Short and Efficient Synthesis of Optically Active N-Tosyl Aziridines from 2-Amino Alcohols
نویسندگان
چکیده
Two alternative and complementary one-pot procedures for the direct transformation of 2-amino alcohols to N-tosyl aziridines are presented. The unsubstituted parent compound and its less hindered homologues can be obtained in high yields by tosylation and in situ cyclisation effected by potassium hydroxide in water/dichloromethane. Higher substituted amino alcohols give better yields using potassium carbonate in acetonitrile. Both procedures use simple inorganic bases and produce only inorganic salts as byproducts.
منابع مشابه
Enantiomerically pure 2-aryl(alkyl)-2-trifluoromethylaziridines: synthesis and ring opening with selected O- and N-nucleophiles.
We report herein the synthesis of enantiomerically pure 2-phenyl- and 2-ethyl-2-trifluoromethylaziridines by Mitsunobu-type cyclisation of the corresponding N-protected amino alcohols, and our results regarding their ring opening with selected nucleophiles. Under basic conditions, N-tosyl aziridines have been regioselectively opened at the less hindered carbon. Under acidic conditions, the regi...
متن کاملOrganocatalytic asymmetric ring-opening of aziridines.
The organocatalytic ring-opening of N-tosyl protected aziridines by beta-ketoesters under chiral PTC-conditions, leading to the formation of optically active aminoethyl functionalised compounds with up to 99% ee, has been developed.
متن کاملSynthesis of 2,5-disubstituted 6-azaindoles from substituted aziridines via intramolecular cyclization.
A new and efficient preparation of pharmacologically and biologically important 2,5-disubstituted 6-azaindoles was achieved from cyclizations of aziridin-2-yl dipropargylic alcohols as adducts of two propargyl groups to ethyl 1-benzylaziridine-2-carboxylate. The sequential cyclizations include pyrrole formation and a novel base-catalyzed intramolecular acetylenic Schmidt reaction.
متن کاملNew catalysts for the transition-metal-catalyzed synthesis of aziridines.
Aziridines are especially in demand because of their natural occurrence in diverse biologically active compounds and their manifold transformations in chemical reactions. The ring constraint renders them very reactive substances. In the presence of nucleophiles (N, O, S, C nucleophiles, and halides) they undergo ring-opening, they are used for [3+2] cycloadditions and [3+3] annulations, and the...
متن کاملMicrowave-assisted regioselective ring opening of non-activated aziridines by lithium aluminium hydride.
A new synthetic protocol for the LiAlH(4)-promoted reduction of non-activated aziridines under microwave conditions was developed. Thus, ring opening of 2-(acetoxymethyl)aziridines provided the corresponding beta-amino alcohols, which were then used as eligible substrates in the synthesis of 5-methylmorpholin-2-ones via condensation with glyoxal in THF. The same procedure was applied for the pr...
متن کامل