Deprotonative C(sp³)/C(sp²)-H (Multi)Silylation of (Hetero)Arenes Mediated by NaTMP

The importance of organosilicon compounds in synthetic and materials chemistry has prompted the search for efficient and broadly applicable routes to these invaluable scaffolds, which often depend on scarce transition metals. In contrast, main group-mediated strategies remain underdeveloped, with those reported generally limited to activated substrates and harsh reaction conditions. Here, a new sodium-mediated protocol for deprotonative C(sp³)/C(sp²)-H silylation of (hetero)arenes is presented, which relies on the power of the strongly basic sodium amide NaTMP (TMP = 2,2,6,6-tetramethylpiperidide) in combination with bulky chlorosilanes. This approach provides direct access to a myriad of silylated aromatic products, including toluene derivatives, non-activated arenes such as benzene and naphthalene, pyridines and electron-rich heterocycles. Mechanistic investigations, combining the isolation of key organometallic intermediates with theoretical calculations, underline the complementarity of NaTMP and the electrophilic chlorosilane, and reveal the steric and coordination effects that govern sodiation and silylation steps. Most notably, this protocol extends beyond conventional monosilylation, including orthogonal multisilylation of distinct C(sp³) and C(sp²)-H bonds, thereby broadening the scope of main group-mediated arene functionalization.