Metal-Free Diaryl Etherification of Tertiary Amines by Ortho-C(sp2)-H Functionalization for Synthesis of Dibenzoxazepines and -ones.

A phenyliodine(III) diacetate mediated umpolung reactivity of the tertiary amines with suitably substituted o-hydroxybenzyl and phenyl groups is exploited to facilitate o-C(sp2)-H functionalization to afford diaryl ethers. The presence of an o-CHO and secondary amine functionalities in the resulting diaryl ether, generated in situ, were utilized for synthesis of dibenzoxazepines and dibenzoxazepinones. Mild conditions and relative broad substrate scope, and potential for further diversification of the diaryl ethers are highlights of this methodology.