Department of Chemistry, University of Pennsylvania, Roy and Diana Vagelos Laboratories, 231 S. 34th Street, Philadelphia, PA, 19104-6323, USA.
Angew Chem Int Ed Engl. 2017 Nov 20;56(47):15073-15077. doi: 10.1002/anie.201709487. Epub 2017 Oct 24.
Described is a facile, scalable route to access functional-group-rich gem-difluoroalkenes. Using visible-light-activated catalysts in conjunction with an arsenal of carbon-radical precursors, an array of trifluoromethyl-substituted alkenes undergoes radical defluorinative alkylation. Nonstabilized primary, secondary, and tertiary radicals can be used to install functional groups in a convergent manner, which would otherwise be challenging by two-electron pathways. The process readily extends to other perfluoroalkyl-substituted alkenes. In addition, we report the development of an organotrifluoroborate reagent to expedite the synthesis of the requisite trifluoromethyl-substituted alkene starting materials.
本文描述了一种简便、可扩展的方法来获得功能基团丰富的gem-二氟烯烃。使用可见光激活的催化剂和一系列碳自由基前体，一系列三氟甲基取代的烯烃经历了自由基脱氟烷基化反应。非稳定的伯、仲和叔自由基可以以收敛的方式引入官能团，否则通过双电子途径会很困难。该过程很容易扩展到其他全氟烷基取代的烯烃。此外，我们还报告了一种有机三氟硼酸盐试剂的开发，以加速所需的三氟甲基取代的烯烃起始原料的合成。
