Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States.
Chemistry Institute, University of Campinas, C.P. 6154, CEP 13083-970 Campinas, São Paulo, Brazil.
J Org Chem. 2020 Mar 20;85(6):4153-4164. doi: 10.1021/acs.joc.9b03341. Epub 2020 Feb 27.
Diazenes are valuable compounds that have found broad applicability because of their optical and biological properties. We report the synthesis of alkylaryldiazenes via formal, photoredox-catalyzed, deformylative C-N bond formation. The procedure employs dihydropyridines for the generation of alkyl radicals, which are then trapped by diazonium salts and reduced to the corresponding diazenes. Control experiments were performed to confirm the involvement of radicals in the mechanism. The reaction can be carried out at room temperature and employs readily available reagents; the mild conditions allowed the use of highly functionalized substrates. There was no observed tautomerization of the diazenes to the corresponding arylhydrazones.
重氮化合物是一类具有广泛应用价值的化合物，因为它们具有光学和生物学性质。我们报告了通过形式、光氧化还原催化、去甲酰基 C-N 键形成来合成芳基烷基重氮化合物。该方法使用二氢吡啶来产生烷基自由基，然后将其捕获到重氮盐中，并还原为相应的重氮化合物。控制实验证实了自由基在反应机制中的参与。该反应可以在室温下进行，并使用易得的试剂；温和的条件允许使用高度官能化的底物。没有观察到重氮化合物向相应的芳基腙的互变异构。
