Chiral Lewis base catalyzed enantioselective acetylcyanation of α-oxo esters
2009 (English)In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, Vol. 23, 3917-3922 p.Article in journal (Refereed) Published
Acetyl cyanide adds to alkyl benzoylformates and to 2-oxoalkanoates to yield enantioenriched acylated cyanohydrins in one step in the presence of a catalytic amount of a chiral base. The reaction is accelerated by Lewis acids and by the addition of a catalytic amount of methanol. Under optimized conditions, 94% of a 94:6 mixture of the O-acetylated and non-protected cyanohydrins was formed from, methyl benzoylformate in the presence of cinchonidine; from, this mixture the acylated compound with 66% ee was isolated in 77% yield. Ethyl pyruvate and ierf-butyl 2-oxobutanoate were more reactive, and essentially full conversion to the products with 69 and 82% ee, respectively, was achieved. The reaction proceeds by a non-selective addition of cyanide ion to give the non-protected cyanohydrin followed by a dynamic kinetic resolution to provide the enantioenriched acetylated product.
Place, publisher, year, edition, pages
2009. Vol. 23, 3917-3922 p.
Acylation; Addition reactions; Asymmetric catalysis; Cyanides; Kinetic resolution; Lewis bases
IdentifiersURN: urn:nbn:se:kth:diva-10366DOI: 10.1002/ejoc.200900055ISI: 000269103600014ScopusID: 2-s2.0-68049139704OAI: oai:DiVA.org:kth-10366DiVA: diva2:216256
Tidigare titel: Chiral Lewis Base-Catalyzed Enantioselective Acetylcyanation of α-Ketoesters
QC 201008182009-05-072009-05-072012-01-18Bibliographically approved