Transfer of 1-alkenyl groups between secondary amines. relative stability and reactivity of enamines from popular organocatalysts.
Enamines from 3-methylbutanal and several Pro- and Phe-derived secondary amines were prepared in DMSO-d6, CD3CN, and CDCl3. For the first time, the relative thermodynamic stabilities of these and other enamines were compared, and rapid exchanges of 1-alkenyl groups were demonstrated. Competition experiments showed that the most favored enamines (without significant steric inhibition of resonance) react more rapidly with electrophiles.
Departament de Química Orgànica, Facultat de Química, Universitat de Barcelona , Diagonal 645, 08028 Barcelona, Catalonia, Spain.
Héctor
H
Carneros
Dani
D
Sánchez
Jaume
J
Vilarrasa