Sequential reactions promoted by manganese: completely stereoselective synthesis of (E)-alpha,beta-unsaturated amides, ketones, aldehydes, and carboxylic acids.
A complete E-selective synthesis of alpha,beta-unsaturated amides through a sequential reaction of a range of dichloroamides with a variety of aldehydes promoted by Rieke manganese (Mn*) is reported. A mechanism based on a sequential aldol-type reaction and a completely stereoselective beta-elimination is proposed to explain these results. The unsaturated amides obtained are readily and efficiently transformed into alpha,beta-unsaturated ketones, aldehydes, or carboxylic acids without loss of the diastereoisomeric purity of the C-C double bond.
Concellón
José M
JM
Departamento de Química Orgánica e Inorgánica, Universidad de Oviedo, Julián Clavería 8, 33071 Oviedo, Spain. jmcg@uniovi.es
Rodríguez-Solla
Humberto
H
Díaz
Pamela
P