Asymmetric synthesis of pre-protected α,α-disubstituted amino acids from tert-butanesulfinyl ketimines
作者:George Borg、Masao Chino、Jonathan A Ellman
DOI:10.1016/s0040-4039(00)02300-5
日期:2001.2
method for the asymmetric synthesis of pre-protected α,α-disubstituted amino acids is described. 5-Methylfuryllithium is added into sulfinyl ketimines 1 in the presence of AlMe3 to afford the sulfinamides 2 in 75–97% yields and with diastereoselectivities ranging from 75:25 to 99:1. Subsequent oxidation with RuCl3/NaIO4 affords tert-butanesulfonyl (Bus)-protected α,α-disubstituted amino acids 3 in 62–69%
描述了一种不对称合成预保护的α,α-二取代氨基酸的方法。5- Methylfuryllithium加入到亚硫酮亚胺1中阿尔梅的存在3,得到亚磺酰胺2在75-97%的产率和非对映选择性与范围从75:25至99:1。用的RuCl随后氧化3 /的NaIO 4,得到叔-butanesulfonyl(总线)保护的α,α-二取代的氨基酸3在62-69%的产率。总线保护的氨基酸容易形成酰胺键,此后可以用TfOH / CH 2 Cl 2除去总线基团,得到游离胺。