Organocatalytic synthesis of quaternary stereocenter bearing a fluorine atom: enantioselective conjugate addition of α-fluoro-β-ketoesters to nitroalkenes

The catalytic enantioselective conjugate addition reaction of alpha-fluoro-beta-ketoesters to nitroalkenes promoted by chiral bifunctional organocatalysts is described. The treatment of alpha-fluoro-beta-ketoesters with nitroalkenes under mild reaction conditions afforded the corresponding Michael adducts containing a fluorinated quaternary stereogenic center with excellent enantioselectivity (up to >99% ee). (C) 2009 Elsevier Ltd. All rights reserved.