Latent Carbene in Diaminomethylation of Benzenes: Mechanism and Practical Application.

Silylformamidine exists in equilibrium with its carbenic form due to an easy migration of the silyl group. The reaction of with variously substituted fluorobenzenes proceeds as an insertion of the nucleophilic carbene into the most acidic C-H bond upon mixing the reagents and does not require any catalyst. According to DFT calculations, the classical interpretation of the insertion reaction proceeding via a three-membered transition state structure requires high activation energy.