Facile reaction of bis(tri-n-butyltin) oxide with silica gel

Bis(tri-n-butyltin) oxide quickly reacts with chromatographic silica gel even when a solution of this oxide is filtered through silica gel, which results in stannylation of a fraction of the surface hydroxyl groups of silica gel to give n-Bu₃SnOSi° moieties. The calculated surface density of these moieties, 0.85 Sn groups per nm², corresponds to complete coverage of silica gel surface with n-Bu groups.