Science of Synthesis

Matsumoto, K.; Katsuki, T.; Arends, I. W. C. E., Science of Synthesis: Stereoselective Synthesis, (2011) 1, 104.

Yangʼs ketone (‌72‌, R1 = H) has a C2-symmetric axially chiral binaphthyl backbone, which induces high enantioselectivity in the epoxidation of substituted trans-stilbene derivatives (‌Scheme 50‌).[‌119‌] The use of derivatives of this chiral ketone modified with chloride, bromide, or acetal groups at the C3 and C3′ positions leads to higher asymmetric induction.[‌120‌,‌121‌] In the reaction of E-disubstituted and trisubstituted alkenes, high enantioselectivities (up to 95 and 81% ee, respectively) have been achieved. This catalytic system can be used in the asymmetric epoxidation of electron-deficient alkenes. It can also be used in the preparation of methyl (2R,3S)-3-(4-methoxyphenyl)glycidate (‌73‌, R2 = 4-MeOC6H4; R3 = H; R4 = CO2Me), a key pharmaceutical intermediate, in 89% yield and 77% ee.[‌122‌]

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References