The first investigation on catalytic asymmetric [2,3]-sigmatrop-ic rearrangement of sulfur ylides generated from carbenoids and allenic phenyl sulfide was carried out. Up to 55% ee value was obtained.
Organoselenium compounds,due to their high structural diversity,special function,and biological activities,have drawn attention in synthetic chemistry.Herein,a novel example of chiral N,N′-dioxide/cobalt(Ⅱ)complex c...Organoselenium compounds,due to their high structural diversity,special function,and biological activities,have drawn attention in synthetic chemistry.Herein,a novel example of chiral N,N′-dioxide/cobalt(Ⅱ)complex catalyzed asymmetric[2,3]-sigmatropic rearrangement of allylic selenides withα-diazo pyrazoleamides is disclosed,which represents a highly efficient approach to optically active selenides bearing a quaternary C–Se stereocenter.Most of the reactions proceed with 0.5–2 mol%catalyst loading in an inert-free gas atmosphere,and a wealth of chiral selenides are obtained in up to 99% yield and 97%enantiomeric excess(ee).The control experiments demonstrate the high reactivity of allylic selenides,as well as the conspicuous superiority of chiral N,N′-dioxide ligand andα-diazo pyrazoleamide in[2,3]-sigmatropic rearrangement.The mechanism studies reveal that the key to asymmetric rearrangement of allylic selenium ylides is the transfer of chirality from the stable chiral selenium to the carbon of the product.A feasible catalytic cycle is proposed as well.展开更多
The[2,3]-and[1,2]-sigmatropic rearrangement reactions between pyridotriazoles and sulfides catalyzed by rhodium(II)were investigated.The utilization of pyridotriazoles as the carbene precursors in this kind of reactio...The[2,3]-and[1,2]-sigmatropic rearrangement reactions between pyridotriazoles and sulfides catalyzed by rhodium(II)were investigated.The utilization of pyridotriazoles as the carbene precursors in this kind of reaction efficiently constructed the C(sp3)-S and C(sp3)-Se bond with broad substrate scope and great functional group tolerance.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.20225205 and 20172002),State Key Laboratory of Elemento-Organic Chemistry of Nankai University and by Trans-Century Training Programme foundation for the Talents by Ministry of Edu
文摘The first investigation on catalytic asymmetric [2,3]-sigmatrop-ic rearrangement of sulfur ylides generated from carbenoids and allenic phenyl sulfide was carried out. Up to 55% ee value was obtained.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(grant nos.21625205 and 21772127).
文摘Organoselenium compounds,due to their high structural diversity,special function,and biological activities,have drawn attention in synthetic chemistry.Herein,a novel example of chiral N,N′-dioxide/cobalt(Ⅱ)complex catalyzed asymmetric[2,3]-sigmatropic rearrangement of allylic selenides withα-diazo pyrazoleamides is disclosed,which represents a highly efficient approach to optically active selenides bearing a quaternary C–Se stereocenter.Most of the reactions proceed with 0.5–2 mol%catalyst loading in an inert-free gas atmosphere,and a wealth of chiral selenides are obtained in up to 99% yield and 97%enantiomeric excess(ee).The control experiments demonstrate the high reactivity of allylic selenides,as well as the conspicuous superiority of chiral N,N′-dioxide ligand andα-diazo pyrazoleamide in[2,3]-sigmatropic rearrangement.The mechanism studies reveal that the key to asymmetric rearrangement of allylic selenium ylides is the transfer of chirality from the stable chiral selenium to the carbon of the product.A feasible catalytic cycle is proposed as well.
基金Sichuan Science and Technology Program(No.2020YJ0221).
文摘The[2,3]-and[1,2]-sigmatropic rearrangement reactions between pyridotriazoles and sulfides catalyzed by rhodium(II)were investigated.The utilization of pyridotriazoles as the carbene precursors in this kind of reaction efficiently constructed the C(sp3)-S and C(sp3)-Se bond with broad substrate scope and great functional group tolerance.
