Novel Disaccharide Chiral Ligands Derived from<i>α</i>,<i>α</i>-Trehalose and Their Applications to Asymmetric Hydrogenation of Enamides
作者:Koji Yonehara、Tomohiro Hashizume、Kouichi Ohe、Sakae Uemura
DOI:10.1246/bcsj.71.1967
日期:1998.8
New chiral diphosphinite ligands such as 4,6 : 2′,3′ : 4′,6′-tri-O-cyclohexylidene-2,3-di-O-diphenylphosphino-α,α-trehalose (1), 3,3′-di-O-benzyl-4,6 : 4′,6′-di-O-benzylidene-2,2′-di-O-diphenylphosphino-α,α-trehalose (2), 4,6 : 4′,6′-di-O-benzylidene-2,2′-di-O-diphenylphosphino-3,3′-di-O-methyl-α,α-trehalose (3), and 2,2′-di-O-benzyl-4,6 : 4′,6′-di-O-benzylidene-3,3′-di-O-diphenylphosphino-α,α-trehalose (4) were prepared from α,α-trehalose which is an inexpensive natural reserve sugar. These ligands work as chiral ligands for Rh-catalyzed hydrogenation of α-acetamidoacrylic and cinnamic acid derivatives to afford both enantiomers of amino acids up to 84%ee (S) and 72%ee (R).
新的手性二膦配体,如 4,6 : 2′,3′ : 4′,6′-tri-O-cyclohexylidene-2,3-di-O-diphenylphosphino-α,α-trehalose (1)、3,3′-di-O-苄基-4,6 :4′,6′-二-O-亚苄基-2,2′-二-O-二苯基膦-α,α-三卤糖 (2)、4,6 :4′,6′-二-O-亚苄基-2,2′-二-O-二苯基膦-3,3′-二-O-甲基-α,α-三卤糖 (3),以及 2,2′-二-O-苄基-4,6 :4′,6′-di-O-benzylidene-3,3′-di-O-diphenylphosphino-α,α-trehalose (4)。这些配体可用作 Rh 催化的 α-乙酰氨基丙烯酸和肉桂酸衍生物氢化反应的手性配体,从而得到高达 84%ee (S) 和 72%ee (R) 的氨基酸对映体。