Catechol‐Mediated Redox‐Neutral One‐pot Transformation of SiO2 into SiPh4

A redox-neutral, direct transformation of silica gel (SiO₂) to SiPh₄ is developed by a one-pot reaction in THF or Bu₂O. Catechol mediates the depolymerization of silica and provides a suitable electrophile for the nucleophilic attack of phenyl lithium. It represents the first one-pot formation of a Si−C bond starting from silica.

Abstract

Organosilanes range among the most important products in chemical industries. Unfortunately, their bulk production starting from silicon oxides has a substantial ecological footprint due to the immense energy consumption and the numerous hazardous by-products imposed by the redox cycling between Si(0) and Si(IV). Herein, we report the first redox-neutral, one-pot silicon−carbon bond formation starting from silica gel by combining catechol-mediated SiO₂ depolymerization and nucleophilic substitution of the tris(catecholato)silicate dianion intermediates. Screening and optimization of the individual steps enables a 76 % yield of SiPh₄ on a preparative scale. Non-rationalizable effects of solvents, nucleophiles, and countercations are identified, rendering suitable for statistical optimization approaches such as “design-of-experiments” in future studies. The general success of such process encourages the search for more energy- and waste-effective organosilane production.

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