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37.2.1.1.2 Method 2: Titanium-Mediated Asymmetric Epoxidation with Alkyl Hydroperoxides

DOI: 10.1055/sos-SD-037-00140

Adolfsson, H.Science of Synthesis, (200837229.

The SharplessKatsuki asymmetric epoxidation protocol for the enantioselective formation of epoxides from allylic alcohols, being the first major catalytic asymmetric oxidation procedure, stands out as a milestone in asymmetric catalysis.[‌9‌] This classical enantioselective transformation uses alkyl hydroperoxides, typically tert-butyl hydroperoxide, as the terminal oxidant, and the reaction has been widely used in numerous synthetic applications. There are several excellent reviews covering the scope and utility of the asymmetric epoxidation reaction.[‌10‌] The asymmetric epoxidation reaction has, besides outstanding historical value, the extraordinary features of being easily accessed and performed, highly predictable in its outcome, and applicable to a wide range of substrates. The titanium tartrate catalyst 1 is readily accessible from a dialkyl tartrate and a titanium alkoxide [most commonly diethyl tartrate (DET) and titanium(IV) isopropoxide], and the alkyl hydroperoxide used as oxidant is, in general, commercially available (Scheme 1).

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Meeee Meeeee Meeeeee ee (%) Meeee (%) Mee
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References