Compared to well-established 1,5-HAT of N-centered radicals,the synthetic applications of 1,2-HAT process were scarce due to the high barrier and constrained three-membered transition state.Here,we have developed a no...Compared to well-established 1,5-HAT of N-centered radicals,the synthetic applications of 1,2-HAT process were scarce due to the high barrier and constrained three-membered transition state.Here,we have developed a novel C(sp')-H gem-difluoroallylation via a base assisted formal 1,2-HAT of amidyl radicals with the reductive quenching cycle of photocatalyst.This transformation enables the efficient formation ofα-aminoalkyl radicals via 1,2-HAT and showcases good functional group tolerance.Our preliminary mechanistic experiments,along withDensity Functional Theory(DFT)calculations demonstrate thefeasibility of 1,2-HAT of amidyl radicals,especially when assisted by a base.Furthermore,our method also succeeds in the Giese addition of electron-deficient alkenes as well as styrene.展开更多
Photoredox-catalyzed aminoarylation and thioami-nation of unactivated alkenes have been developed,providing novel synthetic routes to access synthe-tically challenging quaternary carbon-centered benzoindolizidinones a...Photoredox-catalyzed aminoarylation and thioami-nation of unactivated alkenes have been developed,providing novel synthetic routes to access synthe-tically challenging quaternary carbon-centered benzoindolizidinones and trifluoromethylthiolated piperidines using readily available starting materials.Notably,these transformations were enabled by merging amidyl radical generation from N-alkyl benzamides with oxidant incorporation.Density functional theory calculations were performed to understand the reaction mechanism and to rationa-lize the regioselectivities.Moreover,the newly deve-loped catalytic aminoarylation provided a convenient synthetic route for natural product tylophorine and its gem-dimethyl analogues with greatly improved drug-like properties such as enhanced solubility and stability.展开更多
基金We thank the National Natural Science Foundation of China(22001233)Zhejiang Provincial Ten Thousand Talent Program(2020R52021)and Zhejiang Normal University for financial support.
文摘Compared to well-established 1,5-HAT of N-centered radicals,the synthetic applications of 1,2-HAT process were scarce due to the high barrier and constrained three-membered transition state.Here,we have developed a novel C(sp')-H gem-difluoroallylation via a base assisted formal 1,2-HAT of amidyl radicals with the reductive quenching cycle of photocatalyst.This transformation enables the efficient formation ofα-aminoalkyl radicals via 1,2-HAT and showcases good functional group tolerance.Our preliminary mechanistic experiments,along withDensity Functional Theory(DFT)calculations demonstrate thefeasibility of 1,2-HAT of amidyl radicals,especially when assisted by a base.Furthermore,our method also succeeds in the Giese addition of electron-deficient alkenes as well as styrene.
基金This study was funded by the National“973”grant from the Ministry of Science and Technology(grant no.2011CB965300)National Natural Science Foundation of China(grant nos.21232001 and 21302106)+1 种基金National Science and Technology Major Project(grant no.2018ZX09711001)Tsinghua University Initiative Scientific Research Program.
文摘Photoredox-catalyzed aminoarylation and thioami-nation of unactivated alkenes have been developed,providing novel synthetic routes to access synthe-tically challenging quaternary carbon-centered benzoindolizidinones and trifluoromethylthiolated piperidines using readily available starting materials.Notably,these transformations were enabled by merging amidyl radical generation from N-alkyl benzamides with oxidant incorporation.Density functional theory calculations were performed to understand the reaction mechanism and to rationa-lize the regioselectivities.Moreover,the newly deve-loped catalytic aminoarylation provided a convenient synthetic route for natural product tylophorine and its gem-dimethyl analogues with greatly improved drug-like properties such as enhanced solubility and stability.
