Highly Efficient Asymmetric Synthesis Usomg Organocatalyst Derived From(S)-proline

1 Results Much effort has been focused on organocatalytic asymmetric synthesis in these several years. We have already documented highly efficient organocatalytic asymmetric acylation of a wide variety of racemic alcohols and meso-diols catalyzed bya chiral 1,2-diamine derived from (S)-proline[1]. (S)-Homoproline seems to be a potentially interesting organocatalyst, but no examples using (S)-homoproline itself in asymmetric synthesis has been reported. We have accomplished an efficient and practical synthesis of (S)-homoproline, which is a one-carbon homologated proline, starting from (S)-proline in 7 steps. And then we have developed a novel asymmetric Michael additionreaction of ketones to β-nitrostyrene and its derivatives using (S)-homoproline as a chiral organocatalyst. The reaction was performed in a highly diastereoselective and enantioselective manner over 90% ee[2].