Reductive Coupling of Aromatic Aldehydes Promoted by an Aqueous TiCl₃/tBuOOH System in Alcoholic Cosolvents.

Abstract

The reaction provides a fast, mild, and chemoselective method for the reductive pinacolization of aromatic aldehydes to give the corresponding 1,2-diols as 1:1 mixtures of diastereomers. The active reducing agent is found to be the α-hydroxyalkyl radical generated from the alcoholic cosolvent iPrOH or EtOH by reaction with the tBuO radical. -(CLERICI, A.; GRECO, C.; PANZERI, W.; PASTORI, N.; PUNTA, C.; PORTA*, O.; Eur.