title: Catalytic asymmetric direct-type 1,4-addition reactions of simple amides.
abstract: The development of catalytic asymmetric direct-type reactions of less acidic carbonyl compounds such as amides and esters has been a challenging theme in organic chemistry for decades. Here we describe the asymmetric direct 1,4-addition reactions of simple amides with α,β-unsaturated carbonyl compounds using a catalytic amount of a novel chiral catalyst consisting of a potassium base and a macrocyclic chiral crown ether. The desired 1,5-dicarbonyl compounds were obtained in high yields with excellent diastereo- and enantioselectivities. This is the first example of a highly enantioselective catalytic direct-type reaction of simple amides. In addition, the structure of the chiral potassium catalyst has been investigated by X-ray crystallographic, dynamic (1)H NMR, and MALDI-TOF MS analyses.
authors: Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: Hirotsugu
authors: H
authors: Suzuki
authors: Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: Io
authors: I
authors: Sato
authors: Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: Yasuhiro
authors: Y
authors: Yamashita
authors: Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: Shū
authors: S
authors: Kobayashi