iminyl‐radical formation has been established for the construction of pyridines, quinolines, and phenanthridines from acyl oximes. With fac‐[Ir(ppy)3] as a photoredox catalyst, the acyl oximes were converted by 1 e− reduction into iminyl radical intermediates, which then underwent intramolecular homolytic aromatic substitution (HAS) to give the N‐containing arenes. These reactions proceeded with a broad
已经建立了涉及可见光诱导的亚胺基自由基形成的统一策略,用于从酰基肟中构建吡啶,喹啉和菲啶。用FAC - [的Ir(ppy)3 ]作为催化剂photoredox,酰基肟通过1e中转化-还原成亚氨基自由基中间体,然后行分子内均裂芳族取代(HAS),得到含有N-芳烃其中。这些反应在室温下以宽范围的底物以高收率进行。这种可见光诱导的亚胺基自由基形成策略已成功地应用于五步精简合成苯并[ c ]菲啶生物碱。
Highly stereoselective nickel-catalyzed difluoroalkylation of aryl ketones to tetrasubstituted monofluoroalkenes and quaternary alkyl difluorides
作者:Chao Li、Yi-Xuan Cao、Ruo-Xing Jin、Kang-Jie Bian、Zi-Yang Qin、Quan Lan、Xi-Sheng Wang
DOI:10.1039/c9sc02806d
日期:——
stereo-defined tetrasubstituted monofluoroalkenes or quaternary alkyl difluorides from secondary or tertiary ketones, respectively, has been established. Mechanistic investigations indicated that these C-H fluoroalkylations proceed via a Ni(i)/Ni(iii) catalytic cycle. An obvious fluorine effect was observed in the reaction, and this reaction has demonstrated high stereoselectivity, mild conditions, and broad
Direct synthesis of phenanthrenyl triflates from 1-biphenylyl-2-diazo-2-aryl ketones and triflic anhydride
作者:Yueqiang Liu、Sheng Zhang、Xiujuan Feng、Xiaoqiang Yu、Yoshinori Yamamoto、Ming Bao
DOI:10.1039/d3ob02005c
日期:——
A strategy for directsynthesis of phenanthrenyl triflates from 1-biphenylyl-2-diazo-2-aryl ketones and triflic anhydride is described. The reaction of 1-biphenylyl-2-diazo-2-aryl ketones with triflic anhydride proceeded smoothly in the presence of 2,6-di-tert-butylpyridine under mild conditions to produce phenanthrenyl triflates in high to excellent yields. The phenanthrenyl triflate products were
Metal-Free Nitrogenation of 2-Acetylbiphenyls: Expeditious Synthesis of Phenanthridines
作者:Conghui Tang、Yizhi Yuan、Ning Jiao
DOI:10.1021/acs.orglett.5b00797
日期:2015.5.1
An intermolecular nitrogenation reaction toward the synthesis of phenanthridines has been developed. This metal-free protocol provides a novel nitrogen-incorporation transformation using azides as the nitrogen source. Phenanthridines, which are of great interest in pharmaceutical and medicinal chemistry, are synthesized efficiently in one step. Moreover, the byproducts derived from the Schmidt reaction are inhibited, which further demonstrated the high chemoselectivity of this transformation.
Towards a facile synthesis of triarylethanones: palladium-catalyzed arylation of ketone enolates under homogeneous and heterogeneous conditions
The palladium-catalyzed regioselective alpha-monoarylation of deoxybenzoins and alpha,alpha-diarylation of acetophenones provides general, efficient access to 1,2,2-triarylethanones. After a comprehensive search for suitable experimental conditions to optimize such transformations, both reactions are alternatively conducted by means of either commercially available polymer-anchored catalysts or a very simple homogeneous catalytic system, thus avoiding the use of complex ligands. In addition, the synthesis of deoxybenzoins employing polymer-supported fibrous palladium catalysts is reported for the first time, and the excellent catalyst recycling properties suggest applicability to industrial purposes. (C) 2004 Elsevier Ltd. All rights reserved.