Synthetic Application and Structural Elucidation of Axially Chiral Dicarboxylic Acid: Asymmetric Mannich-type Reaction with Diazoacetate, (Diazomethyl)phosphonate, and (Diazomethyl)sulfone
作者:Takuya Hashimoto、Hidenori Kimura、Hiroki Nakatsu、Keiji Maruoka
DOI:10.1021/jo2005999
日期:2011.8.5
acids in organic chemistry, have rarely been used as chiral Brønsted acid catalysts. In this context, we developed axially chiral dicarboxylic acid and evaluated its catalytic activity in asymmetric Mannich-type reaction of aromatic aldehyde-derived N-Boc imines and tert-butyl diazoacetate. To demonstrate the remarkable generality of this catalytic system, tert-butyl diazoacetate was replaced with its
过去十年见证了手性布朗斯台德酸催化的新兴研究领域。然而,羧酸,可以说是有机化学中最普通的酸,很少用作手性布朗斯台德酸催化剂。在这种情况下,我们开发了轴向手性二羧酸,并评估了其在芳香醛衍生的N-Boc亚胺与重氮叔丁基叔丁基酯的不对称曼尼希型反应中的催化活性。为了证明这种催化体系具有非凡的通用性,叔用其磷和硫类似物(重氮甲基)膦酸酯和(重氮甲基)砜代替重氮乙酸丁酯,可以在相同的反应条件下,以高对映选择性获得合成上有价值的手性β-氨基膦酸酯和β-氨基砜。与吡啶衍生物配合的轴向手性二羧酸的X射线晶体学分析显示其独特的内部氢键,该性质为其独特的酸度和手性支架奠定了基础。