Regiodivergent C−H and Decarboxylative C−C Alkylation by Ruthenium Catalysis: ortho versus meta Position‐Selectivity

Ruthenium(II)biscarboxylate complexes enabled the selective alkylation of C−H and C−C bonds at the ortho‐ or meta‐position. ortho‐C−H Alkylations were achieved with 4‐, 5‐ as well as 6‐membered halocycloalkanes. Furthermore, the judicious choice of the directing group allowed for a full control of ortho‐/meta‐selectivities. Detailed mechanistic studies by experiment and computation were performed and provided strong support for an oxidative addition/reductive elimination process for ortho‐alkylations, while a homolytic C−X cleavage was operative for the meta‐selective transformations.