Ru(II)-Catalyzed\n[1,4]-Sigmatropic Rearrangement and\nIntramolecular Concerted S<sub>N</sub>Ar of Aryl and Heteroarylthio\nDerivatives using Quinoid Carbene

A Ru(II)-catalyzed straightforward and efficient strategy\nhas been\ndeveloped to construct <i>O</i>-alkylated arylnaphthyl thioether\nderivatives using arylthioacetates/arylalkylthioethers with diazonaphthoquinone\nvia a [1,4]-<i>oxa</i> sigmatropic rearrangement. In a complementary\nmethod, heteroaryl thioacetate/heteroaryl alkylthioethers offer <i>O</i>-heteroaryl alkylnaphthyl thioether derivatives via an\ninteresting concerted intramolecular S<sub>N</sub>Ar-type reaction.\nBoth of these methods proceed through the formation of Ru-based quinoid\ncarbene and sulfur ylide, respectively. A detailed mechanistic study\nand DFT calculations reveal that the reaction is going via a concerted\nmanner. Postsynthetic modifications of the synthesized compounds led\nto sulfur-containing polyaromatic heterocycles.