Sulfate Radical Anion (SO<sub>4</sub><sup>•–</sup>) Mediated C(sp<sup>3</sup>)–H Nitrogenation/Oxygenation in <i>N</i>-Aryl Benzylic Amines Expanded the Scope for the Synthesis of Benzamidine/Oxazine Heterocycles
作者:Joydev K. Laha、K. S. Satyanarayana Tummalapalli、Akshay Nair、Nidhi Patel
DOI:10.1021/acs.joc.5b01872
日期:2015.11.20
A transition-metal-free, K2S2O8-mediated intra-molecular, oxidative nitrogenation/oxygenation of C(sp(3))-H in N-aryl benzylic amines followed by oxidation at the benzylic center has been developed for the synthesis of benzamidine/benzoxazine heterocycles, providing an expedient access to quinazolin-4(3H)-ones, N-aryl-2-arylbenzimidazoles, and 4H-3,1-benzoxazin-4-ones. A considerable amount of work dealing with the mechanistic study to understand the crucial intramolecular cyclization step largely favors an iminium ion as the key intermediate.