Photoreductive Removal of <i>O</i>-Benzyl Groups from Oxyarene <i>N</i>-Heterocycles Assisted by <i>O</i>-Pyridine–pyridone Tautomerism
作者:Aleksandar R. Todorov、Tom Wirtanen、Juho Helaja
DOI:10.1021/acs.joc.7b02775
日期:2017.12.15
groups from oxyarene N-heterocycles at positions capable for 2-/4-O-pyridine–2-/4-pyridone tautomerism. Blue light irradiation, a [Ru] or [Ir] photocatalyst, and ascorbic acid in a water–acetonitrile solution debenzylates a variety of aryl N-heterocycles cleanly and selectively. Ascorbic acid has two functions in the reaction. On the one hand, it protonates the N-heterocycles that reduces their reduction
已经开发出了简便的光还原方案,可以从氧化芳烃N-杂环上的苄基O-保护基团去除能够使2- / 4- O-吡啶-2- / 4-吡啶酮互变异构的位置。蓝光照射,[Ru]或[Ir]光催化剂和水-乙腈溶液中的抗坏血酸可选择性地使各种芳基N-杂环脱苄基。抗坏血酸在反应中具有两个功能。一方面,它使N-杂环质子化,从而显着降低其还原电位,另一方面,它作为牺牲性还原剂。以CPCM-B3LYP / 6-31 + G **水平计算的还原势和自由能垒可以预测所研究底物的反应性。