Phosphates: New generation of liquid-phase heterogeneous catalysts in organic chemistry

This two part review looks at the uses of phosphate based heterogeneous catalysts for a range of synthetic organic reactions. Many different phosphates are known and have been tested as catalysts in a wide range of reaction types, either as catalysts, or in combination with other species such as zinc chloride or KF. The first section deals with the wide variety of phosphates which have been utilized in organic chemistry, while the second focuses more tightly on catalysts derived from naturally occurring phosphates. In all cases, efficient reactions can be achieved and in many reactions, significant solvent effects have been noted. Of benefit is the fact that relatively benign solvents such as lower alcohols and water are often the most effective.