Selective Hydrogenolysis of C–O Bonds Using the Interaction of the Catalyst Surface and OH Groups

Vanadium Pyridonate Catalysts: Isolation of Intermediates in the Reductive Coupling of Alcohols

The reductive coupling of alcohols using vanadium pyridonate catalysts is reported. This attractive approach for C(sp³)-C(sp³) bond formation uses an oxophilic, earth-abundant metal for a catalytic deoxygenation reaction. Several pyridonate complexes of vanadium were synthesized, giving insight into the coordination chemistry of this understudied class of compounds. Isolated intermediates provide experimental mechanistic evidence that complements reported computational mechanistic proposals for the reductive coupling of alcohols. In contrast to previous mononuclear vanadium(V)/vanadium(III)/vanadium(IV) cycles, this pyridonate catalyst system is proposed to proceed by a vanadium(III)/vanadium(IV) cycle involving bimetallic intermediates.

Reduction of sugar derivatives to valuable chemicals: utilization of asymmetric carbons

Recent progress on non-furfural routes from sugar derivatives to valuable chemicals including chiral chemicals was reviewed.

Hydrogenolysis of C-O Chemical Bonds of Broad Scope Mediated by a New Spherical Sol-Gel Catalyst

The new spherical sol-gel hybrid material SiliaCat Pd0 selectively mediates the hydrogenolysis of aromatic alcohols, aldehydes, and ketones by using an ultralow catalytic amount (0.1 mol % Pd) under mild reaction conditions. The broad reaction scope as well as the catalyst's superior activity and pronounced stability open the route to green and convenient reductive deoxygenation processes of primary synthetic relevance in chemical research as well as in the fine chemical and petrochemical industries.

Selective hydrogenolysis of glycerol to 1,3-propanediol over egg-shell type Ir–ReOx catalysts

The egg-shell catalysts could promote the conversion of glycerol while maintaining an acceptable pressure gradient.

Effective hydrodeoxygenation of dibenzofuran by a bimetallic catalyst in water

Hydrodeoxygenation of dibenzofuran by Ni/Pt bimetallic catalyst was achieved with 99% total conversion and 88% of selectivity of cyclohexylbenzene.

Hydrogenation of dicarboxylic acids to diols over Re–Pd catalysts

Ex situ liquid-phase reduced Re–Pd/SiO₂ (Re/Pd = 8) showed good performance in the hydrogenation of dicarboxylic acids to diols.

Catalytic total hydrodeoxygenation of biomass-derived polyfunctionalized substrates to alkanes

The total hydrodeoxygenation of carbohydrate-derived molecules to alkanes, a key reaction in the production of biofuel, was reviewed from the aspect of catalysis. Noble metals (or Ni) and acid are the main components of the catalysts, and group 6 or 7 metals such as Re are sometimes added as modifiers of the noble metal. The main reaction route is acid-catalyzed dehydration plus metal-catalyzed hydrogenation, and in some systems metal-catalyzed direct CO dissociation is involved. The appropriate active metal, acid strength, and reaction conditions depend strongly on the reactivity of the substrate. Reactions that use Pt or Pd catalysts supported on Nb-based acids or relatively weak acids are suitable for furanic substrates. Carbohydrates themselves and sugar alcohols undergo CC dissociation easily. The systems that use metal-catalyzed direct CO dissociations can give a higher yield of the corresponding alkane from carbohydrates and sugar alcohols.