An efficient synthesis of 2-amino alcohols by silica gel catalysed opening of epoxide rings by amines

Abstract

Silica gel (60-120 mesh) efficiently catalyses the opening of epoxide rings by amines at rt under solvent-free conditions providing an easy method for the synthesis of 2-amino alcohols. Aromatic and aliphatic amines react with cyclohexene oxide with exclusive formation of the trans-2-aryl/alkylaminocyclohexanols in high yields. A complementary regioselectivity is exhibited by aromatic and aliphatic amines during the reaction with styrene oxide. The epoxide ring of non-styrenoidal unsymmetrical alkene oxide undergoes selective nucleophilic attack at the sterically less hindered carbon by aniline.

Ring-Opening of Oxiranes using Taeniolite-Supported Tris(β-Diketonato)Zirconium

“…Modified Lewis acid complexes based on salen [5,12] and porphyrin [23] ligands have also been reported. Some heterogeneous catalysts such as zeolites [1,18], monmorillonite K-10 [4], silica gel [6], mesoporous aluminosilicate [9,12,14,15,20], CuO/SiO 2 [19], and sulphated yttria-zirconia [25] have been reported as catalysts in the ring-opening of oxiranes. An alternative reaction method using a microwave technique has also been examined [13], even though such a method still experiences difficulties in scale-up processes.…”

Comparative Study of Regioselective Synthesis of β-Aminoalcohols under Solventless Conditions Catalyzed by Sulfated Zirconia and SZ/MCM-41

“…The classical approach for the synthesis of β-aminoalcohols, involving nucleophilic opening of epoxides by amines requires heat treatment and requires an excess of amine. Several catalysts have been utilized in these reactions: montmorillonite [16], Ti(o-i-Pr) 4 [17], SmI 2 , [18] basic metal amides, [19] SmCl 3 [20], metal triflates such as Sn(OTf) 2 , Cu(OTf) 2 , LiOTf and Yb(OTf) 3 [21], ammonium decatungstocerate (IV) [22], RuCl 3 [23], zirconium (IV) chloride [24], cyclodextrins [25] and also CeCl 3 [26], silica-gel [27], alumina [28], ionic liquids [29], water [30] We have successfully used sulfated zirconia for Biginelli condensation reactions, [35] for the Paal Knorr reaction in the synthesis of tetrahydroindolone derivatives [36] and for the acylal protection and deprotection reactions [37]. In this paper we have synthesized, characterized and evaluated sulfated zirconia and SZ/MCM-41 in the oxirane opening with amines to obtain β-aminoalcohols under mild, solventless conditions.…”

Epoxide Hydrolase‐Catalysed Kinetic Resolution of a Spiroepoxide, a Key Building Block of Various 11‐Heterosteroids

“…in anhydrous ethanol (200 mL), 1 mg of silica was added. [26] After 6 days at room temperature, a 96 % yield was observed (GC). After concentration under vacuum and flash chromatography (pentane/diethyl ether, 7/3), the purified amino alcohol was transformed (HCl gas) into its corresponding hydrochloride 3.…”