DeVasher Laboratory
Research
Global concern for the environment has
rapidly grown in the past three decades in response to increasing
problems with waste treatment, air and water pollution, and other key
issues addressed by the United States Environmental Protection
Agency. The key to solving issues of human health and
environmental protection lies in the hands of environmentally friendly
technologies. Green chemistry involves the development of new
methods and technologies that reduce or eliminate the use of chemicals
hazardous to human health and the environment. Our group promotes
atom economy, implements the use of safer solvents and auxiliaries, and
develops less hazardous chemical syntheses through aqueous-phase
catalysis. Palladium catalysts derived from sterically demanding,
water-soluble phosphine ligands couple aryl bromides in both neat water
and in a 1:1 toluene:water biphasic system. Couplings in neat
water provide an environmentally friendly synthesis for carboxylic acid
derivatives such as the FDA approved NSAID drug diflunisal.
Student researchers will be using GC/MS, 1H
NMR and 13C NMR instrumentation to determine
product identity, purity and yield for newly developed synthetic
methodologies. We are also interested in determining the exact
catalytic mechanism in various solvent systems. The general
cross-coupling mechanism is believed to be homogeneous, but certain
data suggest that the mechanism for the cross-coupling reaction could
be colloidal in aqueous-phase solvent systems. Our group will try
to elucidate the mechanism of the aqueous-phase reaction by
investigating the chemical kinetics under conditions that alter the
surface area of the active catalyst species.
