c3bio.org will be decommissioned on Monday, December 22, 2014. Please retrieve any important data before that date as the site will no longer be accessible. Thank you for your support.

Support

Support Options

Submit a Support Ticket

 
You are here: HomeGroupsC3Bio Entire GroupResourcesPublicationsCatalytic oxidation of para-substituted phenols with cobalt–Schiff base complexes/O2—selective conversion of syringyl and guaiacyl lignin models to benzoquinonesAbout

Catalytic oxidation of para-substituted phenols with cobalt–Schiff base complexes/O2—selective conversion of syringyl and guaiacyl lignin models to benzoquinones

By Diana Cedeno1, Joseph J Bozell1

1. University of Tennessee

You must be logged in and a member of one of the following groups to access the full resource: c3bioteam

See also

No results found.

Published on

Abstract

Models of guaiacyl (G) and syringyl (S) subunits in lignin have been catalytically oxidized to their corresponding p-quinones in the presence of molecular oxygen. The oxidation of syringyl-like phenols readily occurred with 5-coordinate cobalt catalysts on which one of the ligands is a monodentate pyridine or imidazole base that coordinates axially to the metal. Formation of p-quinones with this system depends on the coordination of the axial base to the metal as influenced by its pKa and its size. The yield of p-quinones from guaiacyl models was markedly improved by the addition of a sterically hindered aliphatic nitrogen base that does not coordinate to the catalyst. A mechanism involving deprotonation of the phenol substrate by the bulky base is proposed.
2012 Elsevier Ltd. All rights reserved.

Tags