Enantioselective organocatalytic approach to the synthesis of alpha,alpha-disubstituted cyanosulfones.
Optically pure cyano tert-alkyl sulfones have been obtained by organocatalytic enantioselective Michael addition of alpha-substituted cyanosulfones to vinyl ketones using cinchona alkaloids as catalysts. The best results were obtained for p-trifluorophenylsulfones by using VIII as catalyst in toluene at -40 degrees C. Reactions proved to be applicable for a variety of alpha,beta-unsaturated ketones, affording alpha,alpha-disubstituted cyanosulfones in excellent yields with er's up to 90:10.
Belén Cid
M
M
Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049-Madrid, Spain.
López-Cantarero
Jesús
J
Duce
Sara
S
García Ruano
José Luis
JL
D002384:Catalysis; D002930:Cinchona Alkaloids / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism; D013450:Sulfones / Q000138:chemical synthesis* / Q000737:chemistry
D002930:Cinchona Alkaloids; D007659:Ketones; D013450:Sulfones