Département de Chimie Moléculaire (SERCO) UMR 5250, ICMG FR-2607, CNRS-Université Joseph Fourier , BP 53, 38041 Grenoble Cedex 09, France.
Org Lett. 2014 Apr 4;16(7):1936-9. doi: 10.1021/ol500483t. Epub 2014 Mar 21.
Original acyclic (E)-α,α-dialkylketonitrones bearing a chiral auxiliary on their nitrogen atom were synthesized and successfully employed for the asymmetric synthesis of α,α-disubstituted amino acids using regio- and stereocontrolled 1,3-dipolar cycloaddition reactions with vinyl ethers. N-Glycosyl chiral auxiliaries were found to provide excellent exo- and π-facial stereocontrol. The obtained enantiopure cycloadducts were selectively transformed into functional α,α-disubstituted amino acids and related β-peptides through the highly regioselective opening of an intermediate quaternary anhydride.
我们合成了具有手性辅助基的原始非循环（E）-α，α-二烷基酮亚硝酮，并成功地将其用于通过区域和立体控制的 1,3-偶极环加成反应与乙烯基醚合成α，α-二取代氨基酸。发现 N-糖基手性辅助基可提供出色的外向和π-面立体控制。通过高度区域选择性地打开中间的四元酸酐，获得的对映纯环加成产物可选择性地转化为功能性α，α-二取代氨基酸和相关的β-肽。
