Diastereoselective synthesis of pinacols from aromatic aldehydes using the system pentacarbonyliron-hexamethylphosphoric triamide. Dual reactivity of pentafluorobenzaldehyde

The system Fe(CO)5-HMPA effectively promotes diastereoselective reductive dimerization of aromatic aldehydes to the corresponding pinacols having preferentially or exclusively dl configuration. In the reaction with pentafluorobenzaldehyde, the product structure strongly depends on the presence of traces of moisture in the reaction system.