223706-43-2Relevant academic research and scientific papers
Degradation of β-O-4 model lignin species by vanadium Schiff-base catalysts: Influence of catalyst structure and reaction conditions on activity and selectivity
Parker, Heather J.,Chuck, Christopher J.,Woodman, Timothy,Jones, Matthew D.
, p. 40 - 47 (2016/05/10)
In the pursuit of value-added products from the degradation of the abundant aromatic biopolymer lignin, homogeneous catalysis has the potential to provide a mild, selective route to monomeric phenols. Homogeneous vanadium catalysts have previously been shown to effectively cleave dimeric β-O-4 model lignin compounds, with selectivity for C-C or C-O cleavage, or benzylic oxidation, depending on the ligand structure and oxidation state of the metal. In this study, a systematic kinetic investigation was undertaken in order to gain further understanding of the role of ligand structure and reaction conditions on the activity of vanadium Schiff-base catalysts towards a non-phenolic β-O-4 model lignin dimer, and the selectivity of these species towards C-O bond cleavage. Catalytic activity was found to be increased by the addition of bulky, alkyl substituents at the 3′-position of the phenolate ring, whereas electron-withdrawing substituents were found to dramatically reduce activity irrespective of their size. Selective depolymerization of a phenolic β-O-4 dimer was also achieved.
Synthesis of salicylaldehydes bearing bulky substituents in the positions 3 and 5
Kochnev,Oleynik,Oleynik,Ivanchev,Tolstikov
, p. 1125 - 1129 (2008/09/17)
Reaction of 2,4-disubstituted phenols with paraformaldehyde in the presence of SnCl4 and 2,6-lutidine afforded a number of new salicylaldehydes, containing bulky substituents (tert-butyl, 1-phenylethyl, 1-(4-tert- butylphenyl)ethyl, α-cumyl, and trityl) in the positions 3 and 5.
