Stereocontrolled Synthesis of 1,4‐Dicarbonyl Compounds by Photochemical Organocatalytic Acyl Radical Addition to Enals
作者:Giulio Goti、Bartosz Bieszczad、Alberto Vega‐Peñaloza、Paolo Melchiorre
DOI:10.1002/anie.201810798
日期:2019.1.21
We report a visible-light-mediated organocatalytic strategy for the enantioselective acyl radical conjugate addition to enals, leading to valuable 1,4-dicarbonyl compounds. The process capitalizes upon the excited-state reactivity of 4-acyl-1,4-dihydropyridines that, upon visible-light absorption, can trigger the generation of acyl radicals. By means of a chiral amine catalyst, iminium ion activation
我们报告了对映体的对映体选择性酰基自由基共轭物的可见光介导的有机催化策略,导致有价值的1,4-二羰基化合物。该方法利用了4-酰基-1,4-二氢吡啶的激发态反应性,该吸收性在可见光吸收后可以触发酰基自由基的产生。通过手性胺催化剂,对亚胺的亚胺离子活化可确保立体选择性自由基阱。我们还证明了这种酰化过程与第二种催化剂控制的成键事件的组合如何使所选择的2,3-取代的1,4-二羰基产物的所有可能的立体异构体的全部基质有选择地进入。