کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5218577 1383332 2013 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Studies on the true catalyst in the phosphate-promoted desymmetrization of meso-aziridines with silylated nucleophiles
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Studies on the true catalyst in the phosphate-promoted desymmetrization of meso-aziridines with silylated nucleophiles
چکیده انگلیسی

Significant amounts of metal phosphate impurities have been detected by NMR spectroscopy and ICP-OES analysis of synthetic, as well as purchased, samples of VAPOL hydrogen phosphate purified on silica gel. The previously reported VAPOL hydrogen phosphate-catalyzed desymmetrization of meso-aziridines with different silylated compounds, has been re-examined. While metal-free phosphoric acid exhibited low activity and enantioselectivity, calcium and magnesium phosphate salts proved to be the true catalysts in these related processes. Reproducible high enantioselectivities were obtained in the ring-opening of cyclic meso-aziridines with Me3SiX (X=SPh, SePh, N3) employing a 1:1 mixture of calcium and magnesium VAPOL phosphates. The reaction has been successfully extended to Me3SiSBn, Me3SiSMe and Me3SiNCS, giving ring-opened products in high yield and unprecedented moderate to good enantioselectivities.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tetrahedron - Volume 69, Issue 1, 7 January 2013, Pages 50-56
نویسندگان
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