Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated ...Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated for the case of selective alkylarene oxidation by molecular oxygen.The proposed catalytic system consists of two widely available components:N-hydroxyphthalimide(NHPI,a homogeneous organocatalyst for free-radical chain reactions)and nanosized TiO_(2)(heterogeneous UV-active photoredox catalyst).The interaction of NHPI with TiO_(2) allows for a shift from UV to visible light photoredox activity and generation of phthalimide-N-oxyl(PINO)radicals that diffuse into the solution where NHPI/PINO-catalyzed free-radical chain reaction can proceed without the additional light input providing a fundamental increase in energy efficiency.The NHPI/TiO_(2) ratio controls the selectivity of oxidation affording preferential formation of hydroperoxide or ketone from alkylarene.展开更多
An innovative visible-light-driven direct hydrogen atom transfer(d-HAT)of Ge–H bond has been developed,wherein the photoexcited 9,10-phenanthraquinone(PCHAT9)serves as an efficient photocatalyst for the generation of...An innovative visible-light-driven direct hydrogen atom transfer(d-HAT)of Ge–H bond has been developed,wherein the photoexcited 9,10-phenanthraquinone(PCHAT9)serves as an efficient photocatalyst for the generation of germanium-centered radicals from germanium hydrides including Ph3GeH,nBu3GeH,and Ph2GeH2.By employing hypervalent iodine reagents as SOMOphiles,this protocol facilitates streamlined germylation through a mechanism involving germyl radical addition followed byβ-cleavage of a carboxyl radical to yield a diverse array of ethynyl-,vinyl-,nitrile-,and phenyl-functionalized germanes.The methodological leap signifies a noteworthy departure from the previous photocatalytic indirect hydrogen atom transfer(i-HAT)relying on combined usage of PCSET with abstractors,which not only advances the methodology for creating germanium radicals in a photocatalytic fashion but also provides access to structurally novel and pharmaceutically promising organogermanium compounds that are difficult to synthesize by routine methods.展开更多
Phosphorus-containing organic compounds are important feedstock for the synthesis of value-added bioactive molecules.Therefore,the development of highly efficient synthetic methods for the construction of phosphorus-e...Phosphorus-containing organic compounds are important feedstock for the synthesis of value-added bioactive molecules.Therefore,the development of highly efficient synthetic methods for the construction of phosphorus-element bonds has drawn huge attention in the past decades[1].Particularly,the formation of P–C bonds from phosphoruscentered radicals has been demonstrated to be one of the most efficient and convenient strategies,which has been widely applied for the synthesis of organic phosphorus compounds in recent years.展开更多
文摘Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated for the case of selective alkylarene oxidation by molecular oxygen.The proposed catalytic system consists of two widely available components:N-hydroxyphthalimide(NHPI,a homogeneous organocatalyst for free-radical chain reactions)and nanosized TiO_(2)(heterogeneous UV-active photoredox catalyst).The interaction of NHPI with TiO_(2) allows for a shift from UV to visible light photoredox activity and generation of phthalimide-N-oxyl(PINO)radicals that diffuse into the solution where NHPI/PINO-catalyzed free-radical chain reaction can proceed without the additional light input providing a fundamental increase in energy efficiency.The NHPI/TiO_(2) ratio controls the selectivity of oxidation affording preferential formation of hydroperoxide or ketone from alkylarene.
基金supported by the National Key R&D Program of China(2021YFB4001100,2021YFB4001101)the National Natural Science Foundation of China(22071222 and 22171249)+4 种基金the Science&Technology Innovation Talents in Universities of Henan Province(23HASTIT003)the Key Research Projects of Universities in Henan Province(23A150054)Natural Science Foundation of Henan Province(232300421363,242300420185)the Key Scientific and Technological Project of Henan Province(232102230140)the Doctor Foundation of Henan University of Engineering(D2022004).
文摘An innovative visible-light-driven direct hydrogen atom transfer(d-HAT)of Ge–H bond has been developed,wherein the photoexcited 9,10-phenanthraquinone(PCHAT9)serves as an efficient photocatalyst for the generation of germanium-centered radicals from germanium hydrides including Ph3GeH,nBu3GeH,and Ph2GeH2.By employing hypervalent iodine reagents as SOMOphiles,this protocol facilitates streamlined germylation through a mechanism involving germyl radical addition followed byβ-cleavage of a carboxyl radical to yield a diverse array of ethynyl-,vinyl-,nitrile-,and phenyl-functionalized germanes.The methodological leap signifies a noteworthy departure from the previous photocatalytic indirect hydrogen atom transfer(i-HAT)relying on combined usage of PCSET with abstractors,which not only advances the methodology for creating germanium radicals in a photocatalytic fashion but also provides access to structurally novel and pharmaceutically promising organogermanium compounds that are difficult to synthesize by routine methods.
文摘Phosphorus-containing organic compounds are important feedstock for the synthesis of value-added bioactive molecules.Therefore,the development of highly efficient synthetic methods for the construction of phosphorus-element bonds has drawn huge attention in the past decades[1].Particularly,the formation of P–C bonds from phosphoruscentered radicals has been demonstrated to be one of the most efficient and convenient strategies,which has been widely applied for the synthesis of organic phosphorus compounds in recent years.
