Chiral cyclic amino alcohols with contiguous stereocenters are key building blocks in the synthesis of bioactive molecules and pharmaceuticals.Artificial cascade biocatalysis represents an attractive method for the sy...Chiral cyclic amino alcohols with contiguous stereocenters are key building blocks in the synthesis of bioactive molecules and pharmaceuticals.Artificial cascade biocatalysis represents an attractive method for the synthesis of chiral molecules bearing multiple stereocenters from readily available materials.Here we reported an artificial cascade biocatalysis comprising an epoxide hydrolase,an alcohol dehydrogenase,and a reductive aminase or an amine dehydrogenase.It can be utilized to access all four stereoisomers of 2-aminocyclohexanol with two contiguous stereocenters in high yields(up to 95%)and excellent stereoselectivity(up to 98%de)starting from readily available cyclohexene oxide without isolation of the intermediates.Additionally,the biocatalytic cascade has been successfully extended to the production of structurally diverse 2-(alkylamino)cyclohexanols by replacing ammonia with different organic amines.展开更多
Nor-seco-cucurbit[10]uril(ns-CB[10])is a kinetic product with unique structure.The single bridged methylene in its structure makes the molecular cavity of ns-CB[10]more deformable when compared to ordinary cucurbit[n]...Nor-seco-cucurbit[10]uril(ns-CB[10])is a kinetic product with unique structure.The single bridged methylene in its structure makes the molecular cavity of ns-CB[10]more deformable when compared to ordinary cucurbit[n]uril,reducing its structural stability.Repeated experiments showed that ns-CB[10]gradually cracks in an acidic solution and changes the specificity of cucurbit[5]uril(CB[5])and cucurbit[8]uril(CB[8])under more robust acidic solutions and when heated.A series of experiments were designed to study the transformation behavior of ns-CB[10].It was found that the concentration of ns-CB[10]was correlated with the content distribution of CB[5]and CB[8].This study explores the influencing factors and mechanisms of the transformation of ns-CB[10]to CB[5]and CB[8].The results are of great significance for the application of ns-CB[10],understanding the formation mechanism of cucurbit[n]urils.Furthermore,it provides a new pathway for synthesizing new cucurbit[n]urils.展开更多
Imposing conformational constraints on sp3-rich structures is emerging as an important strategy for structural modification and optimization,which can improve the bioactivity of drugs.Herein,we report a visible-light-...Imposing conformational constraints on sp3-rich structures is emerging as an important strategy for structural modification and optimization,which can improve the bioactivity of drugs.Herein,we report a visible-light-induced photosensitized[2+2]homo-cycloaddition and cross-cycloaddition of cyclopropenes to synthesize tricyclo[3.1.0.0^(2,4)]hexanes as rigidified 3,3,6,6-tetrasubstituted cyclohexanes.Trifluoroacetylsilanes,previously known as trifluoromethyl siloxycarbene precursors,were used as photocatalysts for the first time.The mechanism study supports that the aggregation of cyclopropenes is important to promote their sensitization by trifluoroacetylsilanes through energy transfer.展开更多
文摘Chiral cyclic amino alcohols with contiguous stereocenters are key building blocks in the synthesis of bioactive molecules and pharmaceuticals.Artificial cascade biocatalysis represents an attractive method for the synthesis of chiral molecules bearing multiple stereocenters from readily available materials.Here we reported an artificial cascade biocatalysis comprising an epoxide hydrolase,an alcohol dehydrogenase,and a reductive aminase or an amine dehydrogenase.It can be utilized to access all four stereoisomers of 2-aminocyclohexanol with two contiguous stereocenters in high yields(up to 95%)and excellent stereoselectivity(up to 98%de)starting from readily available cyclohexene oxide without isolation of the intermediates.Additionally,the biocatalytic cascade has been successfully extended to the production of structurally diverse 2-(alkylamino)cyclohexanols by replacing ammonia with different organic amines.
基金financial support of National Natural Science Foundation of China(No.22161010)。
文摘Nor-seco-cucurbit[10]uril(ns-CB[10])is a kinetic product with unique structure.The single bridged methylene in its structure makes the molecular cavity of ns-CB[10]more deformable when compared to ordinary cucurbit[n]uril,reducing its structural stability.Repeated experiments showed that ns-CB[10]gradually cracks in an acidic solution and changes the specificity of cucurbit[5]uril(CB[5])and cucurbit[8]uril(CB[8])under more robust acidic solutions and when heated.A series of experiments were designed to study the transformation behavior of ns-CB[10].It was found that the concentration of ns-CB[10]was correlated with the content distribution of CB[5]and CB[8].This study explores the influencing factors and mechanisms of the transformation of ns-CB[10]to CB[5]and CB[8].The results are of great significance for the application of ns-CB[10],understanding the formation mechanism of cucurbit[n]urils.Furthermore,it provides a new pathway for synthesizing new cucurbit[n]urils.
基金National Key R&D Program of China(No.2022YFA1506100)National Natural Science Foundation of China(Nos.22471201,21901191)+1 种基金Fundamental Research Funds for the Central Universities(No.2042023kf0202)Wuhan University for financial support。
文摘Imposing conformational constraints on sp3-rich structures is emerging as an important strategy for structural modification and optimization,which can improve the bioactivity of drugs.Herein,we report a visible-light-induced photosensitized[2+2]homo-cycloaddition and cross-cycloaddition of cyclopropenes to synthesize tricyclo[3.1.0.0^(2,4)]hexanes as rigidified 3,3,6,6-tetrasubstituted cyclohexanes.Trifluoroacetylsilanes,previously known as trifluoromethyl siloxycarbene precursors,were used as photocatalysts for the first time.The mechanism study supports that the aggregation of cyclopropenes is important to promote their sensitization by trifluoroacetylsilanes through energy transfer.
