Scandium Trifluoromethanesulfonate (Sc(OTf)₃) as a Novel Reusable Lewis Acid Catalyst in Aldol and Michael Reactions

Synthesis of α-Methylene-γ-lactone Structure by Cyclization of ω-Formylallylsilane in Water

“…Scandium and ytterbium trifluoromethanesulfonate (Sc(OTf) 3 and Yb(OTf) 3 ) are often used as Lewis acid catalysts in aqueous organic reactions. 32,33) However, the expected cyclization reaction did not occur when 1 was treated with these Lewis acids.…”

Synthesis of C‐Glycosides and C‐Disaccharides using Mukaiyama Aldol Reaction in Aqueous Media

“…[8] More recently, Kobayashi and co-workers have considerably improved the reaction [9] in aqueous conditions by showing that water-tolerant Lewis acids, such as ScA C H T U N G T R E N N U N G (OTf) 3 , YA C H T U N G T R E N N U N G (OTf) 3 , lanthanide triflates and salts of Fe(II), Cu(II), Zn(II) and Pb(II) are efficient catalysts and give, in some cases, near quantitative yields of aldol products. [10] The benefits gained by using such aqueous catalytic systems include easy recovery of the active Lewis acid catalyst, [11] decreased cost and increased safety. Moreover, water has unique physical and chemical properties such as a high dielectric constant and a high energy density compared with most organic solvents that allow one to obtain different reactivity and selectivity.…”

The Synthesis of Solvent-Free Glycidic Esters from Diazoesters and Carbonyl Compounds Catalysed by Lanthanide Triflates

“…During the last decade rare earth metal triflates have been found to be unique Lewis acids in that they are watertolerant, reusable catalysts that can effectively promote several important carbon-carbon and carbon-heteroatom bond formation reactions such as aldol condensation, [1] DielsϪAlder and aza DielsϪAlder reactions, [2] FriedelϪ Crafts acylations, [3] Michael additions, [4] allylations of imines [5] and carbonyl compounds, [6] the ring opening of epoxides [7] and aziridines, [8] Mannich reactions, [9] the addition of silyl ketene acetals to nitrones, [10] acetal formation [11] and heterocyclizations. [12,13] Another interesting application is the reaction of diazo derivatives with imines leading to the formation of aziridines.…”