Formation of Amidinyl Radicals via Visible-Light-Promoted Reduction of <i>N</i>-Phenyl Amidoxime Esters and Application to the Synthesis of 2-Substituted Benzimidazoles
作者:Gang Li、Ru He、Qiang Liu、Ziwen Wang、Yuxiu Liu、Qingmin Wang
DOI:10.1021/acs.joc.9b01158
日期:2019.7.5
We have developed a new method for the synthesis of 2-substituted benzimidazoles via amidinyl radicals generated by visible-light-promoted reduction of N-phenyl amidoxime esters in the presence of an iridium photocatalyst. This is the first report of the use of N-phenyl amidoxime esters as amidinyl radical precursors, and the first use of substituted benzene rings as amidinyl radical acceptors. This
我们已经开发了一种新的方法,该方法通过在铱光催化剂的存在下,由可见光促进的N-苯基a肟肟酯的还原反应生成的via基自由基合成2-取代的苯并咪唑。这是使用N-苯基a肟肟酯作为a基自由基前体的首次报道,也是取代苯环作为a基自由基受体的首次报道。该方法拓宽了底物的应用范围,克服了传统的2-取代苯并咪唑合成方法的缺点,该方法要求苛刻的反应条件,涉及难以制备的取代邻苯二胺底物,并产生酸性废物。