A University of Wisconsin-Madison professor of chemistry has received a grant to develop “green” techniques to produce compounds for the pharmaceutical industry. Shannon Stahl says his particular challenge is to find ways to use air as an environmentally benign oxidant for pharmaceutical synthesis, by developing catalysts composed of earth-abundant metal catalysts, such as copper, iron and vanadium.
“Nearly all organic compounds will react with air, but usually they just undergo combustion to form carbon dioxide,” he says, so chemical manufacturers need to use catalysts to control chemical reactions between organic molecules and oxygen gas. Stahl's focus will be the oxidation of alcohols to carbonyl compounds. This chemical reaction is a commonly used in the pharmaceutical industry, but it often requires the use of toxic or wasteful reagents.
Green chemistry has received a lot of attention in recent years. “Ten years ago, I was pretty skeptical of the hype surrounding 'green chemistry,' but the pharmaceutical industry has done a good job in recent years of highlighting some of the fundamental scientific breakthroughs needed to make a real difference in this area. I give them a lot of credit for directing the attention away from hype and toward fundamental science.”
Stahl's green chemistry proposal received $150,000 from the Pharmaceutical Roundtable of the American Chemical Society, which was created to focus attention on the key issues of industrial concern related to green chemistry.
Since starting his career at UW-Madison in 1999, Stahl and his group have developed expertise in “aerobic oxidation” chemistry. The key to success in this area, Stahl says, “is to identify catalysts that allow oxygen and organic molecules to be manipulated in ways that avoid combustion and enable the formation of useful products.”
Stahl notes that many of the successful catalysts that have been identified previously consist of expensive and toxic precious metals like palladium and platinum. “In this project, we're targeting catalysts composed of common elements like copper or iron that are less toxic and in abundant supply.”