Chiral <i>C</i><sub>2</sub>-Symmetric Ligands with 1,4-Dioxane Backbone Derived from Tartrates: Syntheses and Applications in Asymmetric Hydrogenation
作者:Wenge Li、Jason P. Waldkirch、Xumu Zhang
DOI:10.1021/jo020250t
日期:2002.11.1
Chiral 1,4-diphenylphosphines 5-7 as well as thioether 8 were synthesized from tartrates employing Ley's "BDA" and "Dispoke" methodologies as the key step. Rhodium(I) complexes with 5-7 are efficient catalysts for the asymmetric hydrogenation of beta-substituted enamides and MOM-protected beta-hydroxyl enamides, which furnished chiral amines or beta-amino alcohols with 94-->99% ee. These results indicated
手性1,4-二苯基膦5-7以及硫醚8是由酒石酸盐合成的,采用Ley的“ BDA”和“ Dispoke”方法作为关键步骤。含5-7的铑(I)配合物是有效的催化剂,可用于β-取代的酰胺和MOM保护的β-羟基酰胺的不对称加氢,从而提供了94-> 99%ee的手性胺或β-氨基醇。这些结果表明,具有一般结构2的配体中的1,4-二恶烷骨架在稳定金属-配体螯合物构象中起重要作用。与具有一般结构1的类似配体相比,配体2具有更高的对映选择性。