Effects of the reactants concentration in the butadiene telomerization with d-xylose and parallel influence of triethylamine as additive

The efficiency and the selectivity of the palladium-catalyzed telomerization of butadiene with d-xylose in DMF were strongly dependent on the presence of triethylamine as additive for low sugar concentrations. The amine influence, which would mainly be due to its both basic and coordinating properties, disappeared at high sugar concentrations. The selectivity towards the monografting could reach 98% at 50% sugar conversion (with 82% of linear isomers) and could be maintained at 71% at 96% conversion (with a similar ratio of linear isomers).

Graphical abstractBetter conversions and selectivities with NEt3 at low xylose concentrations.No more influence of NEt3 at high xylose and butadiene concentrations. Figure optionsDownload full-size imageDownload as PowerPoint slide