Institute of Chemistry and BioMedical Sciences, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing, 210093, China.
Department of Chemistry and Biochemistry, Texas Tech University , Lubbock, Texas 79409-1061, United States.
J Org Chem. 2018 Jan 19;83(2):644-655. doi: 10.1021/acs.joc.7b02556. Epub 2017 Dec 29.
An asymmetric Mannich-type reaction between chiral N-phosphonyl imines and azlactones [oxazol-5(4H)-ones] has been established under convenient conditions at room temperature. The reaction was performed without using any bases, additives, or catalysts to achieve up to excellent chemical yields and diastereoselectivity for 32 examples. The α-quaternary syn-α,β-diamino acid products were purified simply by washing the crude mixtures with cosolvents, following the group-assisted purification chemistry/technology, without involving traditional chromatography or recrystallization methods. The auxiliary can be readily removed and recycled for reuse. The absolute configuration was unambiguously assigned by X-ray structural analysis.
在室温条件下，通过手性 N-磷酰亚胺与氮杂环丁酮[唑-5(4H)-酮]之间的不对称 Mannich 型反应，可以方便地建立起来。该反应无需使用任何碱、添加剂或催化剂，即可获得高达 32 个实例的优异化学收率和非对映选择性。α-季碳 syn-α,β-二氨基酸产物可以通过简单地用共溶剂洗涤粗混合物，根据辅助基团辅助的纯化化学/技术，而无需涉及传统的色谱或重结晶方法，来进行纯化。该辅助基团可以很容易地被去除并回收再利用。通过 X 射线结构分析，可以明确地确定绝对构型。
