Organic reactions on silica surface: Synthetic applications

The literature is analyzed on organic reactions proceeding in the presence of silica (mainly in its unmodified form) and the uses for synthetic tasks. Oxidation (including dry ozonation), reduction, alkylation, acylation, halogenation, elimination, hydrolysis, dehydration, intermolecular cycloaddition and other cyclization reactions, three member-cycle openings, peroxide decomposition, some photochemical reactions, etc, are considered. In these processes, silica surface can act as a catalyst, solid reaction medium and/or matrix influencing the stereospecificity; however detailed information on the reaction mechanisms is not available so far.