Asymmetric Direct α-Hydroxylation of β-Oxo Esters by Phase-Transfer Catalysis Using Chiral Quaternary Ammonium Salts
作者:Mingming Lian、Zhi Li、Jian Du、Qingwei Meng、Zhanxian Gao
DOI:10.1002/ejoc.201001175
日期:2010.12
The first enantioselective direct α-hydroxylation of β-oxo esters was developed by using phase-transfer catalysis. 1-Indanone-derived 1-adamantyl (1-Ad) β-oxo esters, in the presence of commercially available cumyl hydroperoxide and a cinchonine-based ammonium salt, resulted in the corresponding products with 69–91 % yield and 65–74 % ee. The reaction had also been successfully scaled-up to a gram
β-氧代酯的第一个对映选择性直接α-羟基化是通过使用相转移催化开发的。1-茚满酮衍生的 1-金刚烷基 (1-Ad) β-氧代酯,在市售的过氧化氢枯基和基于辛可宁的铵盐的存在下,产生了相应的产物,产率 69-91%,产率 65-74% ee。该反应也已成功地放大到克量,并且在不损失对映选择性的情况下获得了类似的产率。