Tabor John R, Obenschain Derek C, Michael Forrest E
University of Washington , Department of Chemistry , Box 351700, Seattle , Washington 98195-1700 , USA . Email:
Chem Sci. 2019 Dec 26;11(6):1677-1682. doi: 10.1039/c9sc05335b. eCollection 2020 Feb 14.
A new selenophosphoramide-catalyzed diamination of terminal- and -1,2-disubstituted olefins is presented. Key to the success of this transformation was the introduction of a fluoride scavenger, trimethylsilyl trifluoromethanesulfonate (TMSOTf), to prevent a competitive -elimination pathway, as was the use of a phosphoramide ligand on selenium to promote the desired substitution reaction. A screen of catalysts revealed that more electron-rich phosphine ligands resulted in higher yields of the desired product, with selenophosphoramides giving the optimal results. A broad range of substrates and functional groups were tolerated and yields were generally good to excellent. For ()-1,2-disubstituted olefins, diastereoselectivities were always high, giving exclusively anti products. The conditions were also applied to substrates bearing internal nucleophiles such as esters and carbonates, giving rise to 1,2-aminoesters and cyclic carbonates, respectively.
本文介绍了一种新型硒代磷酰胺催化的末端烯烃和1,2-二取代烯烃的双胺化反应。该转化成功的关键在于引入氟化物清除剂三甲基甲硅烷基三氟甲磺酸酯(TMSOTf)以防止竞争性的β-消除途径,以及在硒上使用磷酰胺配体来促进所需的取代反应。催化剂筛选表明,电子密度更高的膦配体可使所需产物的产率更高,其中硒代磷酰胺给出了最佳结果。该反应对多种底物和官能团具有耐受性,产率通常良好至优异。对于(E)-1,2-二取代烯烃,非对映选择性始终很高,仅生成反式产物。该反应条件还适用于带有内部亲核试剂(如酯和碳酸酯)的底物,分别生成1,2-氨基酯和环状碳酸酯。