A Lewis-Acid Catalyzed Synthesis of Substituted Oxindole Derivatives
摘要:
Lewis acid-catalyzed cyclization of various 2-(N-arylcarbamoyl)-methylenemalonates to give nitrogen-containing benzo-annelated heterocycles was investigated in terms of selectivity. Reaction of substrates with various alkyl groups on nitrogen proceeded to give oxindole derivatives. Cyclization reaction of diester-amides of MeO and halooen-substituted anilines in the presence of catalytic Lewis acid (ZnCl2, SnCl4, AlCl3, Zn(OTf)(2), Sc(OTf)(3), etc.) gave oxindoles in high yields. Interesting regioselectivity was observed for meta- halogen substrates. Dimethoxyisoquinoline analogs were also obtained by this reaction using a catalytic Lewis acid.
Amination of Alcohols Catalyzed by Copper-Aluminium Hydrotalcite: A Green Synthesis of Amines
作者:Pravin R. Likhar、Racha Arundhathi、Mannepalli Lakshmi Kantam、Parvathaneni Sai Prathima
DOI:10.1002/ejoc.200900628
日期:2009.11
Copper-aluminiumhydrotalcite (CuAl-HT)/K2CO3 has been employed in the activation of various benzyl alcohols with benzylamines to afford the corresponding amines in good to high yields. Experimentation showed that the reaction takes place through sequential transformations: the oxidation of alcohols into carbonyl compounds, imine formation between amines and carbonyl compounds, and then reduction ofimines
convenient and efficient one-pot reductive amination of diversely substituted aldehydes catalyzed by Fe3O4@TiO2 nanoparticles and NaBH4 as a reductant in ethanol at ambient condition is reported in this work. The structural features of Fe3O4@TiO2 nanoparticles are explored by various tools like FT-IR, XRD, TEM, FE-SEM and EDX techniques. The heterogeneous nature, good catalytic potential and reusability are
本工作报道了在环境条件下,由 Fe 3 O 4 @TiO 2纳米粒子和 NaBH 4作为还原剂在乙醇中催化的不同取代醛的一锅还原胺化,操作方便且高效。Fe 3 O 4 @TiO 2的结构特征纳米粒子可通过多种工具进行探索,例如 FT-IR、XRD、TEM、FE-SEM 和 EDX 技术。多相性质、良好的催化潜力和可重复使用性是催化剂的一些重要属性。该工艺的优点是一锅反应、反应时间短、催化剂用量低、底物适用范围广、收率好、反应条件温和简单。通过1 H-NMR、13 C-NMR 和 HR-MS 谱分析确定了合成的胺衍生物的结构。 图形概要