Cook Andrea M, Wolf Christian
Department of Chemistry, Georgetown University, 37th and O Streets, Washington, DC, 20057, USA.
Angew Chem Int Ed Engl. 2016 Feb 18;55(8):2929-33. doi: 10.1002/anie.201510910. Epub 2016 Jan 25.
The asymmetric addition of terminal ynamides to trifluoromethyl ketones with a readily available chiral zinc catalyst gives CF3 -substituted tertiary propargylic alcohols in up to 99 % yield and 96 % ee. The exclusion of organozinc additives and base as well as the general synthetic utility of the products are key features of this reaction. The value of the β-hydroxy-β-trifluoromethyl ynamides is exemplified by selective transformations to chiral Z- and E-enamides, an amide, and N,O-ketene acetals. The highly regioselective hydration, stereoselective reduction, and hydroacyloxylation reactions proceed with high yields and without erosion of the ee value of the parent β-hydroxy ynamides.
使用一种易于获得的手性锌催化剂,将末端炔酰胺不对称加成到三氟甲基酮上,可得到产率高达99%且对映体过量值(ee)达96%的CF3取代的叔炔丙醇。排除有机锌添加剂和碱以及产物的一般合成实用性是该反应的关键特征。β-羟基-β-三氟甲基炔酰胺的价值体现在其可选择性转化为手性Z-和E-烯酰胺、一种酰胺以及N,O-乙烯酮缩醛。高度区域选择性的水合、立体选择性还原和氢酰氧基化反应以高产率进行,且不会降低母体β-羟基炔酰胺的ee值。