belong to an important class of axially chiral compounds.However,whereas the asymmetric synthesis of biaryl atropisomers have been well established,general and efficient strategies to access single enantiomers of C-N atropisomers are still rare.Until recently,innovative methods have been developed,providing new opportunities for the highly stereoselective synthesis of this vital class of atropisomers.Herein,we comprehensively summarize the development in this emerging field and give some insights into future advance.Emphasis is placed on the synthetic strategies.展开更多
Let Ψ be the geodesic flow associated with a two-sided invariant metric on a compact Lie group. In this paper, we prove that every ergodic measure μ of Ψ is supported on the unit tangent bundle of a flat torus. As ...Let Ψ be the geodesic flow associated with a two-sided invariant metric on a compact Lie group. In this paper, we prove that every ergodic measure μ of Ψ is supported on the unit tangent bundle of a flat torus. As an application, all Lyapunov exponents of μ are zero hence μ is not hyperbolic. Our underlying manifolds have nonnegative curvature （possibly strictly positive on some sections）, whereas in contrast, all geodesic flows related to negative curvature are Anosov hence every ergodic measure is hyperbolic.展开更多
A strategy for Pd-catalyzed ortho-C–H silylation of biaryl aldehydes enabled by a transient auxiliary is presented. This protocol provides a broad range of ortho-silylated biaryl aldehydes in good yields. The silyl m...A strategy for Pd-catalyzed ortho-C–H silylation of biaryl aldehydes enabled by a transient auxiliary is presented. This protocol provides a broad range of ortho-silylated biaryl aldehydes in good yields. The silyl moiety can be further functionalized under mild conditions, rendering the silylated products useful building blocks. Notably, this protocol also offers an opportunity to establish a platform for expeditious synthesis of structurally diverse axially chiral biaryl aldehydes via sequential atroposelective interannular C–H functionalization/intraanular C–H silylation.展开更多
The merging of C-H and C-C bond cleavage into one single chemical process remains a daunting challenge,especially in an asymmetric manner.Herein,a Pd(Ⅱ)-catalyzed enantioselective tandem C-H/C-C activation for the sy...The merging of C-H and C-C bond cleavage into one single chemical process remains a daunting challenge,especially in an asymmetric manner.Herein,a Pd(Ⅱ)-catalyzed enantioselective tandem C-H/C-C activation for the synthesis of axially chiral biaryls is described.Two types of simple cyclopropanes,such as vinylcyclopropanes and cyclopropanols,were used as efficient and readily available coupling partners.展开更多
基金supported by the National Natural Science Foundation of China(21925109 and U22A20388).
文摘The construction of chiral C(sp^(3))-rich molecules is of great interest in natural products synthesis and drug discovery.To fulfill the requirement of chiral C(sp^(3))-rich molecules,various approaches have been developed recently.Among these elegant approaches,nickel-catalyzed asymmetric C(sp^(3))-C(sp^(3))cross-coupling has emerged as one of the most appealing approaches,which enables the enantioselective coupling between divergent racemic alkyl electrophiles and racemic alkyl nucleophiles[1,2].
基金Financial support from the National Natural Science Foundation of China(Nos.21925109 and 21772170)the Open Research Fund of School Chemistry and Chemical Engineering,Henan Normal University and the Center of Chemistry for Frontier Technologies of Zhejiang University is gratefully acknowledged.
文摘Atropisomeric C-N compounds belong to an important class of axially chiral compounds.However,whereas the asymmetric synthesis of biaryl atropisomers have been well established,general and efficient strategies to access single enantiomers of C-N atropisomers are still rare.Until recently,innovative methods have been developed,providing new opportunities for the highly stereoselective synthesis of this vital class of atropisomers.Herein,we comprehensively summarize the development in this emerging field and give some insights into future advance.Emphasis is placed on the synthetic strategies.
基金supported by National Natural Science Foundation of China (Grant No. 11231001)Education Ministry of China
文摘Let Ψ be the geodesic flow associated with a two-sided invariant metric on a compact Lie group. In this paper, we prove that every ergodic measure μ of Ψ is supported on the unit tangent bundle of a flat torus. As an application, all Lyapunov exponents of μ are zero hence μ is not hyperbolic. Our underlying manifolds have nonnegative curvature （possibly strictly positive on some sections）, whereas in contrast, all geodesic flows related to negative curvature are Anosov hence every ergodic measure is hyperbolic.
基金supported by the National Natural Science Foundation of China (21925109, 21772170)the Outstanding Young Talents of Zhejiang Province High-level Personnel of Special Support (ZJWR0108)+1 种基金the Fundamental Research Funds for the Central Universities (2018XZZX001-02)Zhejiang Provincial Natural Science Foundation (LR17B020001)。
文摘A strategy for Pd-catalyzed ortho-C–H silylation of biaryl aldehydes enabled by a transient auxiliary is presented. This protocol provides a broad range of ortho-silylated biaryl aldehydes in good yields. The silyl moiety can be further functionalized under mild conditions, rendering the silylated products useful building blocks. Notably, this protocol also offers an opportunity to establish a platform for expeditious synthesis of structurally diverse axially chiral biaryl aldehydes via sequential atroposelective interannular C–H functionalization/intraanular C–H silylation.
基金The authors gratefully acknowledge financial support from the NSFC(nos.21772170 and 21925109 for B.-F.S.and no.21901228 for G.L.)Outstanding Young Talents of Zhejiang Province High-level Personnel of Special Support(no.ZJWR0108 for B.-F.S.).
文摘The merging of C-H and C-C bond cleavage into one single chemical process remains a daunting challenge,especially in an asymmetric manner.Herein,a Pd(Ⅱ)-catalyzed enantioselective tandem C-H/C-C activation for the synthesis of axially chiral biaryls is described.Two types of simple cyclopropanes,such as vinylcyclopropanes and cyclopropanols,were used as efficient and readily available coupling partners.
