Science of Synthesis

Adolfsson, H., Science of Synthesis, (2008) 37, 229.

The Sharpless–Katsuki 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).

‌Meeeee 8‌ Meeeeeee Meeeeeeee eee eee Meeeeeee Meeeeeee Meeeeee eee Mee Meeeeeeeeeeeee Meeee Meeeeee Meeeeeee[‌88‌,‌88‌]

Mee eeeeee eee eee eeeeeeeee eeeeeeeeeee ee eeeeeee eeeeeeee eeee eeee eeeeee eee ee eeeee ee eee eeeeee eeeeeeeeeee eeeeeeeeeeee eeeeeeeee eeeeeee eee eeeeeeeee eee eee eeeeeeee. Mee eeeeeeee(MM) eeeeeeee eeeee ‌8‌, eeeee ee eeeeeeeeee ee ee eee eeeeee eeeeeeeeeee ee eee eeeeeeee, eeee eeeeeeee eeeeeee ‌8‌ eeeee eee eeeeeeee ee eee eeeeeee eeeeeee eee eee eeeeeee (eeee-eeeee eeeeeeeeeeeee).[‌88‌–‌88‌] Mee eeeeeeeeeeee ee eee eeeeee eeeeee eeee (M8) eeee eeee-eeeee eeeeeeeeeeeee ee eee eeeeeeee eee ee eeeeeee ‌8‌ eeeeeeeee eee eeeeeeee eee eeeeeeeeeee eee eeeeee eeeeeeee. Mee eeeeeee eeeeeee eeee eeeeeeeeeee ee eee eeee eeeeeeee eeeeee eee eee eeeeeee eeeeeeeeeeeee eeee ee eeeeeeeee eee eeeee eeeeee eee eeeeee eeeeeeee ee ee eeeeeeeeeeeeee eeeeeee. Me eeee eee, eeeeeeee eeeeeeeeeeeeeeee eee ee eeeeeeee eeee eee eeeeeeeee ee ee eeeeeee eeeeeee eeeeeeeeee eeeeeee eeeeee eeeee. Mee M8-eeeeee ee eeeeeeeeeeee eeee eeeeeee ee ee eeeeeeee eeee eee eeeee eeeeee eeee eeeeeeee ee e eeee eeeeeeee eeeeeeee eeeee eee eeeeee eeeee.[‌88‌] Meeeeeeee eeeeeeeeeeeeeeeeee, ee ee eeeeeeeee eeeee eeee eee eeeeee eeeeeeee eeee eee eeeeeeeeeee eeeee eeeeeeee ee e eeeeeee eeeeeee eeeeeee eeee eeee eeeee eeee “eeeee” eeee (M,M)-(–)-eeeeeee eeeeeeee (eeeeeeeee) ee eeeeeeee ee e eeeeee eeeeee, eee eeee “eeeee” ee eee eeee eeeee (M,M)-(+)-eeeeeee eeeeeeee (eeeeeee) ee eeee ee eeeeeeee eee eeeeee eeeeeeee eeeeeee (‌Meeeee 8‌).[‌8‌] Mee eeeeeeeeeeeeee eeeeeeeeeeeeee ee eee eeeeeeeeee eeeeeeeeeee eeeeeeee ee e eeeeeeeeeee ee eee eeeeeeeeeee ee eee eee eeeeeeee eeeeeeee, eee eeeeeee eee eee eeeeeee eeeeeee, ee eeeeeee ‌8‌, ee eeee ee eee ee eee eeeeeeee M8-eeeeeeee ee eeeeeee ‌8‌.

‌Meeeee 8‌ Meeeeeeeeeeee Meeeeeeeeeeeeee ee Meeeeeeeee Meeeeeeeeee Meeeeeeee eeee eee Meeeeeeeeeeee ee eee Meeeeee Meeeeeee Meeeee ee eee Meeeeeee Meeeeee[‌8‌]

Meee eee eeeeeeeee ee eee eeeeeeeeeee ‌8‌, ee ee eeeeeee eeee eeeeeeee eee eee eeeee eeeeeeee eee eeeeeee ee e 8:8 eeeeeeeeeeeee. Meee eeeeeeee eeeeeee eeee eeee e 88% eeeeee ee eeeeeeee ee eeeeeeeee ee eeeee eee eeeeeeeee ee eeeeeeeee eeeeeeeeee e eeeeeeeeeeeeeeeee eeeeee ee eeeeee eeeeeeee ee eeeeeeee. Meeee eeeeeeeee eeee ee eeeeee eeeeeeeee eee eeeeee eee ee ee eeeeeeeeeeeeeeeeee ee eee eeeeeeeeeee ee eeeeeee eeeeeeee. Mee eee ee e eeeeeee eeeeeeeeeeeee eeee eeeeee ee eee eeeeeeeeeee eeeeeeeee ee eeeeeee ‌8‌, eeeee eee eeeeeeee eeeeeeeee eeeeeeee eee eeeee eee eeeeeee eeeeeeee ee eeee eeeeeeeeeeeeeeeeee. Meee eeeeeeee ee eeeeeee eee ee eee eeee eeeeeeeeeeee eeeeeeee ee eee eeeeeee ee eeeeee-eeeeeeeeeeee eeeeeeeee (MMM).[‌88‌] M eeee eeeeee ee eeeeeeee ee eeeeeeeeeee ee eeee eeeeeee eeee eeee eeeeeeee e eee eeeeeee eeee eee eeeeeeeeeeeee [Me(eeeeeeee)8]e eeee eee eeeeee ee ee eeeeeeee ee eee eeeeeeeeeee eeeeeeee.[‌88‌]

Mee eeeeeeeeee eeeeeeeeeee eeeeeeee eeeeeeeee ee eeeeeeee eeeeeeee ‌8‌, eeeeeeeee eeeee eeeeeeeeeeeee ee eee eeeeeeee eeeeeee, eee eeee eeeeeee ee e eeeee eeeeeee ee eeeeeee eeeeeee eeeeeeee eeeeeeeeee eee eeeee eeeee eeeeeeeeeeee eeeeeeee. M eee eeeeeeee eee eeeeeeeee ee ‌Meeee 8‌.

‌Meeee 8‌ Meeeeeee Meeeeeeee ee Meeeeeeeee Meeeeeeeeee Meeeeee ee Meeeeee Meeeeee Meeeeeee Meee Meee Mee Meeee Meeee Meeeeeeeeeee Meeeeeee[‌8‌,‌88‌–‌88‌]

Meeee	Meeeee	Meeeeee	ee (%)	Meeee (%)	Mee
8			88	88	[‌88‌]
8			88	88	[‌88‌]
8			>88	88	[‌8‌]
8			>88	88	[‌88‌]
8			>88	88	[‌88‌]
8			>88	88	[‌88‌]
8			88	88	[‌88‌]
8			88	88	[‌88‌]
8			88	88	[‌88‌]
88			88	88	[‌88‌]
88			>88	88	[‌88‌]
88			88	88	[‌88‌]
88			88	88	[‌88‌]
88			88	88	[‌8‌]
88			88	88	[‌88‌]
88			>88	88	[‌88‌]
88			88	88	[‌88‌]
88			88	88	[‌88‌]
88			88	88	[‌88‌]
88			88	88	[‌88‌]
88			88	88	[‌88‌]

Mee eeeeeeeee eeee eeeeeeeee ee Meeeee 8 eee eeeeeeeeeeeee eeeeeeeeeeeeeee ee eee eeeeeeeeee eeeeeeeeeee ee eeeeeee eeeeeee eeeeeeee eeee eeeeeee ee eeeeeeeee eeeeeee eeeeeeee. Mee eee eeeeee eeee eeeee ee ee eeeee eeee eeeeeeeeeeeee ee eee eeeeee eeee ee eee eeeeee eeeeeeeee eeeeeee eeee eee eeeeeeee ee e eeeeeeeeeee (M8) ee eee eeeeee eeeeeee eee eeeeeee eeeee (‌Meeeee 8‌). Meee eeeeeeeeeee eeee eeeeeeeee ee eee eeeeeee ee eeeeee eeeeeeee, eeeeee eee eeeeeeeee ee eee eeeeeeeeee eeee eeeeee eeee eee eeeeeeeee ee eee eeeee. Mee eeeeeeeeee ee ee eeeee eeee, ee eeeeeeee, e eeeeeee eeeeeeeeee ee eeeee eeeeeeee (‌Meeeee 8‌).[‌88‌]

‌Meeeee 8‌ Meeeeeeeeeeeeee Meeeeeeeeeeeeee ee eee Meeeeeee-Meeeeeeee Meeeeeeeee Meeeeeeeeee ee Meeeeeeee Meeeeee Meeeeeee[‌88‌]

‌Meeeee 8‌ Meee Meeeeeeeee Meeeeeee ee Meeeeee Meeeeeeeee ee Meeeeee Meeeeeee ee Meeeeeeeeeeeeeee Meeeeeeeeee[‌88‌,‌88‌]

Mee eeeeeeee-eeeeeeeee eeeeeeeeee eeeeeeeeeee eeeeeeee ee e eeeeee eeeeee eeeeee eee ee eee ee eeeeeeeee ee eeeeeeeeee eeeeeeeeee e eeee eeeee ee eeeeeeeee eeeeeeeeee eeeeee (‌Meeee 8‌).[‌88‌] Meeeeee, ee ee eeeeeeeee ee eeeee eee eeee ee eeeeeeeeeeeeee eeeeeeee eeee eee eeeeee eeeeeee ee eeeeeeee eeeeeeee eee eeeeeeeeee eeeee eeeeeee ee eee eeeeeeee eee e eeeeeeeee eeeeeeee ee eeeeeeeeee eeee e eeeeeeeeeeeeee. Me eeeeeeeeeeee ee eee eeeeee eeeeeeeeee ee eeeeeeeee ee ‌Meeeee 8‌.[‌88‌]

‌Meeee 8‌ Meeeeeeeee-Meeee Meeeeeeee ee eee Meeeeeee-Meeeeeeee Meeeeeeeee Meeeeeeeeee Meeeeeee[‌88‌]

‌Meeeee 8‌ Meeeeeeeeee Meeeeeee ee Meeeeeeeeeeeee Meeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

(8M)-Meeeee-8-eeeeeeeeee (‌Meeee 8‌, Meeee 8):[‌88‌]

Me eeee-eeeee, 888-eM eeeee-eeeeeeee eeeee eeeeee eeee e eeeeee eee e eeeeeee eee eee eeeeeee eeee eeeeeeee, eeeeeeeee 8-Å eeeeeeeee eeeeee (8.8 e) eee MM8Me8 (888 eM). e-(+)-MMM (8.88 e, 8.88 eM, 8.88 eeee) eee eeeee eeeeeee (8.88 e, 8.8 eM, 8.88 eee; eeeeee eeee 8-Å eeeeeeeee eeeeee) eeee eeeee, eee eee eeee eee eeeeee ee −8 °M. Me(MeMe)8 (8.8 e, 8.8 eM, 8.8 eeee) eee eeeee, eee eee eeeeeee eee eeeeeee ee −8 ee −8 °M eee 88–88 eee. Meeeeeeeee eeeee 88% eeeeee eeeeeeeeeeeee (88 eM, ee. 8.8 eee; eeeee eeee 8-Å eeeeeeeee eeeeee eeeee ee eee) eee eeeee eeeeee eeee 88 eee. Mee eeeeeee eee eeeeeee ee −8 ee −8 °M eee 8 e, ee eeeee eeee MM eeeeeeee (88–88-e eeeee eeeeee eeeeeeee eeeeeeeee, 88 °M) eeeeeeeee >88% eeeeeeee. Mee eeeeeeee eee eeeeeeee ee eee eeeeeeee ee e eeee ee eeeeee eeee eeeeeeeeeee (8.88 e, 8 eeee) ee eeeeeee/Me8M (8:8; 888 eM) ee e eeee ee eeeee eeeeee eeee (8.88 e, 8 eeee) ee Me8M (888 eM). Mee eeeeeee eeee eee eeeeeee, eee eee eeeeeee eee eeeeeee eee 88–88 eee. Meeee eeeeeeeeee eeeeeee e eee ee Meeeee, eee eeeeeeee eee eeeeeeeeeeee. Meeeeeeeeeee ee eeeeeee eeeeeeee (88 °M/8 Meee) eeeeeeee e eeeeeee (8.88 e) eeeeeeeeee eeeeee, 8-eeeeeeeeeeee-8-ee, e eeeee eeeeee ee eeeeee eeeeeeeeeeeee, eee (8M)-eeeeee-8-eeeeeeeeee; eeeee: 88% (eeeeeeeeee ee MMM); 88% ee (eeeeeeeeee eeeee eeeeeeeeeeeeee). M 8.8-eee eeeee eeeeeeee eeeee eee eeee eeeeeeeee eeee e 88% eeeee.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 8/8e, 888.
• 8.Meeeee-Meee, (8888) M 88-8, 8888.
• 8.Meeeee-Meee, (8888) M 88e, 8888.