Iron-Catalyzed Reductive C(aryl)-Si Cross-Coupling of Diaryl Ethers with Chlorosilanes

The reductive cross-coupling between C(aryl)-O and Si-Cl bonds is of much importance as a valuable strategy for the construction of C(aryl)-Si bonds but has remained a great challenge. Herein, we report a reductive cross-coupling of diaryl ethers and chlorosilanes via strong electrophilic C(aryl)-O and Si-Cl bonds cleavage by iron catalysis, which constitutes an efficient protocol for the synthesis of a range of functionalized arylsilanes. The combination of low cost FeCl2 as the precatalyst and iPrMgCl as the reductant shows high activity in the successive cleavage of unactivated C(aryl)-O bonds of diaryl ethers and strong electrophilic Si-Cl bonds of chlorosilanes, allowing their cross-coupling in a reductive fashion. The low-valent iron species generated in situ by reduction of FeCl2 with iPrMgCl was proposed, which prefers to initially cleavage the C(aryl)-O bond of diaryl ethers with the chelation help of an o-amide auxiliary.