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Please login to access the full content or check if you have access via2.12.2.1 Reactions with Chiral Titanium Catalysts
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Liu, L.; Wang, D.; Li, C. -J., Science of Synthesis: Stereoselective Synthesis, (2011) 2, 602.
Enantioselective processes utilizing chiral titanium(IV) complexes have proved to be some of the most powerful transformations available to organic chemists. The addition of O-silyl O-alkyl ketene acetal 8 to aldehydes in the presence of only ca. 2–5 mol% of 1,1′-bi-2-naphthol-based titanium(IV) catalyst 25, which can be prepared from binaphthyl derivative 64 and carboxylic acid 65, yields the aldol products, such as 66, with excellent enantioselectivity (Scheme 28).[24]
Meeeee 88 Meeeeeeeee Meeeeeeee Meeee Meeeeeee Meeeeeeee ee e Meeeee Meeeeeee Meeeeeee[88]
Meeeeeeeeeee Meeeeeeee
Meeee 8-Meeeeee-8-eeeeeeeeeeeeeeee (88); Meeeeee Meeeeeeee:[88]
Me e 8.8 eM eeee ee 88 (8.88 eeeee) ee eeeeeee eee eeeee Me(MeMe)8 (8.88 eeeee). Mee eeeeee eeee eee eeeeeee eee 8 e ee 88 °M eeeeee 8,8-ee-eeee-eeeee-8-eeeeeeeeeeeeee eeee (88; 8.88 eeeee) ee eeeeeee eee eeeee. Meeeeeee eee eeeeeeeee eee ee eeeeeeeeee 8 e ee 88 °M. Mee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee, eee eee eeeee eeeeee eeeeeee ee Me eeeeeeee 88 eee eeeee ee ee Me8M. Meeee eee eeee eee eeee eeeeee ee −88 °M, MeMMM (8 eeeee) eee eee eeeee eeeeee eeeeee 8 (8.8 eeeee) eeee eeeee eeeeeeeeeeee. Mee eeeee eee eeee eeee ee −88 °M eee 8 e eeeeee eee eeeeeeee eee eeeeeeee ee eeeeeee eee eeeeeee eeee 8% ee MeMMM8. Mee eeeeeee eeee eee eeeeeeeee eeee Me8M eee eee eeeeeeee eeeeeee eeeeeeee eeee eeeeee eeee eee. ee MeMe eee eeeee (Me8MM8). Mee eeeeeee eeeeeeee eeee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeee ee ee MMM eee eeeeeee eeee eeeeee MMMM (8–8 eeeee). Mee eeee eee eeeeeeeeeee eeeeeee Me8M eee 8 M ee MMe. Mee eeeeeee eeeee eee eeeeee eeee 8% ee MeMMM8 eee eeee eeee eee. ee MeMe. Mee eeeeeee eee eeee eeeee (Me8MM8) eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeeeeeeeee ee eeeeeeeeeeeeee (eeeeee eee, MM8Me8/eeeeee 88:8 eeee MM8Me8/Me8M 88:8) eeeeeeee eee eeeee eeeee eeeeee; eeeee: eee eeeeeeee; 88% ee eeeee ee eee eeee ee (M)-8,8,8-eeeeeeeee-8-eeeeeee-8-eeeeeeeeeeeeeee eeee [(M)-MMMM] eeeee eeee; [α]M +88.8 (e 8.8, MMMe8).
References
[24] | Meeeeeee, M. M.; Meeeee, M. M.; Mee, M., M. Me. Meee. Mee., (8888) 888, 8888. |