Transformation of Β-Nitrostyrenes to Carboxylic Acids Using Amberlyst A-26 Supported Hydroperoxide
摘要:
Nitrostyrenes are conveniently converted to the corresponding carboxylic acids in high C yields at room temperature with Amberlyst A-26 supported hydroperoxide which is prepared in situ from 35% hydrogen peroxide and amberlyst A-26 (OH-).
Cyanomethyl anion transfer reagents for diastereoselective Corey–Chaykovsky cyclopropanation reactions
作者:Renè Hommelsheim、Katharina J. Hock、Christian Schumacher、Mohanad A. Hussein、Thanh V. Nguyen、Rene M. Koenigs
DOI:10.1039/c8cc05602a
日期:——
A readily available and bench-stable cyanomethyl sulfonium salt was used in highly diastereoselective Corey–Chaykovsky cyclopropanationreactions of electron-poor olefins. This efficient method provides a rapid route to access densely functionalized cyclopropyl nitriles.
4-Aminothioureaprolinal dithioacetal 4a is a highlyefficientcatalyst for the asymmetric Michaeladdition of ketones and aldehydes to nitroolefins requiring only 3 mol-% catalyst loading. The reactions proceeded smoothly and gave syn selective adducts with excellent yields (up to 98 % yield), diastereoselectivity (up to >99:1 dr), and enantioselectivity (up to 99 % ee) under solvent free conditions
C3-Symmetric Proline-Functionalized Organocatalysts: Enantioselective Michael Addition Reactions
作者:Jarugu Narasimha Moorthy、Satyajit Saha
DOI:10.1002/ejoc.201000569
日期:2010.11
C 3 -Symmetric, tripodal catalyst 4 based on 1,3,5-triethylbenzene, which incorporates the features of a molecular receptor, is shown to catalyze Michaeladditionreactions of carbonyl compounds to β-nitrostyrenes in a high stereoselectivity (up to 99:1 dr and up to 98 % ee).
基于 1,3,5-三乙苯的 C 3 -对称三足催化剂 4 结合了分子受体的特征,显示出以高立体选择性(高达 99: 1 dr 和高达 98 % ee)。
Metal-free three-component synthesis of thioamides from β-nitrostyrenes, amines and elemental sulfur
A metal-free CC bond cleavage reaction of β-nitrostyrenes in the presence of elemental sulfur and secondary amines/amides is described. Elemental sulfur serves as both a raw material and an oxidant for CC bond cleavage, and secondary amines or amides are both feasible nitrogen sources. Besides mild reaction condition and simple work-up procedure, the method provided thioamides with good to excellent
描述了在元素硫和仲胺/酰胺存在下 β-硝基苯乙烯的无金属 C C 键裂解反应。元素硫既是C C 键断裂的原料又是氧化剂,仲胺或酰胺都是可行的氮源。除了温和的反应条件和简单的后处理程序外,该方法还提供了具有良好收率的硫代酰胺。
Novel chiral hydrogen bond donor catalysts based on a 4,5-diaminoxanthene scaffold: application to enantioselective conjugate addition of 1,3-dicarbonyl compounds to nitroalkenes
Novelchiral hydrogen bond donor catalysts based on a 4,5-diamino-9,9′-dimethylxanthene skeleton were designed and synthesized. Among the phenylurea-amide hybrid molecules prepared from various natural/unnatural chiral amino acids, the phenylalanine-derived catalyst, and the proline-derived catalyst were successfully applied to enantioselective conjugate addition of 1,3-dicarbonyl compounds to nitroalkenes