Dipartimento di Scienza e Alta Tecnologia, Università dell'Insubria, via Valleggio 11, 22100 Como, Italy.
DISFARM, Sezione di Chimica Generale e Organica "A. Marchesini" Università degli Studi di Milano, via Venezian 21, 20133 Milano, Italy.
J Org Chem. 2022 Jan 21;87(2):1032-1042. doi: 10.1021/acs.joc.1c02329. Epub 2022 Jan 11.
A dimerization/cyclization reaction of 2-benzylamino-phenols for the direct synthesis of the oxazolo-phenoxazine skeleton is reported. The reaction occurs under copper catalysis in the presence of hypervalent iodine(III), giving selectively the 5-oxazolo[4,5-]phenoxazine compounds. The cascade process, which allows the conversion of the substrates into the tetracyclic products, involves three C-H functionalization steps. Initial oxidation of electron-rich arenes by the hypervalent iodine is essential for the dimerization of substrates, whereas the formation of the five-membered rings is promoted by the copper species. 1-Benzyl-2-phenyl-6-(aryl-benzyl)amino-benzimidazoles are regioselectively obtained using ,'-dibenzyl-phenylenediamines as starting substrates. The fluorescence emission properties of these classes of products have been evaluated.
报道了一种 2-苄氨基苯酚的二聚/环化反应，用于直接合成恶唑并苯并二嗪骨架。该反应在高价碘(III)存在下在铜催化下进行，选择性地得到 5-恶唑并[4,5-]苯并二嗪化合物。该级联过程允许将底物转化为四环产物，涉及三个 C-H 官能化步骤。高价碘对富电子芳环的初始氧化对于底物的二聚化至关重要，而铜物种促进了五元环的形成。使用,'-二苄基-苯二胺作为起始底物，可区域选择性地得到 1-苄基-2-苯基-6-(芳基-苄基)氨基苯并咪唑。评估了这些类别的产物的荧光发射性质。
