Development of a Gold-Multifaceted Catalysis Approach to the Synthesis of Highly Substituted Pyrroles: Mechanistic Insights via Huisgen Cycloaddition Studies
作者:Simbarashe Ngwerume、William Lewis、Jason E. Camp
DOI:10.1021/jo302349k
日期:2013.2.1
application of the Huisgen cycloaddition click reaction, which was used to probe the relative stability of substituted O-vinyloximes. The intermediacy of N-alkenylhydroxylamine O-vinyl ethers and imino ketones or imino aldehydes along the reaction pathway were determined by high-temperature 1H, 2H1H}, and 13C1H} NMR experiments. X-ray crystallographic evidence was used to further support the mechanistic hypothesis
通过独立地优化工艺的两个关键步骤,开发了一种直接从肟和炔烃区域选择性合成高度取代的吡咯的金催化新方法。重要的是,阳离子金(I)物种显示出沿反应路径激活多个步骤,因此可作为多面催化剂。最初由金促进的肟氧向活化的炔烃的添加原位提供了O-乙烯基肟。该Ø随后通过金催化的互变异构,[3,3]-σ重排和环脱水过程将-乙烯基肟转化为吡咯。值得注意的是,该方法提供了酯在3/4位的形式的官能团手柄,以便进一步开发。拟议的机理途径得到了Huisgen环加成点击反应的新应用的支持,该反应被用于探测取代的O-乙烯基肟的相对稳定性。的中间性Ñ -alkenylhydroxylamine ø -乙烯基醚和沿反应途径亚氨基酮或亚氨基醛是由高温测定1 H,2 H ^ 1个H},和13 C 11 H NMR实验。X射线晶体学证据被用来进一步支持机理假说。
Sukzessive Ringmethylierung von α-Piperidino-oximen durch wiederholte Zwei-Stufen-Reaktion
作者:Hans Möhrle、Michael Gehlen
DOI:10.1002/ardp.19923250606
日期:——
Durch Dehydrierung von α‐Piperidino‐acetophenonoximen mit Hg(II)‐ED‐TA und konsekutive Grignard‐Reaktion gelingt die stufenweise Ringmethylierung des Piperidin‐Cyclus unter Konfigurationserhalt sowohl bei den E‐als auch den Z‐konfigurierten Isomeren. Die Ringverknüpfung der bicyclischen Oxidationsprodukte läßt sich anhand der 13C‐NMR‐Daten ermitteln.
α-哌啶基-苯乙酮肟与 Hg (II)-ED-TA 和连续格氏反应的脱氢使具有 E 和 Z 构型异构体构型的哌啶循环逐步环甲基化成为可能。双环氧化产物的环键可由 13 C NMR 数据确定。
Stereochemistry of α-aminoacetophenone oximes
作者:H. Moehrle、B. Wehefritz、A. Steigel
DOI:10.1016/s0040-4020(01)86809-5
日期:——
of E- and Z-α-aminoacetophenone oximes depending on the solvent used. Assignment of configuration can be achieved by 13C NMR spectroscopy even if only one isomer is available using a strong solvent dependence of the methylene chemical shift in the case of the Z-isomers. This effect is due to the presence of different conformations in the solvents chloroform and dimethyl sulfoxide. Together with a study
Z-α-卤代苯乙酮肟的氨解反应会导致E-和Z-α-氨基苯乙酮肟的混合物不同,具体取决于所使用的溶剂。即使在Z-异构体的情况下,即使仅一种异构体在对亚甲基化学位移的强烈溶剂依赖性下可用,也可以通过13 C NMR光谱法实现构型分配。该效果是由于在溶剂氯仿和二甲基亚砜中存在不同的构型。结合蒸汽渗透压法的研究,结果为氯仿中Z-α-氨基苯乙酮肟的分子内氢键提供了明确的证据。
SYNTHESIS OF IMIDAZOLE DERIVATIVES FROM α-HALOOXIMES AND AMIDINES BY USE OF IRON CARBONYLS
作者:Saburo Nakanishi、Junji Nantaku、Yoshio Otsuji
DOI:10.1246/cl.1983.341
日期:1983.3.5
The reaction of α-halooximes with amidines in the presence of iron carbonyls gives imidazole derivatives in good yields. This reaction occurs via deoxygenation of 4H-1,2,5-oxadiazines by iron carbonyls.
Insights into the structural patterns of the antileishmanial activity of bi- and tricyclic N-heterocycles
作者:Lizzi Herrera、David E. Stephens、Abigail D'Avila、Kathryn G. George、Hadi Arman、Yu Zhang、George Perry、Ricardo Lleonart、Oleg V. Larionov、Patricia L. Fernández
DOI:10.1039/c6ob01149g
日期:——
various structural patterns in a series of novel bi- and tricyclic N-heterocycles on the activity against Leishmania major and Leishmania panamensis has been studied and compounds that are active in the low micromolar region have been identified. Both quinolines and tetrahydrooxazinoindoles (TOI) proved to have significant antileishmanial activities, while substituted indoles were inactive. We have also