Directed metalation of aromatic aldimines with lithium 2,2,6,6-tetramethylpiperidide

A simple method for the directed lithiation of N-cyclohexyl aromatic aldimines with lithium 2,2,6,6-tetramethylpiperidide (LTMP) in THF solution is discussed. The results show that functionalization of the lithiated aldimines involved several electrophiles. Subsequent acid hydrolysis of the product resulted in substituted aromatic aldehydes with good to excellent yield. Facile lithiation of aldemines was described as a useful solution to the problem of directed metalation of aromatic aldehyde derivatives.