Eco-Friendly Solvent Free Photodecarbonylation for the Synthesis of Biologically Active Natural ProductsEPA Grant Number: SU833911
Title: Eco-Friendly Solvent Free Photodecarbonylation for the Synthesis of Biologically Active Natural Products
Investigators: Garcia-Garibay, Miguel A. , Family, Farnosh , Kuzmanich, Greg , Shiraki, Saori
Institution: University of California - Los Angeles
EPA Project Officer: Nolt-Helms, Cynthia
Project Period: August 15, 2008 through August 14, 2009
Project Amount: $10,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2008) RFA Text | Recipients Lists
Research Category: Nanotechnology , P3 Challenge Area - Materials & Chemicals , Pollution Prevention/Sustainable Development , P3 Awards , Sustainability
Complex natural products pose challenges to sustainability because complex molecules often require chemical auxillaries or vast quantities of solvents in their syntheses and purification before they can be used as medicines. The difficulty in the syntheses of such compounds and the waste associated with their synthesis is evident by the fact that in 2005, pharmaceuticals and medicines produced 500 million tons of toxic waste. A significant obstacle in the synthesis of many natural products is the formation of adjacent quaternary carbon centers, sterically hindered carbon atoms with four different substituents.
Our project to the address this challenge is a green chemistry methodology for synthesizing the molecular skeleton containing the adjacent quaternary centers using sunlight. Our approach will be to synthesize a ketone with quaternary carbon centers at the two alpha positions and then photodecarbonylate in the solid state to remove the ketone and form the bond between the two adjacent quaternary centers. By taking advantage of the chemical information trapped in a crystal lattice, solid state photodecarbonylation does not require any chemical auxiliaries, protection/deprotection, or purification since only one product is formed, thereby eliminating the use of toxic solvents and creation of unused byproducts. Since ketones are generally photo-excited in the UV region of the spectrum, ambient sunlight is sufficient to excite the molecule and therefore photodecarbonylate. The product of the photodecarbonylation will be a molecule with the adjacent quaternary centers. A group of hexahydropyrroloindole alkaloids can be synthesized from this decarbonylated molecule in a few steps.
Through our partnership with Merck, we will explore ways to harvest the sun’s ultraviolet radiation to take this reaction from the academic laboratory to the industry where it will be used to make many valuable medicines available to people who need them. Additionally, we plan bringing the fundamental concepts of green chemistry as they apply to industry to our graduate school curriculum by inviting a speaker from Merck to interact with graduate students.