Transition-Metal-Free and Visible-Light-Mediated Desulfonylation and Dehalogenation Reactions: Hantzsch Ester Anion as Electron and Hydrogen Atom Donor
作者:Micaela D. Heredia、Walter D. Guerra、Silvia M. Barolo、Santiago J. Fornasier、Roberto A. Rossi、María E. Budén
DOI:10.1021/acs.joc.0c01523
日期:2020.11.6
at rt. Alternately, a visible light method has been used for deprotection of N-methyl-N-arylsulfonamides with Hantzsch ester (HE) anion serving as the visible-light-absorbing reagent and electron and hydrogen atom donor to promote the desulfonylation reaction. The HE anion can be easily prepared in situ by reaction of the corresponding HE with KOtBu in DMSO at rt. Both protocols were further explored
已开发出在室温(rt)和无过渡金属条件下进行N-和O-磺酰化的新方法。第一种方法涉及在室温下仅使用二甲基亚砜(DMSO)中的KO t Bu将各种N-磺酰基杂环和苯基苯磺酸盐以良好或优异的收率转化为相应的脱磺酰化产物。或者,已经使用可见光方法用作为可见光吸收剂的Hantzsch酯(HE)阴离子和电子和氢原子供体来促进N-甲基-N-芳基磺酰胺的脱保护,以促进脱磺酰化反应。HE阴离子可轻松就地制备通过在室温下将相应的HE与DMSO中的KO t Bu反应。进一步研究了两种方案的合成范围和机制方面,以合理化脱磺酰化工艺的关键特征。此外,HE阴离子在可见光照射下诱导芳基卤化物的还原脱卤反应。