The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis,especially for the multiple stereocenters control of substituted groups on th...The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis,especially for the multiple stereocenters control of substituted groups on the ring owing to the long distance between groups.Thus,stereoselective synthesis of multi-substituted ten-membered rings is attractive.Herein,a rapid assembly of various highly substituted ten-membered nitrogen heterocycles between two 1,3-dipoles through a tandem[3+3]cycloaddition/aza-Claisen rearrangement of N-vinyl-α,β-unsaturated nitrones and aza-oxyallyl or oxyallyl cations are disclosed.Products containing two or multiple stereocenters could be obtained in up to 96%yield with high regioselectivity and diastereoselectivity.Selective N-O bond cleavages of ten-membered nitrogen heterocycles lead to various novel 5,6,6-perifused benzofurans,bicyclo[4.4.0]or bicyclo[5.3.0]skeletons containing three or multiple continuous stereocenters in good yields and high diastereoselectivity.Biological tests show that the obtained ten-membered N-heterocycles and bicyclo[4.4.0]skeletons inhibited nitric oxide generation in LPS-stimulated RAW264.7 cells and might serve as good anti-inflammatory agents.展开更多
基金the National Natural Science Foundation of China(No.22071035)the Natural Science Foundation of Guangxi(Nos.2023GXNSFDA026025,2022GXNSFBA035494)+2 种基金Guangxi Minzu University Scientific Research Funds for Talent Introduction(2022KJQD14)the Student Innovation Training Program(No.202310602014)are greatly appreciated.
文摘The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis,especially for the multiple stereocenters control of substituted groups on the ring owing to the long distance between groups.Thus,stereoselective synthesis of multi-substituted ten-membered rings is attractive.Herein,a rapid assembly of various highly substituted ten-membered nitrogen heterocycles between two 1,3-dipoles through a tandem[3+3]cycloaddition/aza-Claisen rearrangement of N-vinyl-α,β-unsaturated nitrones and aza-oxyallyl or oxyallyl cations are disclosed.Products containing two or multiple stereocenters could be obtained in up to 96%yield with high regioselectivity and diastereoselectivity.Selective N-O bond cleavages of ten-membered nitrogen heterocycles lead to various novel 5,6,6-perifused benzofurans,bicyclo[4.4.0]or bicyclo[5.3.0]skeletons containing three or multiple continuous stereocenters in good yields and high diastereoselectivity.Biological tests show that the obtained ten-membered N-heterocycles and bicyclo[4.4.0]skeletons inhibited nitric oxide generation in LPS-stimulated RAW264.7 cells and might serve as good anti-inflammatory agents.
