Lanthanide trifluoromethanesulfonates as reusable catalysts. Michael and Diels-Alder reactions

Lanthanide Formamidinates as Improved Catalysts for the Tishchenko Reaction

“…Thus, by using an aluminum alkoxide or K 2 [Fe(CO) 4 ]/crown ether catalysts, very low yields are observed. [21,26,36] For example, only a 3.4 % yield was obtained by using the K 2 [Fe(CO) 4 ]/crown ether catalysts. In contrast, lanthanum formamidinate is much more reactive (Table 2, Entry 3).…”

“…These properties, which can be finetuned by variation of the ionic radius of the lanthanide cation, are the driving force for various catalytic processes. [2] Thus, lanthanide triflates [Ln(OTf) 3 ] turned out to be very active catalysts for aldol, [3] Michael, [4] allylation, [5] Diels-Alder, [6] and glycosylation reactions [7] , as well as for Friedel-Crafts acylations. [8,9] Lanthanide alkoxides [Ln(OR) 3 ] have proven to be useful catalysts for the Meerwein-Ponndorf-Verley reduction [10] and for hydrocyanation, [11] whereas lanthanide shift reagents such as Eu(fod) 3 (fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) can be used as catalysts for Diels-Alder [12] and hetero-Diels-Alder reactions.…”

Diels–Alder Reaction of Cyclopentadiene and Alkyl Acrylates in the Presence of Pyrrolidinium Ionic Liquids with Various Anions

“…A good solubility of the catalysts has been of crucial importance in their applications. The catalysts of these cycloaddition reactions are frequently trifluoromethanesulfonates and chlorides of the rare-earth elements such as: M(OTf) 3 , MCl 3 (M = Sc, La, Ce, Y, OTf ¼ CF 3 SO 3 À ) [10][11][12][13][14][15][16][17][18][19]. The ionic liquids used in this type of reaction include the salts containing imidazolium [20], pyridinium [21], phosphonium [22] cation and bis(trifluoromethylsulfonyl)imide as the anion.…”

Homoleptic Lanthanide Amides as Homogeneous Catalysts for Alkyne Hydroamination and the Tishchenko Reaction

“…On the other hand, lanthanide alkoxides, triflates, and halogenides were used for Lewis acid catalyzed organic reactions. [9] Thus, lanthanide triflates [Ln(OTf) 3 ] are very active catalysts for the aldol, [10] Michael, [11] allylation, [12] Diels ± Alder, [13] and glycosylation reactions [14] as well as for Friedel ± Crafts acylations. [15,16] Lanthanide alkoxides [Ln(OR) 3 ] have proven to be useful catalysts for the Meerwein ± Ponndorf ± Verley reduction [17] and the hydrocyanation, [18] whereas lanthanide shift-reagents, such as [Eu(fod) 3 ] (fod 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato) can be used as a catalyst for the Diels ± Alder [19] and hetero-Diels ± Alder reactions.…”