Desymmetrization of epoxide

Inaba and coworkers reported that a Ti-BINOL complex is an effective catalyst for the desymmetrization of epoxide 44 using primary amines as nucleophiles. Of significant note is the efficiency of this reaction, with only 1 mol% catalyst necessary to attain high yields and selectivities [Eq. (10.11)]. Unfortunately, this epoxide is uniquely effective in this reaction. Cycloheptene oxide, dihydrofuran oxide, and an acyclic version of 44 each provided negligible yields under these reaction conditions ... 

The Lewis acid-catalyzed reaction of epoxides with cyanotrimethylsilane (Me3SiCN) forms /3-siloxy nitriles.252 Highly enantioselective desymmetrization of / >-epoxides with Me3SiCN can be achieved by chiral Ti and Yb catalysts (Equation (67)).255 256... 

A number of useful enantioselective syntheses can be performed by attaching a chiral auxiliary group to the selenium atom of an appropriate reagent. " Examples of such chiral auxiliaries include (49-53). Most of the asymmetric selenium reactions reported to date have involved Inter- or intramolecular electrophilic additions to alkenes (i.e. enantioselective variations of processes such as shown in equations (23) and (15), respectively) but others include the desymmetrization of epoxides by ringopening with chiral selenolates, asymmetric selenoxide eliminations to afford chiral allenes or cyclohexenes, and the enantioselective formation of allylic alcohols by [2,3]sigmatropic rearrangement of allylic selenoxides or related species. 

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