1 research outputs found
Mechanochemical Oxidation and Cleavage of Lignin β‑O‑4 Model Compounds and Lignin
A mechanochemical
oxidation and cleavage reaction in lignin β-O-4
model compounds and lignin catalyzed by HO–TEMPO/KBr/Oxone
(TEMPO is 2,2,6,6-tetramethyl-1-piperidinyloxy) has been developed
under milling conditions. The studies on nonphenolic lignin β-O-4
model compounds led to selective oxidations of the benzylic hydroxyl
groups. Subjecting phenolic lignin model compounds to the oxidative
conditions in a ball mill initiated aryl–C<sub>α</sub> bond cleavage reactions leading to the formation of the corresponding
quinones and phenol derivatives. Transferring the mechanochemical
protocol to lignin resulted in the simultaneous oxidation and cleavage
of bonds with varied selectivity for monomeric products. Finally,
a scale-up approach of the oxidative procedure by using vibrating
disc mill technology enabled the mechanochemical protocol to be applied
in gram-scale batch reactions under reduced milling time, while affording
a similar extent of oxidation