Author Contact: aknight@fit.edu
This experiment highlights both the importance of palladium catalyzed coupling reactions and the need for finding greener solvents. The aqueous-phase coupling of iodobenzene and diethylphosphite is a great example of how a reaction can be made greener with a relatively straight-forward modification. By simply sulfonating triphenyl phosphine, students will be synthesizing a water-solubilizing ligand to use in their coupling reaction.
Pedagogical benefits include introducing students to palladium-catalyzed coupling reactions, aqueous phase chemistry, electrophilic aromatic substitutions, recrystallizations, redox chemistry, liquid-liquid extractions, rotary evaporation, proton and phosphorous NMR, IR spectroscopy and air-free reaction conditions (nitrogen balloons or schlenk lines).
Supplemental information includes experimental procedures, chemical list, and spectroscopic data.
Summary prepared December 2008 by Douglas M. Young at the University of Oregon.
Harper, B. A.; Rainwater, J. C.; Birdwhistell, K.; Knight, D. A. J. Chem. Educ., Print 2002, 79, pp 729-730.