Regiocontrolled synthesis of 2,4,6-triarylpyridines from methyl ketones, electron-deficient acetylenes and ammonium acetate
作者:Dmitrii A. Shabalin、Marina Yu. Dvorko、Elena Yu. Schmidt、Boris A. Trofimov
DOI:10.1039/d1ob00193k
日期:——
A novel one-pot two-step approach for the synthesis of 2,4,6-triarylpyridines via t-BuOK/DMSO-promoted C-vinylation of a variety of methyl ketones with electron-deficient acetylenes (alkynones) followed by a cyclization of the in situ generated unsaturated 1,5-dicarbonyl species with ammonium acetate has been developed. This approach possesses competitive advantages such as high regioselectivity, available
Synthesis of Highly Substituted Pyridines through Copper-Catalyzed Condensation of Oximes and α,β-Unsaturated Imines
作者:Wei Wen Tan、Yew Jin Ong、Naohiko Yoshikai
DOI:10.1002/anie.201704378
日期:2017.7.3
A copper-catalyzed condensation reaction of oxime acetates and α,β-unsaturated ketimines to give pyridine derivatives is reported. The reaction features mild conditions, high functional-group compatibility, and high regioselectivity with respect to unsymmetrical oxime acetates, thus allowing the preparation of a wide range of polysubstituted pyridines, many of which are not readily accessible by conventional
An iodine-catalyzed aerobicoxidative formal [4+2] annulation for the construction of polyfunctionalized pyridines in one step has been developed through the green reaction system of catalytic amounts of molecular iodine and amine in combination with oxygen. Various ketones and aldehydes were able to react with different chalcones and β, γ-unsaturated α-ketoesters through this reaction strategy. Synthetically
Addition of cylohexanone to chalcones, obtained from the appropriate acetophenone and benzaldehyde derivatives, under solvent-free conditions gave 1,5-diketones in good yields. Treatment of 1,5-diketones with ammonium acetate in acetic acid afforded directly 2,4-diaryl-5,6,7,8-tetrahydroquinolinederivatives in high yields. The structures of were elucidated by 1H NMR, 13C NMR, IR, and elemental analysis
除环己酮,以查耳酮,从相应的苯乙酮和苯甲醛衍生物得到的,无溶剂的条件下的,得到在良好的产率1,5-二酮类。1,5-二酮的治疗乙酸中的乙酸铵直接提供2,4-二芳基-5,6,7,8-四氢喹啉衍生物高产。的结构通过1 H NMR,13 C NMR,IR和元素分析来阐明。J.杂环化学。(2010)。
Copper-mediated synthesis of <i>N</i>-alkenyl-α,β-unsaturated nitrones and their conversion to tri- and tetrasubstituted pyridines
作者:Dimitra Kontokosta、Daniel S Mueller、Dong-Liang Mo、Wiktoria H Pace、Rachel A Simpson、Laura L Anderson
DOI:10.3762/bjoc.11.226
日期:——
A Chan–Lam reaction has been used to prepare N-alkenyl-α,β-unsaturated nitrones, which undergo a subsequent thermal rearrangement to the corresponding tri- and tetrasubstituted pyridines. The optimization and scope of these transformations is discussed. Initial mechanistic experiments suggest a reaction pathway involving oxygen transfer followed by cyclization.