Highly regioselective intramolecular aminolysis of 3,4-epoxy amines has been achieved. Key features of this reaction are (1) chemoselective activation of epoxides in the presence of unprotected aliphatic amines in the same molecules by a La(OTf) catalyst and (2) excellent regioselectivity for anti-Baldwin 5-endo-tet cyclization. This reaction affords 3-hydroxy-2-alkylpyrrolidines stereospecifically in high yields.
View Article and Find Full Text PDFA concise, protecting-group-free synthesis of the antipsychotic agent (+)-nemonapride has been achieved featuring a europium(III) trifluoromethanesulfonate (Eu(OTf))-catalyzed C4 selective aminolysis of a 3,4-epoxy alcohol by benzylamine and an expedient use of the resulting 4-benzylamino-1,3-diol product for constructing the pyrrolidine skeleton.
View Article and Find Full Text PDFIn our study of the total synthesis of (+)-irciniastatin A, we found a need to develop a method that enables a C3-selective nucleophilic ring opening of 2,3-epoxy alcohol by MeOH, by which we found that the use of combined catalytic amounts of Eu(OTf)3 and 2,6-di-tert-butyl-4-methylpyridine (DTBMP) enables the intended transformation to obtain 3-methoxy-1,2-diol efficiently. Promising features of a protocol that effects a highly regioselective nucleophilic ring opening of 2,3- and 3,4-epoxy alcohols using various nucleophiles including alcohols, thiols, and unprotected amines are described.
View Article and Find Full Text PDFThe organocatalytic one-pot oxidative cleavage of terminal 1,2-diols to one-carbon-unit-shorter carboxylic acids is described. The combination of 1-Me-AZADO (cat.), NaOCl (cat.
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