A photocatalytic acid- and base-free Meerwein-Ponndorf-Verley-type reduction using a [Ru(bpy)3]2+/viologen couple.
A photocatalytic system to effect the Meerwein-Ponndorf-Verley reduction of carbonylic compounds to alcohols has been developed. The system comprises [Ru(bpy)3]2+ as a photosensitizer, triethanolamine as a sacrificial electron donor, viologen as an electron acceptor, and the carbonyl compound and iPrOH as Meerwein-Ponndorf-Verley reagents. The photocatalytic reaction can be performed in neat iPrOH or in 1-butyl-3-methylimidazolium ionic liquid. Mass spectrometric detection of the viologen hydride derivative VH+ confirms that this species is the reducing agent responsible for the carbonyl compound reduction. The reaction intermediates involved in the photocatalytic system have also been characterized by laser flash photolysis.
Herance
Jose Raul
JR
Instituto de Tecnología Química, Universidad Politécnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain.
Ferrer
Belén
B
Bourdelande
Jose Luis
JL
Marquet
Jordi
J
Garcia
Hermenegildo
H