Electroreductive Coupling of Aldehydes and Subsequent Pinacol Rearrangement for 1,2‐Disubstituted Ethanones.

An electrochemical method for the generation of 1,2‐diols through the reductive coupling of aldehydes has been developed, and the 1,2‐diols were used directly without separation for the pinacol rearrangement process. The electro‐organic strategy had mild reaction conditions and avoided the use of reductants. The pinacol rearrangement was controllable to access to the hydride‐migrated product 1,2‐disubstituted. The key factor in selectivity was the use of macrocyclic compound cucurbit[7]uril, which plays a key role in the interaction with aromatic ring of 1,2‐diol. On the basis of experimental results, the mechanism, include the electroreductive coupling and pinacol rearrangement process, was illustrated. [ABSTRACT FROM AUTHOR]