Enantioselective organocatalytic intramolecular aza-Michael reaction: a concise synthesis of (+)-sedamine, (+)-allosedamine, and (+)-coniine.
The intramolecular aza-Michael reaction of carbamates bearing remote alpha,beta-unsaturated aldehydes under organocatalytic conditions took place with good yields and excellent ee's when Jørgensen catalyst IV was used in the process, giving rise to the enantioselective formation of several five- and six-membered heterocycles. The developed methodology was applied to the synthesis of three piperidine alkaloids.
Fustero
Santos
S
Departamento de Química Orgánica, Universidad de Valencia, E-46100 Burjassot, Spain. santos.fustero@uv.es
Jiménez
Diego
D
Moscardó
Javier
J
Catalan
Silvia
S
Pozo
Carlos Del
CD