In sustainable chemistry, the switch towards biomass-based resources requires to develop new catalysts for new reactions. Although simulation could be an excellent tool for the design of novel catalysts, the large size of the reaction network and the solvated conditions render brute force first principle calculations hopeless. In this project, we propose a novel multi-level and multi-scale approach to solve this issue and explore the complex pathways of the catalytic transformation of sugar molecules extracted from biomass using bifunctional catalysts. The complete reaction pathway, with hundreds of reactions, will first be mapped with a simple, approximate but very fast force-field approach. Kinetic simulation on that reaction array will dictate the few important elementary steps that need to be accurately calculated. This high level will be performed with state of the art hybrid multi-scale free energy barrier simulations, including full treatment of the solvent.