Chemoselective Metal-Free Aerobic Alcohol Oxidation in Lignin

Chemoselective metal-free aerobic alcohol oxidation in lignin.

An efficient organocatalytic method for chemoselective aerobic oxidation of secondary benzylic alcohols within lignin model compounds has been identified. Extension to selective oxidation in natural lignins has also been demonstrated. The optimal catalyst system consists of 4-acetamido-TEMPO (5 mol %; TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) in combination with HNO3 and HCl (10 mol % each)...

Chemoselective organocatalytic aerobic oxidation of primary amines to secondary imines.

Biomimetic aerobic oxidation of primary benzylic amines has been achieved by using a quinone catalyst. Excellent selectivity is observed for primary, unbranched benzylic amines relative to secondary/tertiary amines, branched benzylic amines, and aliphatic amines. The exquisite selectivity for benzylic amines enables oxidative self-sorting within dynamic mixtures of amines and imines to afford h...

An aerobic, organocatalytic, and chemoselective method for Baeyer-Villiger oxidation.

Free radical reaction promoted by ionic liquid: a route for metal-free oxidation depolymerization of lignin model compound and lignin.

Ionic liquid 1-benzyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BnMIm][NTf2]) can promote the generation of the ˙OOH free radical and thereby efficiently transformed the β-O-4 lignin model compound 2-phenoxyacetophenone into benzoic acid and phenol using O2 as the oxidant. Furthermore, the IL-based metal-free catalytic system can also depolymerize other lignin model compounds and ...

Highly chemoselective metal-free reduction of tertiary amides.

This communication describes the chemoselective metal-free reduction of tertiary amides to the corresponding amines. Hantzsch ester is used as a mild reducing agent for the reduction of trifluoromethanesulfonic anhydride activated amides providing the tertiary amines with high functional group tolerance.