Santra Surojit, Maji Ujjwal, Guin Joyram
School of Chemical Sciences , Indian Association for the Cultivation of Science , 2A & 2B Raja S. C. Mullick Road , Jadavpur , Kolkata 700032 , India.
Org Lett. 2020 Jan 17;22(2):468-473. doi: 10.1021/acs.orglett.9b04232. Epub 2020 Jan 8.
Herein, we describe a method for the catalytic enantioselective α-amination of α-substituted acyclic 1,3-ketoamides and 1,3-amidoesters that affords the products possessing N-substituted quaternary stereocenters with a chiral N-heterocyclic carbene (NHC). The reaction is based on the utilization of an intrinsic Brønsted base characteristic of NHC that enables the catalytic formation of a chiral ion pair comprising the enolate and the azolium ion. A series of challenging open-chain α-substituted 1,3-dicarbonyls are aminated via this method with ee's of ≤99%.
在此,我们描述了一种用于α-取代的无环1,3-酮酰胺和1,3-酰胺酯的催化对映选择性α-胺化反应的方法,该方法使用手性N-杂环卡宾(NHC)得到具有N-取代季碳立体中心的产物。该反应基于利用NHC固有的布朗斯特碱特性,从而能够催化形成由烯醇盐和唑鎓离子组成的手性离子对。通过该方法对一系列具有挑战性的开链α-取代1,3-二羰基化合物进行胺化反应,对映体过量值(ee)≤99%。