Current Research Interests of Kurt Birdwhistell’s group

We are applying the principles of Green Chemistry to design new “Environmentally Benign” synthetic pathways to inorganic and organic molecules. Green chemistry involves the application of a set of principles to reduce or eliminate hazardous materials in the synthesis of chemical products. The ultimate goal of “Green Chemistry” is a sustainable civilization.
Our current projects in “Green Chemistry” involve the application of four synthetic strategies:

1. Reducing the energy requirements of reactions by applying Microwave Assisted Synthesis (MAS).
2. Eliminating organic solvents in synthetic reactions by using an environmentally benign solvent such as water.
3. Replacing hazardous mineral acids such as sulfuric or phosphoric acid with safer solid acid alternatives.
4. Designing new water-soluble catalysts for the replacement of catalysts normally used in organic solvents.

1. Biphasic Phase Transfer Catalysis Using Microwave Assisted Synthesis.

The mechanism for the phase transfer catalyst mechanism is shown to the left. Using a biphasic system reduces the amount of organic solvent used while accelerating the reaction rate. One solvent, water, is microwave active while the second solvent, toluene, is not. This allows us to quickly heat the water via microwaves and the product gets deposited in the organic phase(toluene). In this case we are using phase transfer catalysis to produce Group VI metal carbonyl complexes with chelating and nonchelating ligands from the parent metal carbonyl complex (M(CO)₆).

Presentation On Biphasic Phase Transfer Catalysis from Green Chemistry and Engineering Conference June 2009



2. Application of Green Chemistry principles to the synthesis of Acetylferrocene

Below is an example of the application of green chemistry principles to the synthesis of an important organometallic compound, acetylferrocene.

1. In the example (to the left) we were able to replace the mineral acid, phosphoric acid, with the safer polymeric acid Amberlyst 15 (a polymeric sulfonic acid). This replacement allows us to significantly reduce the waste stream created by neutralization of the mineral acid.
2. This reaction is an example of a solventless reaction where the reactant acetic anhydride acts as the solvent; thus reducing solvent usage and waste.
3. Using microwave instead of thermal heating prevents the formation of the tarry byproduct which is commonly observed when phosphoric acid is utilized. The microwave energy does not increase the reaction rate in this example, but results in a cleaner, more selective product formation.

Presentation at ACS meeting Spring 2008 on Ferrocene Acylation using Amberlyst

The above material is based upon work supported by the National Science Foundation under Grant No. 0535957. Any opinions, findings and conclusions or recomendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).