Lanthanide(III) trifluoromethanesulfonates as extraordinarily effective new catalysts for the aminolysis of 1,2-epoxides

1,2,3,4‐Tetrahydro‐1,5‐naphthyridines and Related Heterocyclic Scaffolds: Exploration of Suitable Chemistry for Library Development.

“…The alkynyl functionality in 7d,e,h can serve as a diversification point for further chemistry such as dipolar cycloadditions. 9 In the 1 H NMR spectra of all the amides, H-8 suffered severe broadening, as did C-8 in the 13 C NMR, due to slow rotation about the amide bond. Heating the samples to 50 °C sharpened the resonances considerably.…”

Synthesis of enantiopure trisubstituted piperidines from a chiral epoxyaziridine and α-amino esters

“…On the other hand, lithium triflate 10 and ytterbium triflate 11 were tested as catalysts in the reaction between epoxyaziridine 2 and L-valine methyl ester 3d. The effect of these catalysts in comparison with the use of lithium perchlorate 12 was performed monitoring the course of the reaction with HPLC and ESI-MS detection.…”

Catalytic, enantioselective synthesis of Boc-protected 1,2-amino alcohols through aminolysis of meso-epoxides with benzophenone imine

“…A solution to this problem was first shown in the work of Crotti who found that lanthanide triflates such as Yb(OTf) 3 are effective catalysts for the aminolysis of 1,2-epoxides, presumably because they are able to exert their exceptional Lewis acidity even in the presence of the amine. 7 Following this precedence Hou et al discovered a Yb(OTf) 3 -R-BINOL-catalyst for the first catalytic, enantioselective aminolysis of cyclohexene oxide with aniline. 8 One major drawback of our procedure for the aminolysis of meso-epoxides, however, stems from the necessity to employ anilines as amine components.…”