Catalytic Conversions in Water. Part 23: Steric Effects and Increased Substrate Scope in the Palladium-Neocuproine Catalyzed Aerobic Oxidation of Alcohols in Aqueous Solvents
The steric influence of substituents on the 2-and 9-positions of phenanthroline in the (2,9-R2-1,10-phenanthroline)palladium(II)- catalyzed aerobic oxidation of 2-hexanol was investigated by means of high throughput experimentation. (Neocuproine)Pd-(OAc)2 (R=CH 3) was found to be a highly active catalyst for alcohol oxidation in 1:1 water/DMSO mixtures. The catalyst is unique in that it tolerates water, polar co-solvents and a wide variety of functional groups in the alcohol. Turn-over frequencies of > 1500 h-1 were achieved and a series of alcohols was oxidised with 0.1 to 0.5 mol % of catalyst.
Ten Brink, Gerd-Jan,Arends, Isabel W. C. E.,Hoogenraad, Marcel,Verspui, Goeran,Sheldon, Roger A.
p. 1341 - 1352
(2007/10/03)
Catalytic Conversions in Water. Part 21: Mechanistic Investigations on the Palladium-Catalysed Aerobic Oxidation of Alcohols in Water
Water-soluble complexes of palladium(II) with phenanthroline-derivatives are stable, recyclable catalysts for the selective aerobic oxidation of a wide range of alcohols to aldehydes, ketones, and carboxylic acids in a biphasic liquid-liquid system. The active catalyst is a dihydroxy-bridged palladium dimer. Kinetics of the reaction, ligand and anion effects are discussed.
Ten Brink, Gerd-Jan,Arends, Isabel W. C. E.,Sheldon, Roger A.
p. 355 - 369
(2007/10/03)
ORGANOSELENIUM-MEDIATED REDUCTION OF α,β-EPOXY KETONES TO β-HYDROXY KETONES: A NEW ACCESS TO INTER- AND INTRAMOLECULAR ALDOLS
The organoselenium-mediated reduction of α,β-epoxy ketones has been demonstrated to be a promising entry to a variety of cyclic and acyclic aldols.