新的三齿面配位配体 1,4-二氮杂-6-胺(daza)是由乙烷-1,2-二胺和 2,3-二溴-1-丙醇通过七步程序制备的产率为 22%。游离配体的构象已通过 pH 和温度依赖性 1 H NMR 光谱以及 H 3 dazaCl 3 .H 2 O 的单晶 X 射线结构分析阐明。已经为 daza 及其质子化产物 H x daza x + (1 ≤ x ≤ 3) 建立了伯氨基。[M(daza)] 2 + 和[M(daza) 2 ] 2 + 的形成常数已经通过电位和分光光度法在M = Ni II 、Cu II 、Zn II 、Cd II 和Co II 的水溶液中确定测量,与单配合物 ML 相比,双配合物 ML 2 具有非常高的稳定性。这种效应是根据 daza 配体的特定空间要求来讨论的。[Cu(daza)Cl 2 ]、[Ni(daza) 2 ]Cl 2 。3.2H 2 O 和[Zn(daza) 2 ]SO
新的三齿面配位配体 1,4-二氮杂-6-胺(daza)是由乙烷-1,2-二胺和 2,3-二溴-1-丙醇通过七步程序制备的产率为 22%。游离配体的构象已通过 pH 和温度依赖性 1 H NMR 光谱以及 H 3 dazaCl 3 .H 2 O 的单晶 X 射线结构分析阐明。已经为 daza 及其质子化产物 H x daza x + (1 ≤ x ≤ 3) 建立了伯氨基。[M(daza)] 2 + 和[M(daza) 2 ] 2 + 的形成常数已经通过电位和分光光度法在M = Ni II 、Cu II 、Zn II 、Cd II 和Co II 的水溶液中确定测量,与单配合物 ML 相比,双配合物 ML 2 具有非常高的稳定性。这种效应是根据 daza 配体的特定空间要求来讨论的。[Cu(daza)Cl 2 ]、[Ni(daza) 2 ]Cl 2 。3.2H 2 O 和[Zn(daza) 2 ]SO
A novel, efficient, and rapidsynthesis of the 6-amino-perhydro-1,4-diazepine scaffold is reported. It was promoted by microwave or sequential ultrasound/microwave irradiation under solvent-free conditions or in solution. Protected ethylenediamine derivatives and N-Boc-serinol dimesylate underwent rapid cyclization to give 6-aminoperhydro-1,4-diazepine derivatives in excellent yields and with high
Efficient, solventless N-Boc protection of amines carried out at room temperature using sulfamic acid as recyclable catalyst
作者:Dharita J. Upadhyaya、Alessandro Barge、Rachele Stefania、Giancarlo Cravotto
DOI:10.1016/j.tetlet.2007.09.126
日期:2007.11
A simple, rapid, and efficient protocol for the chemoselective N-Boc protection of amines using sulfamic acid as catalyst is described. N-Boc protection of various structurally diverse aliphatic, aromatic, alicyclic, and heterocyclic amines ( 1 degrees, 2 degrees, 3 degrees) was carried out with (Boc)(2)O using sulfamic acid as catalyst (5 mol %) at room temperature under solventless conditions. The advantages of this method are simplicity, shorter reaction times (1-15 min), a cost-effective catalyst, and excellent isolated yields (90-100%); it is also environmentally benign. Moreover, the combined use of ultrasound and sulfamic acid achieves a synergic effect that is especially marked in the N-Boc protection of deactivated (sterically hindered and electron-deficient) amines. The catalyst possesses distinct advantages: ease of handling, cleaner reactions, high activity, and excellent chemoselectivity. (C) 2007 Elsevier Ltd. All rights reserved.