Chiral 1,1'-binaphthyl-2,2'-diammonium salt catalysts for the enantioselective Diels-Alder reaction with alpha-acyloxyacroleins.
[reaction: see text] A diammonium salt of chiral 1,1'-binaphthyl-2,2'-diamine and trifluoromethanesulfonimide (Tf(2)NH) shows excellent catalytic activity and enantioselectivity for the Diels-Alder reaction of alpha-acyloxyacroleins with cyclic dienes. For example, in the presence of 5 mol % of the ammonium catalyst, the Diels-Alder reaction of alpha-(cyclohexanecarbonyloxy)acrolein with cyclopentadiene proceeded in EtCN at -75 degrees C to give the adducts in 88% yield with 92% exo and 91% ee. This catalyst can be easily prepared in situ by mixing the commercially available chiral diamine and Tf(2)NH.
Sakakura
Akira
A
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Japan.
Suzuki
Kenji
K
Nakano
Kazuhiko
K
Ishihara
Kazuaki
K