Utilization of Carbon Dioxide

With the depletion of the petroleum feedstock, it has become necessary to seek new carbon sources. Carbon Dioxide was identified in the last decades as one potential safe and renewable C1 feedstock. Part of our research aims at the utilization of carbon dioxide for the synthesis of various functionalities such as acid, esters, carbonate and carbamate.

Lignans are phyto-estrogens molecules naturally present in plants. They have demonstrated attractive properties not only as anti-cancer or anti-viral agents but also have proven to be effective for hormonal balance. In an effort to “green” the synthesis of those pharmaceutical agents, we are investigating new multi-components coupling and cyclo-addition strategies.

New methodologies for the synthesis of Podophyllotoxin, Retrochinensin, Daurinol and are currently under investigation.

A portion of the research program is rooted in "traditional" organic synthesis and methodology. The GCI-Pharmaceutical Roundtable recently highlighted the Mitsunobu Reaction as a high priority reaction for development. We have previously demonstrated that a variation of the Mitsunobu proceeds in good yield under aqueous conditions. In addition to further developing the Aqueous Mitsunobu we will also be looking at ways to make the Mitsunobu catalytic, as well, using benign stoichiometric reagents such as O2, H2O2 and N2.

We are looking at greener methods and applications of diazonium salt chemistry by utilization of safer and less hazardous reagents. We are using computational modeling to explore the mechanism of the Rappe Rearrangment of 1,3-dihaloketones to the contrathermodynamic cis-crotonic acids, a preparative method that proceeds in water; the hope is that it will shed light on other reactions in water.

Design of "green" polymer additives:

Diethyl hexyl phthalate (DEHP), a common plasticizer for poly(vinyl chloride) (PVC), impacts development of the human male reproductive system. In some applications, DEHP exceeds PVC by mass in the plastic compound. Human exposure to DEHP and environmental releases are thus potentially high. We are working to develop non-toxic, biodegradable plasticizers based on derivatives of biomass platform chemicals. This is part of a broader "green" polymer project that aims to expand the use of environmentally benign polymers including chitin, poly(lactic acid), and poly(hydroxyalkanoates).

Polymer-surfactant interactions:

Collaboration with Prof. Chinedum Osuji in the Chem. Eng. dept. Osuji's group investigates the binding of surfactants to specific sites on a polymer backbone. Understanding the physics of these interactions is a first step in the development of stimuli-responsive materials. Non-covalent chemistry is of great interest to Green Chemists because of the potential reductions in energy cost, solvent use, and waste generation. We are working with the Osuji group to "green" the surfactant structures and synthetic pathways.

Next generation biofuels:

The Anastas group is partnering with the African Power Initiative to promote biofuels which are not derived from food crops and do not require fertile land. The API is growing jatropha, castor, and candlenut on marginal land in Uganda. We are investigating potential uses for waste materials from the oil recovery and refining processes. The work of Prof. Richard Wool at the University of Delaware suggests that the seed oils may find other useful applications in Africa besides fuels.