Efficient synthesis of β-amino alcohols by regioselective ring-opening of epoxides with anilines catalyzed by sulfated zirconia under solvent-free conditions

A facile and efficient synthesis of β-amino alcohols using 2,2,2-trifluoroethanol as a metal-free and reusable medium

“…Several Lewis acids or Bronsted acids as a useful activator have been reported. That is, high to excellent regioselectivity of aminolysis of epoxides has been observed with Sn(OTf) 2 [16], Cu(OTf) 2 [16], Sm(OTf) 3 [17], Al(OTf) 3 [18], Er(OTf) 3 [19], InCl 3 [20], BiCl 3 [21], SbCl 3 [22], ZnCl 2 [23], InBr 3 [24], CoCl 2 [25], Cu(BF 4 ) 2 [26], Al 2 O 3 [27], ionic liquids [28], silica [29][30], sulfated zirconia [31] and Y(NO 3 ) 3 Á6H 2 O [32]. In general, efficient separation of the amino alcohol product from the Lewis acid catalyst used is often troublesome due to the emulsion formation under basic conditions at the aqueous work-up step.…”

An Efficient Protocol for Aza-Michael Addition Reactions Under Solvent-Free Condition Employing Sulfated Zirconia Catalyst

“…Also in recent times, inorganic solid acid catalyzed organic reactions are gaining much attention due to the proven advantage of heterogeneous catalysts such as simplified product isolation, mild reaction conditions, high selectivity, ease in recovery and reuse of the catalysts, and reduction in the generation of wasteful products [29][30][31]. Sulfated zirconia has been reported to be an excellent catalyst for various organic synthesis and transformation reactions [28,[32][33][34][35][36][37] of industrial significance [26]. Herein, we report the azaMichael addition reaction of amines with a,b-unsaturated carbonyl compounds to produce the corresponding b-amino ketones in high yields (Scheme 1) employing sulfated zirconia (SO 4 2-/ZrO 2 ) catalyst under solvent-free conditions and at ambient temperature.…”

Synthesis of β-amino alcohols catalyzed by poly(vinyl chloride)-supported Schiff base metal complexes

“…The final product 10 was isolated using column chromatography on a small silica column using hexane-ethyl acetate (10:1) as eluent. All products were previously reported [12][13][14][15][16][17][18][19][20][21][22][23][24][25] and were characterized by FTIR and 1 H NMR spectroscopy.…”

“…One of the most important synthetic procedures used to produce b-amino alcohols is the catalyzed ring opening of epoxides by primary amines. This procedure has found widespread application because of the simplicity of the procedure and the availability of a large number of substrates and catalysts that can be used in this reaction [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”