Traceless Silicon-Tether Strategy for the Synthesis of a Tetraphenylammonium Salt

A traceless silicon-tether strategy enables the synthesis of tetraphenylammonium (Ph₄N⁺) via intramolecular arylative quaternization. The key cyclization step proceeded in 1.2% yield, a 12-fold improvement over the intermolecular approach (0.1%). Subsequent two-step desilylation furnished the target Ph₄N⁺. DFT calculations suggest β-silicon stabilization in the cyclization transition state, although competing pathways are kinetically favored. This work highlights the potential of intramolecular designs for accessing sterically hindered organic cations.