Sharpless epoxidation mechanistic details

Fig 3.36. Mechanistic details of Sharpless epoxidations, part I the actual oxidant is a stereouniform tert-butyl hydroperoxide complex of a titanium tartrate "dimer" with the least hindrance possible. 

Fig. 3.37. Mechanistic details of Sharpless epoxidations, part II preferred transition state of enantioselective epoxidations of achiral primary allylic alcohols in the presence of l-(+)-DET (top) or d-(-)-DET (bottom).

The first practical asymmetric epoxidation was reported by Katsuki and Sharpless.416 The catalyst that was used in the epoxidation of allylic alcohols by (Bu O was prepared in situ with Ti(OlV)4 and diethyltartrate. Since then, synthetic applications and mechanistic details of these reactions have been widely explored and utilized.564,565 Only a sampling of relevant reports have been cited.416,566-575... 

The most widely used system in industry for catalytic asymmetric epoxidation is known as Sharpless Asymmetric Epoxidation (SAE) (Figure 14.13). While key mechanistic insights will not be covered here as they have been described in detail in previous reviews, our focus will be on the application of this directed epoxidation in an industrial setting. Notably, SAE has been utilised for process-scale preparation of raw materials and as part of... 

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