C Γ H functionalization is a sustainable and straightforward approach to complex substances. [1] Numerous practical methods for the formation of CΓC, CΓN, and CΓO bonds through direct CΓH activation have been developed using transitionmetal catalysis. The activation of C(sp 2 )ΓH bonds of aromatic compounds provides access to key scaffolds of natural products, drugs, and materials. Double C Γ H activation is a challenging, attractive, and highly economical method to create CΓC biaryl bonds. [2,3] However, the previously developed methods often suffer from selectivity problems in the formation of substituted biaryls and require a great excess of one coupling partner. For the efficient solution to this problem a number of directing groups such as carbonylbased or nitrogen-containing groups have been used. The development of efficient methods for the construction of complex molecules by multiple CΓH functionalization poses a great challenge. Herein, we report our preliminary results on a palladium-catalyzed double CΓH activation using sulfoxide as a new traceless directing group, and its application in a highly regioselective synthesis of polysubstituted dibenzothiophenes through a cascade reaction (Scheme 1).