One-Pot Oxidation and Rearrangement of Propargylamines and in Situ Pyrazole Synthesis
摘要:
Reported here are procedures for a one-pot oxidation and rearrangement of propargylamines to synthesize enaminones, with supporting mechanistic studies. Also reported are the extended one-pot syntheses of pyrazoles, including celecoxib and various heterocyclic compounds.
Asymmetric 1,3-dipolarcycloaddition reactions of nitrones with (S)-(-)-4-benzyl-N-methacryloyl-2-oxazolidinone The [3+2]-nitrone-mediated cycloaddition reaction of (S)-(-)-4-benzyl-N-methacryloyl-2-oxazolidinone has been applied to the synthesis of highly substituted isoxazolidines with controlled stereochemistry. The absolute configuration of the major diastereoisorner derived from the reaction between
Regioselective synthesis of some isoxazolines and isoxazolidines bearing caprolactam moiety
作者:Akın Sağirli、Yaşar Dürüst
DOI:10.1080/00397911.2018.1448934
日期:2018.6.18
room temperature and the best protocol have been found for the transformation of nitrones to N-methyl isoxazolidines is silver acetate in refluxing xylene. The structural identification of target compounds was established by IR, nuclear magnetic resonance (NMR), high resolution mass spectrometry (HRMS) spectra, and X-ray diffraction analyses. GRAPHICAL ABSTRACT
摘要异恶唑啉和异恶唑烷系列是通过芳香醛酮和腈氧化物与 N-乙烯基己内酰胺通过区域选择性 1,3-偶极环加成反应获得的,仅以中等产率产生 5-己内酰胺取代的区域异构体。使用不同条件优化环加成反应。用于将腈氧化物转化为异恶唑的一种是室温下的三乙胺,并且已发现将硝酮转化为 N-甲基异恶唑的最佳方案是回流二甲苯中的乙酸银。目标化合物的结构鉴定是通过红外、核磁共振 (NMR)、高分辨率质谱 (HRMS) 光谱和 X 射线衍射分析建立的。图形概要
1, 3-Cycloadditions to Highly Substituted, Strained Double Bonds: Spiro ?-lactams from ?-methylidene-?-lactams by reactions with diphenylnitrilimine, acetonitrile oxide, nitrones, and diazomethane
作者:Arthur Strauss、Hans-Hartwig Otto
DOI:10.1002/hlca.19970800606
日期:1997.9.22
Substituted dihydropyrazole-spiro-β-lactams and isoxazolidine-spiro-β-lactam derivatives are regio- and stereoselectively prepared by 1, 3-cydoadditions between substituted α-methylidene-β-lactams and diazomethane, nitrones, or the in-situ-prepared dipoles ‘diphenylnitrilimine’ and acetonitrileoxide. These reactions represent examples for 1, 3-cycloadditions to the highlysubstituted, strained double
Nitrone and nitrile oxide cycloadditions to bicyclopropylidene. Rearrangement of the isoxazolidine adducts to 3-spirocyclopropane-4-pyridone derivatives
作者:Alberto Brandi、Andrea Goti、Sergei Kozhushkov、Armin de Meijere
DOI:10.1039/c39940002185
日期:——
The two-step nitrone or nitrile oxide cycloaddition–rearrangement thermal process applied to bicyclopropylidene gives 4-pyridone, 7-indolizinone, and 2-quinolizinone derivatives containing a spirocyclopropane linkage α to a carbonyl group.
The reactivity of diphenylvinylphosphinetowardsnitrones is dominated by the dipolarophilic nature of its double bond rather than by the ability of the PIII to act as an oxygen acceptor.