Asymmetric Diels-Alder Reaction of α-Substituted and β,β-Disubstituted α,β-Enals via Diarylprolinol Silyl Ether for the Construction of All-Carbon Quaternary Stereocenters.
The asymmetric Diels-Alder reaction of α-substituted acrolein proceeds in the presence of the trifluoroacetic acid salt of trifluoromethyl-substituted diarylprolinol silyl ether to afford the exo-isomer with both excellent diastereoselectivity and high enantioselectivity. In the Diels-Alder reaction of a β,β-disubstituted α,β-unsaturated aldehyde, good exo-selectivity and excellent enantioselectivity was obtained when the perchloric acid salt of the bulky triisopropyl silyl ether of trifluoromethyl substituted diarylprolinol was employed as an organocatalyst in the presence of water. In both cases, all-carbon quaternary stereocenters are constructed enantioselectively.
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan. yhayashi@m.tohoku.ac.jp.|Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan. yhayashi@m.tohoku.ac.jp.
Yujiro
Y
Hayashi
Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan.
Bojan P
BP
Bondzic
Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan.
Tatsuya
T
Yamazaki
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan.
Yogesh
Y
Gupta
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan.
Shin
S
Ogasawara
Faculty of Advanced Life Science, Frontier Research Center for Advanced Material and Life Science, Hokkaido University, Kita 21 Nishi 11, Sapporo, 001-0021, Japan.
Tohru
T
Taniguchi
Faculty of Advanced Life Science, Frontier Research Center for Advanced Material and Life Science, Hokkaido University, Kita 21 Nishi 11, Sapporo, 001-0021, Japan.
Kenji
K
Monde
Diels-Alder reaction; all-carbon quaternary stereocenter; asymmetric reaction; chirality; organocatalysis