O-Acyl ketoximes has been proven to be versatile building blocks for practical construction of Nheterocycles.In the last few years,diverse catalytic systems have been discovered to enable efficient transformations of ...O-Acyl ketoximes has been proven to be versatile building blocks for practical construction of Nheterocycles.In the last few years,diverse catalytic systems have been discovered to enable efficient transformations of O-acyl ketoximes to a range of nitrogen-heterocycles.Herein,we summarized our recent examples of novel nitrogen-heterocycle formation with new function findings of O-acyl ketoximes through facile aerobic copper catalysis,metal-free N–O bond activation,multi-component assembly,and bis-annulations.From the green chemistry perspective,these works represent efficient methods with high atom economy,high selectivity,and minimized chemical waste.These findings also complement well to the previous mainly copper-based catalytic systems and more importantly enrich the oxime chemistry in organic synthesis.展开更多
An efficient Beckrnann rearrangement of ketoximes was developed using carbon tetrabromide/triphenylphos- phine as an organocatalyst without addition of any acids or metals. The reaction showed good functional group to...An efficient Beckrnann rearrangement of ketoximes was developed using carbon tetrabromide/triphenylphos- phine as an organocatalyst without addition of any acids or metals. The reaction showed good functional group tol- erance and gave various amides in moderate to good yields.展开更多
An iron-catalyzed[4+2]annulation of amidines with α,β-unsaturated ketoxime acetates is described.This strategy employs amidines as CN units and provides a new protocol for the construction of 2,4,6-trisubstituted py...An iron-catalyzed[4+2]annulation of amidines with α,β-unsaturated ketoxime acetates is described.This strategy employs amidines as CN units and provides a new protocol for the construction of 2,4,6-trisubstituted pyrimidines under batch and continuous flow conditions in moderate to good yields,exhibiting good functional group tolerance,scalability and operational simplicity.展开更多
A facile copper-based catalytic system has been developed to enable efficient cyclization of methylketoximes and alkynals.This protocol provides a viable entry to synthetically and pharmaceutically useful 2-acylpyrrol...A facile copper-based catalytic system has been developed to enable efficient cyclization of methylketoximes and alkynals.This protocol provides a viable entry to synthetically and pharmaceutically useful 2-acylpyrroles with a broad range of compatible functionalities.Mechanistically,a key acyl migration is probably involved that leads to the formation of N-acyl pyrroles or otherwise NH pyrroles by further hydrolysis.More importantly,the present reaction system also gives an opportunity to realize three-component pyrrole assembly by simple addition of carboxylic acid.展开更多
The ENDOR spectrum of <sup>14</sup>N-<sup>63</sup>Cu-HAP complex in DMSO/EtOH (5:1) freezing solution at 20 K has been studied using orientational selective method in this paper. The anisotro...The ENDOR spectrum of <sup>14</sup>N-<sup>63</sup>Cu-HAP complex in DMSO/EtOH (5:1) freezing solution at 20 K has been studied using orientational selective method in this paper. The anisotropic superhyperfine coupling tensor and qusdrupole coupling tensor of ligand <sup>14</sup>N nucleus, and the superhyperfine coupling tensor of various <sup>1</sup>H nuclei have been measured precisely. Comparing the superhyperfine coupling tensor of <sup>14</sup>N-nucleus with previous work shows that the analytical method of spectrum is reasonable and the data are reliable in our previous work.展开更多
基金Financial support by the National Natural Science Foundation of China(No.22071211)the Science and Technology Planning Project of Hunan Province(No.2019RS2039)+2 种基金Hunan Provincial Natural Science Foundation of China(No.2020JJ3032)Scientific Research Fund of Education Department of Hunan Province(No.21A0079)Open Research Fund of School of Chemistry and Chemical Engineering of Henan Normal University(No.2022C02)。
文摘O-Acyl ketoximes has been proven to be versatile building blocks for practical construction of Nheterocycles.In the last few years,diverse catalytic systems have been discovered to enable efficient transformations of O-acyl ketoximes to a range of nitrogen-heterocycles.Herein,we summarized our recent examples of novel nitrogen-heterocycle formation with new function findings of O-acyl ketoximes through facile aerobic copper catalysis,metal-free N–O bond activation,multi-component assembly,and bis-annulations.From the green chemistry perspective,these works represent efficient methods with high atom economy,high selectivity,and minimized chemical waste.These findings also complement well to the previous mainly copper-based catalytic systems and more importantly enrich the oxime chemistry in organic synthesis.
文摘An efficient Beckrnann rearrangement of ketoximes was developed using carbon tetrabromide/triphenylphos- phine as an organocatalyst without addition of any acids or metals. The reaction showed good functional group tol- erance and gave various amides in moderate to good yields.
基金the National Natural Science Foundation of China(No.22078150)the National Key R&D Program of China(No.2021YFC2101904)+1 种基金the Jiangsu Province Industrial Prospects and Key Core Technologies-Competitive Projects(No.BE2021083)the Nanjing International Joint R&D Project(No.202002037)for their financial support。
文摘An iron-catalyzed[4+2]annulation of amidines with α,β-unsaturated ketoxime acetates is described.This strategy employs amidines as CN units and provides a new protocol for the construction of 2,4,6-trisubstituted pyrimidines under batch and continuous flow conditions in moderate to good yields,exhibiting good functional group tolerance,scalability and operational simplicity.
基金the National Natural Science Foundation of China(22071211)the Science and Technology Planning Project of Hunan Province(2019RS2039)+2 种基金Hunan Provincial Natural Science Foundation of China(2020JJ3032)the Hunan Provincial Innovative Foundation of Postgraduate(CX20190482,XDCX2019B091)the Collaborative Innovation Center of New Chemical Technologies for Environmental Benignity and Efficient Resource Utilization is gratefully acknowledged.
文摘A facile copper-based catalytic system has been developed to enable efficient cyclization of methylketoximes and alkynals.This protocol provides a viable entry to synthetically and pharmaceutically useful 2-acylpyrroles with a broad range of compatible functionalities.Mechanistically,a key acyl migration is probably involved that leads to the formation of N-acyl pyrroles or otherwise NH pyrroles by further hydrolysis.More importantly,the present reaction system also gives an opportunity to realize three-component pyrrole assembly by simple addition of carboxylic acid.
文摘The ENDOR spectrum of <sup>14</sup>N-<sup>63</sup>Cu-HAP complex in DMSO/EtOH (5:1) freezing solution at 20 K has been studied using orientational selective method in this paper. The anisotropic superhyperfine coupling tensor and qusdrupole coupling tensor of ligand <sup>14</sup>N nucleus, and the superhyperfine coupling tensor of various <sup>1</sup>H nuclei have been measured precisely. Comparing the superhyperfine coupling tensor of <sup>14</sup>N-nucleus with previous work shows that the analytical method of spectrum is reasonable and the data are reliable in our previous work.