Lignocellulose presents a potential future carbon source for production of fuels and chemicals. The high density of functional groups opens numerous possibilities for tailored chemical transformations to novel target molecules. With regard to catalysis, however, this over-functionalization makes high demands on catalyst and process development. Today's refineries are based on gas phase processes at high temperatures introducing functionality in non-polar feedstocks. In contrast, transformations based on lignocellulose require liquid phase processes in polar solvents at rather low temperatures.