Titanium-catalysed deoxygenation of benzylic alcohols and lignin model compounds

We report a catalytic system for direct deoxygenation of benzylic alcohols by using non-precious precatalyst Cp2TiCl2 and 2-MeTHF as solvent. Mechanistic studies showed that the used silane Me(EtO)(2)SiH acts both as H-donor and regenerating agent of the active catalytic species. This method tolerates a wide variety of functional and protecting groups and enables sequential deoxygenation-dehalogenation and deoxygenation-hydrogenation reactions. The procedure was successfully applied in the exhaustive reduction of lignin model substrates.

Automated summary

We present a catalytic system using non-precious precatalyst Cp2TiCl2 and 2-MeTHF as solvent for direct deoxygenation of benzylic alcohols. Mechansitic studies demonstrate that the silane Me(EtO)(2)SiH not only acts as a H-donor but also as a regenerating agent for the active catalytic species. This method exhibits broad tolerance to various functional and protecting groups, allowing for sequential deoxygenation-dehalogenation and deoxygenation-hydrogenation reactions. The procedure shows successful application in the exhaustive reduction of lignin model substrates.