Organocatalytic Enantioselective Protonation of Silyl Enolates Mediated by Cinchona Alkaloids and a Latent Source of HF

• Published in: Angewandte Chemie (International ed.) Vol. 46; no. 37; pp. 7090 - 7093
• Main Authors: Poisson, Thomas, Dalla, Vincent, Marsais, Francis, Dupas, Georges, Oudeyer, Sylvain, Levacher, Vincent
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley-VCH Verlag 01.01.2007; WILEY-VCH Verlag; WILEY‐VCH Verlag; Wiley
• Subjects: alkaloids; Chemical Sciences; Chemistry; Chemistry, Multidisciplinary; enantioselectivity; hydrogen fluoride; ketones; Organic chemistry; organocatalysis; Physical Sciences; Science & Technology; enantioselectivity; REAGENT; alkaloids; hydrogen fluoride; ALDEHYDES; DECARBOXYLATION; ketones; organocatalysis; AMMONIUM BIFLUORIDES; ETHERS; ESTERS; CATALYTIC ASYMMETRIC PROTONATION; CHIRAL BRONSTED ACID; DERIVATIVES; Alkaloids; Hydrogen fluoride; Ketones; Enantioselectivity; Organocatalysis
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.200701683

Hidden benefits: The enantioselective organocatalytic protonation of silyl enolates has been achieved by using readily available cinchona alkaloid catalysts (1) and a latent source of HF that delivers “at will” the active catalytic hydrogen fluoride salt (1‐HF). This approach leads to enantioselective proton transfer with high enantioselectivities of up to 92 % under mild, neutral, and metal‐free conditions (see scheme, TMS=trimethylsilyl).