Reductive lithiation of 1,3-dimethyl-2-arylimidazolidines

Naphthalene catalyzed lithiation of 1,3-dimethyl-2-phenylimidazolidine led to cleavage of the benzylic carbon–nitrogen bond, with formation of an intermediate dianion. Under similar conditions, 1,3-dimethyl-2-(4-chlorophenyl)imidazolidine underwent regioselective cleavage of the aromatic carbon–chlorine bond, leading to a 4-formylphenyllithium equivalent, whilst 1,3-dimethyl-2-(4-methoxymethylphenyl)imidazolidine underwent regioselective cleavage of the benzylic carbon–oxygen bond, leading to a 4-formylbenzyllithium equivalent.