Ad irect CÀHs ilylation of electron-deficient heteroarenes was achieved via ar adicalr eaction between pyridines or other N-heterocycles and hydrosilanes in the presence of acetic acid, di-tert-butyl peroxide,a nd tertbutyl mercaptan. The present approach allows the direct introductiono ft rialkylsilyl substituents at the ortho-position of variouselectron-deficient heteroarenes.Arylsilanes are not only structurally important in materials science, polymer synthesis, andm edicinal chemistry,t hey also represent versatile synthetic intermediates. [1, 2] Classically,a rylsilanes are obtained from the reaction of silicon electrophiles with aryl Grignard or lithium reagents. [3] However,t his approach often suffers from significant synthetic limitations, which include the requirement of the pre-functionalizationo f arenes, functional (in)compatibility,a nd/or the use of stoichiometric quantities of organometallic reagents. Thus, the development of alternative strategies for the synthesis of arylsilanes is highly desirable.Recently,t he direct CÀHs ilylation of (hetero)arenes with hydrosilanes has emerged as an atom-economical alternative for the synthesis of arylsilanes,a nd this approach has been successfully applied to the regioselective CÀHs ilylation of electron-rich heteroareness uch as pyrroles, indoles,f urans, and thiophenes. [4][5][6] The corresponding iridium-, rhodium-, or potassium-tert-butoxide-catalyzed CÀHs ilylation reactions furnish C2-silylated products, [5] whilet he C3-Hs ilylation of electronrich heteroarenes is achieved by employing suitable Brønsted/ Lewis acids or iridium/ruthenium complexes (Scheme 1a). [6] On the other hand, the direct CÀHs ilylation of electron-deficient heteroarenes such as pyridines remainsasubstantial challenge in contemporary organic synthesis. [7] Oestreich andc o-worker have reportedt he Ru-catalyzedC ÀHs ilylation of 2-or 3-substi-
