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

Regioselective Ring Opening of Epoxides with Amines Using Silica-bonded S-sulfonic Acid under Solvent-free Conditions

“…Aliphatic amines gave regioisomer B, with the preferential S N 2 attack [32] at the terminal carbon of the epoxides ( Table 3, entries 10-12). This reversal regioselectivity was also observed when aliphatic epoxides such as phenyl glycidyl ether and epoxy propyl methacrylate were employed in this reaction ( Table 3, entries [13][14][15][16][17][18][19][20][21]. Steric factor seems to be responsible for the observed regioselectivity.…”

“…There are some limitations to this classical approach such as the requirement of elevated reaction temperatures in the case of less reactive amines, lower reactivity for the sterically crowded amines/epoxides and poor regioselectivity of the epoxide ring opening. To overcome these problems, several activators and promoters have been tried and reported in the literature, including metal salts [5][6][7], metal amides [8,9], metal alkoxides [10,11], metal triflates [12][13][14], alumina [15], microwave assisted montmorillonite clay [16], ionic liquids [17], heteropolyacids [18], amberlist-15 [19], thiourea [20], trifluoroethanol [21], silica [22], zeolites [23], organobismuth triflate complex [24], sulphated zirconia and SZ/MCM-41 [25]. However, these methods suffer from one or more disadvantages such as long reaction times [26], elevated temperatures [4,27], high pressure [22a, 28], moderate yields [18], use of air and moisture sensitive catalysts, requirement of stoichiometric amounts of catalyst, and problems in the recovery of the catalysts [26].…”

Fluorinated alcohols: A magic medium for the synthesis of heterocyclic compounds

“…M a n u s c r i p t 5 protection and deprotection of amine groups, [39,40], cyclopropanation of alkenes [41], and oxirane ring-opening without any catalyst [42,43].…”

Evolution of Epoxides to Synthesize b-amino Alcohols

“…Khaksar and co-workers 61 found a facile and efficient synthesis using 2,2,2-trifluoroethanol (TFE) as a metal-free and reusable medium (Fig. 19).…”