Application of Chiral Mixed Phosphorus/Sulfur Ligands to Enantioselective Rhodium-Catalyzed Dehydroamino Acid Hydrogenation and Ketone Hydrosilylation Processes
作者:David A. Evans、Forrest E. Michael、Jason S. Tedrow、Kevin R. Campos
DOI:10.1021/ja012639o
日期:2003.3.1
Rh-catalyzed dehydroamino acid hydrogenation and ketone hydrosilylation reactions (eqs 1, 2). After assaying the influence of the substituents at sulfur, the substituents on the ligand backbone, the relative stereochemistry within the ligand backbone, and the substituents at phosphorus, ligands 2c (R = 3,5-dimethylphenyl) and 3 were found to be optimal in the Rh-catalyzed hydrogenation of a variety of alpha-acylaminoacrylates
手性混合磷/硫配体 1-3 已被证明在对映选择性 Rh 催化的脱氢氨基酸氢化和酮氢化硅烷化反应中有效(方程式 1、2)。在测定硫上的取代基、配体骨架上的取代基、配体骨架内的相对立体化学以及磷上的取代基的影响后,发现配体 2c (R = 3,5-二甲基苯基) 和 3 在以高对映选择性 (89-97% ee) 对各种 α-酰基氨基丙烯酸酯进行 Rh 催化氢化。对用于 Rh 催化的酮氢化硅烷化的催化剂进行类似的优化表明,配体 3 为各种芳烷基和二烷基酮提供了最高的对映选择性(高达 99% ee)。