Intermolecular and Intramolecular α-Amidoalkylation Reactions Using Bismuth Triflate as the Catalyst
摘要:
Bismuth(III) triflate was found to promote the formation of stable cyclic N-acyliminium species in remarkable catalytic amounts (1 mol %). The alpha-amidoalkylation process seems to be effective in intermolecular and intramolecular manners leading to alpha-substituted lactams and heterocyclic systems containing azacycles, respectively. By comparing our results with those obtained with the classical Lewis acids as catalysts, it was evidenced clearly that the use of bismuth(III) triflate had been efficient for nearly all alpha-acetoxy lactams we used, except for N-acyliminium precursors bearing a sulfur atom. Also, the process seems to be easy, general, and clean, having diastereoselectivity comparable to protocols using classical Lewis acids and resulting in the formation of polyheterocyclic systems in good to excellent yields (64-99% in acetonitrile as solvent).
We have developed a catalyst-free synthesis of a series of isoindolinone derivatives via a one-pot, three-component reaction in water using o-formylbenzoic acids, primary amines, and acetophenones as starting materials. An investigation of the influence of the solvent, the substrate molar ratio, the temperature, and the reaction time revealed that the reaction proceeded optimally in water at 70 °C
我们开发了一种以邻甲酰基苯甲酸、伯胺和苯乙酮为起始原料,通过一锅三组分反应在水中无催化剂合成一系列异吲哚酮衍生物的方法。对溶剂、底物摩尔比、温度和反应时间影响的研究表明,反应在 70 °C 的水中进行了 12 小时,得到了多种异吲哚酮衍生物,产率高达 93 %。该方法具有反应条件温和、环境友好、底物范围广泛等优点。