Enantioselective direct aldol-type reaction of azlactone via protonation of vinyl ethers by a chiral Brønsted acid catalyst.
Highly enantio- and diastereoselective direct aldol-type reaction of azlactones with oxocarbenium ions generated by protonation of vinyl ethers using a chiral phosphoric acid catalyst is presented. The method provides efficient access to biologically and pharmaceutically intriguing beta-hydroxy-alpha-amino acid derivatives having a quaternary stereogenic center at the alpha-carbon atom.
Terada
Masahiro
M
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan. mterada@mail.tains.tohoku.ac.jp
Tanaka
Hiroyasu
H
Sorimachi
Keiichi
K