Ru(II)-Catalysed [1,4]-Sigmatropic Rearrangement and Intramolecular SNAr Reaction of Aryl and Heteroarylthioacetates using Quinoid Carbene

A Ru(II)-catalyzed straightforward and efficient strategy has been developed to construct O-alkylated arylnaphthyl thioether derivatives using α-thioesters and diazonaphthoquinone via an unprecedented [1,4]-oxa sigmatropic rearrangement. A detailed mechanistic study reveals that the reaction is going through a concerted manner. In a complementary method, heteroarylacetate offers O-heteroaryl alkylnaphthyl thioether derivatives via a novel concerted intramolecular SNAr-type reaction. Both these methods proceed through the formation of quinoid carbene and sulfur ylide respectively.