Chemistry Department Seminar Thomas Baker University of Ottawa "Wood Eye! Selective Aerobic Oxidation of C-C Bonds in Lignin Models using Base Metal Complexes: A Comparison of Oxovanadium and Copper Catalysts"CANCELLED! Rescheduled for Sepetember!
- 4/4/2014 |
3:00 PM – 4:00 PM
Location: Druckenmiller Hall, Room 020
Event Type: Seminar
Selective aerobic oxidation of lignin is being explored with a view to obtaining valuable aromatic chemicals.1 While many C-O bonds can be cleaved by heat or acid treatments to afford aromatic products such as vanillin, selective oxidative cleavage of C-C bonds may afford complementary aldehyde and acid products that could be converted subsequently into value-added aromatic chemicals. In previous work we showed that pyridine enables a novel 2 e- alcohol oxidation mechanism using oxovanadium complex catalysts and air.2 This led to different selectivity in C-C bond cleavage reactions of diols and a-hydroxyether lignin models vs. less basic solvents such as acetonitrile or DMSO.3 In contrast, use of simple copper halide salts in pyridine4 bypasses the C-H oxidation pathway in favour of direct C-C bond cleavage.5 Reactivity of the copper and vanadium catalysts in the oxidation of more complex b-O-4 lignin model compounds will be compared and the differences in selectivity discussed.