A chiral acrylate equivalent for metal-free Diels-Alder reactions: endo-2-acryloylisoborneol.
The principle of metal-free activation of enones toward the Diels-Alder reaction with dienes is demonstrated by exploiting the capability of Brønsted acids to activate alpha'-hydroxyenones through hydrogen bonding. The diastereoselective application of such a principle is nicely realized by using a newly designed family of camphor-based chiral enones, which upon catalytic action of either trifluoroacetic or triflic acid lead to the corresponding cycloadducts with high chemical and stereochemical efficiency.
Palomo
Claudio
C
Departamento de Química Orgánica I, Facultad de Química, Universidad del País Vasco, Apdo. 1072, 20080 San Sebastián, Spain. qoppanic@sq.ehu.es
Oiarbide
Mikel
M
García
Jesús M
JM
González
Alberto
A
Lecumberri
Ainara
A
Linden
Anthony
A