<i>In-Situ</i>-Generated Active Hf-hydride in Zeolites for the Tandem N-Alkylation of Amines with Benzyl Alcohol

In this work, we have studied the catalytic activity of different silicates (MFI, MCM-41, and Beta) containing Lewis acid sites (including Sn, Ti, Zr, Hf) for tandem N-alkylation reaction aniline with benzyl alcohol. The Hf- Zr-Beta were most active catalysts transformation, showing in both cases selectivities toward corresponding N-benzylaniline higher than 97%. FTIR DFT analyses confirm that Hf-Beta catalyst process are open where one four Hf–O bonds is hydrolyzed. Moreover, amount these species could be notoriously increased previous thermal treatment zeolite Isotopically labeled experiments theoretical mechanistic studies reveal occurs through a hydrogen borrowing pathway, which situ Hf-hydride generated. Finally, was reused several times without any appreciable deactivation detected. This system expanded to variety amines, including aliphatic biomass-derived amines.