An efficient visible-light induced nickel-catalyzed reductive Heck reaction of alkenes by using mild organic reductant Hantzsch ester(HEH)instead of traditional metal reductants or hydride reagents was developed.The r...An efficient visible-light induced nickel-catalyzed reductive Heck reaction of alkenes by using mild organic reductant Hantzsch ester(HEH)instead of traditional metal reductants or hydride reagents was developed.The reductive hydroarylation of acrylates with aryl halides was successfully achieved without requiring exogenous photoredox catalysts.This reaction is highlighted by the simple and mild conditions,good functional group tolerance,thus providing a complementary approach for alkenes reductive Heck reaction.展开更多
Let f,g and h be three distinct primitive holomorphic cusp forms of even integral weights k_(1),k_(2)and k_(3)for the full modular groupΓ=SL(2,Z),and denote byλ_(f)(n),λ_(g)(n),λ_(h)(n)the corresponding normalized...Let f,g and h be three distinct primitive holomorphic cusp forms of even integral weights k_(1),k_(2)and k_(3)for the full modular groupΓ=SL(2,Z),and denote byλ_(f)(n),λ_(g)(n),λ_(h)(n)the corresponding normalized Fourier coefficients,respectively.In this paper,we investigate the correlations of triple sums associated to these Fourier coefficientsλ_(f)(n),λ_(g)(n),λ_(h)(n)over certain polynomials,and obtain some power-saving asymptotic estimates which beat the trivial bounds.展开更多
SiO2 supported chitosan Schiff-base Palladiam catalyst was prepared and used in the Heck reaction.Effects of the molar ratio of butyl acrylate and iodobenzene,base,the molar ratio of base and ioidobenzene,reaction tem...SiO2 supported chitosan Schiff-base Palladiam catalyst was prepared and used in the Heck reaction.Effects of the molar ratio of butyl acrylate and iodobenzene,base,the molar ratio of base and ioidobenzene,reaction temperature,reaction time and the amount of catalyst used on the yield were investigated by using orthogonal designation method.The order of the effect of the above factors is:base>the amoun t of catalyst>reaction temperature>the molar ratio of base and and iodobenzene>react ion time>the molar ratio of butyl acrylate and iodobenzene.Under the optimal reaction conditions:2 mmol iodobenzene,1.5∶1 molar ratio of butyl acrylate and iodobenzene,1.8∶1 molar ratio of（n-Bu）3N and iodobenzene,0.07g catalyst,4mLODMF,140℃for 4 hours,99.9%yield of buty l cinnamate can be achieved,and the catalyst could be reused for 12 times without the loss of activity.It can also catalyze the coupling reaction of the other substrates in high yields.展开更多
文摘An efficient visible-light induced nickel-catalyzed reductive Heck reaction of alkenes by using mild organic reductant Hantzsch ester(HEH)instead of traditional metal reductants or hydride reagents was developed.The reductive hydroarylation of acrylates with aryl halides was successfully achieved without requiring exogenous photoredox catalysts.This reaction is highlighted by the simple and mild conditions,good functional group tolerance,thus providing a complementary approach for alkenes reductive Heck reaction.
基金Supported in part by NSFC(Nos.12401011,12201214)National Key Research and Development Program of China(No.2021YFA1000700)+3 种基金Shaanxi Fundamental Science Research Project for Mathematics and Physics(No.23JSQ053)Science and Technology Program for Youth New Star of Shaanxi Province(No.2025ZC-KJXX-29)Natural Science Basic Research Program of Shaanxi Province(No.2025JC-YBQN-091)Scientific Research Foundation for Young Talents of WNU(No.2024XJ-QNRC-01)。
文摘Let f,g and h be three distinct primitive holomorphic cusp forms of even integral weights k_(1),k_(2)and k_(3)for the full modular groupΓ=SL(2,Z),and denote byλ_(f)(n),λ_(g)(n),λ_(h)(n)the corresponding normalized Fourier coefficients,respectively.In this paper,we investigate the correlations of triple sums associated to these Fourier coefficientsλ_(f)(n),λ_(g)(n),λ_(h)(n)over certain polynomials,and obtain some power-saving asymptotic estimates which beat the trivial bounds.
文摘SiO2 supported chitosan Schiff-base Palladiam catalyst was prepared and used in the Heck reaction.Effects of the molar ratio of butyl acrylate and iodobenzene,base,the molar ratio of base and ioidobenzene,reaction temperature,reaction time and the amount of catalyst used on the yield were investigated by using orthogonal designation method.The order of the effect of the above factors is:base>the amoun t of catalyst>reaction temperature>the molar ratio of base and and iodobenzene>react ion time>the molar ratio of butyl acrylate and iodobenzene.Under the optimal reaction conditions:2 mmol iodobenzene,1.5∶1 molar ratio of butyl acrylate and iodobenzene,1.8∶1 molar ratio of（n-Bu）3N and iodobenzene,0.07g catalyst,4mLODMF,140℃for 4 hours,99.9%yield of buty l cinnamate can be achieved,and the catalyst could be reused for 12 times without the loss of activity.It can also catalyze the coupling reaction of the other substrates in high yields.
