The regioselective synthesis of several aminoepoxides has beenachieved without observing any trace of azetidinols, which are usuallyreported as the exclusive reaction products when aminohalohydrinsare treated with bases. The use of the mild supported base KF-Celitein refluxing acetonitrile is crucial for modulating the excellentregioselectivity observed.
First General Route to Substituted α-Arylamino-α′-chloropropan-2-ones by Oxidation of N-Protected Aminohalohydrins: The Importance of Disrupting Hydrogen Bond Networks
The presence of a network of intra- and intermolecular hydrogen bonds in β-arylamino alcohols, confirmed by both IR spectroscopy and computer modeling, inhibits their oxidation to the corresponding α-amino ketones. A straightforward protocol, including highly regioselective protection (as carbamates) and subsequent oxidation with Dess-Martin periodinane, affords near quantitative yields of the desired N-protected ketones, which upon mild treatment with iodotrimethylsilane leads to a series of differently functionalized α-arylamino-α′-chloro ketones.
通过红外光谱和计算机建模证实,δ-芳香族氨基醇中存在分子内和分子间氢键网络,这抑制了它们氧化成相应的δ-氨基酮。一个简单的方案,包括高区域选择性保护(作为氨基甲酸酯)和随后的 Dess-Martin 高碘烷氧化,可得到接近定量产率的所需 N 保护酮,用碘三甲基硅烷温和处理后,可得到一系列不同官能化的δ-±-芳基氨基-δ′-氯酮。
Synthesis and application of Cu(II) immobilized MCM-41 based solid Lewis acid catalyst for aminolysis reaction under solvent-free condition
作者:Garima Chaudhary、Neha Gupta、Amit Pratap Singh
DOI:10.1016/j.poly.2021.115348
日期:2021.10
An efficient protocol for regioselective ring opening of epoxides using sulfated tungstate: application in synthesis of active pharmaceutical ingredients atenolol, propranolol and ranolazine
作者:Sagar P. Pathare、Krishnacharya G. Akamanchi
DOI:10.1016/j.tetlet.2013.09.065
日期:2013.11
Sulfated tungstate was found to be a new and highly efficient catalyst for opening of epoxide rings by amines to give beta-amino alcohols with high regioselectivity. Various advantages associated with this novel and environmental friendly protocol include solvent-free conditions, short reaction times, high product yields, simple workup procedure and easy recovery and reusability of the catalyst. This protocol has been applied for the synthesis of active pharmaceutical ingredients atenolol, propranolol and ranolazine. (C) 2013 Published by Elsevier Ltd.
Highly Efficient Aminolysis of Epoxides Catalyzed by Reusable Zirconyl Triflate, ZrO(OTf)<sub>2</sub>
Efficient ring opening of epoxides with aromatic amines catalyzed by ZrO(OTf)(2) is reported, and the corresponding beta amino (beta-amino acid) alcohols were obtained in high yields in CH3CN as solvent. The reactions were carried out at room temperature and in the presence of only 1.25 mol% of ZrO(OTf)(2). This catalyst can be reused several times without loss of its activity.