Silylarylation of Alkenes via meta-Selective C–H Activation of Arenes under Ruthenium/Iron Cooperative Catalysis: Mechanistic Insights from Combined Experimental and Computational Studies

Organosilicons are privileged skeletons in the domains of pharmaceutical chemistry, organic synthesis, and materials science. Hence, investigating catalytic techniques for the synthesis of organosilicon compounds has received a great deal of emphasis. Carbosilylation of alkenes is an efficient technique to introduce diverse molecular architectures containing silicon into the chemical space. However, organohalides and pseudohalides are prerequisites for most of the existing carbosilylation protocols. On the other hand, the utilization of C–H activation has been sowing the seeds for the successful development of intricate molecular scaffolds. In this regard, the synthetic accessibility of complexed organosilicon derivatives by the carbosilylation of alkenes through the catalytic meta-C–H activation approach has remained intangible. Herein, we present a three-component strategy of arylsilylation of olefins with (het)arenes and silanes by integrating the iron-catalyzed silyl radical generation, coupled to intrinsic reactivity of the silyl radical with an alkene, to the ruthenium-catalyzed meta-C–H functionalization of (het)arene, leading to the targeted cross-coupled carbosilylated product. In addition, theoretical investigations with state-of-the-art dispersion corrected density functional theory at B3PW91-D3/Def2TZVP/CPCM(PhCF3) shed intriguing insights on selectivity and the probable mechanistic pathway of the underexplored cooperative 3d/4d transition metal catalysis, such as the formation of the silyl radical and its addition to the alkene catalyzed by iron, followed by meta-selective C–H functionalization of the ruthenium bound arene, furnishing C4 substituted (het)arene functionalized organosilicon compounds.