Enantioselective metal-free reduction of ketones by a user-friendly silane with a reusable chiral additive

• Published in: Tetrahedron letters Vol. 59; no. 29; pp. 2839 - 2843
• Main Authors: Varjosaari, Sami E., Skrypai, Vladislav, Herlugson, Sharon M., Gilbert, Thomas M., Adler, Marc J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 18-07-2018
• Subjects: Asymmetric ketone reduction; Hydrosilylation; Synthesis of chiral alcohols; Synthesis of chiral alcohols; Hydrosilylation; Asymmetric ketone reduction
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2018.06.032

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•Asymmetric reduction of ketones using easy-to-handle and inexpensive silatrane.•Commercially available 1,2-aminoalcohols served to induce chirality (ees up to 86%).•Chiral additives are used stoichiometrically, but recyclable (with full activity).
1-Hydrosilatrane, a safe and easy-to-handle reducing reagent that can be inexpensively accessed, has been shown to reduce prochiral ketones asymmetrically in the presence of chiral 1,2-aminoalcohols with ees ranging from 8% to 86%. The best result was achieved using ephedrine as the source of chirality, which is readily commercially available. The additive can be recovered through extraction and reused without any erosion of enantioselectivity.