New Methods for the Deoxygenation of 1,2-diols and Epoxides.

摘要

Chapter 1 : Introduction. Our chemical industry is currently capable of converting fossil fuel feedstocks (unsaturated hydrocarbons) into useful polymers and chemicals. Replacing those feedstocks with renewable sources is an important goal for sustainability. Our research focuses on the defunctionalization of heavily oxygenated biomass materials so they can be used in the chemical industry's current factories. Of particular interest are three and four carbon monomers which would be obtained from the defunctionalization of the simple alditols glycerol and erythritol.;Chapter 2 : Formic Acid-Mediated Didehydroxylation of Vicinal Diols: Reaction Development and Mechanistic Studies. We developed a simple formic acid-mediated didehydroxylation of diols. Our substrate scope was limited to simple polyols. Isotope labeling studies suggested the intermediacy of a carbocation as well as an orthoformate ester. Attempts at isolating the carbocation intermediate were unsuccessful.;Chapter 3 : CO2 Reduction -- In situ Formation of Formic Acid with Concomitant Didehydroxylation of Vicinal Diols. We successfully reduced carbon dioxide with a heterogeneous rhodium catalyst to form a mixture of formic acid and amine. Attempts at didehydroxylation using the synthesized mixture were successful, though low yielding. Concomitant reduction of carbon dioxide and didehydroxylation was not achieved.;Chapter 4 : Rhenium-Catalyzed Deoxygenation of Diols and Epoxides. Many oxo-rhenium catalysts were synthesized and used for the deoxygenation of diols and epoxides. We were unable to obtain conclusive spectroscopic data of the reaction's progress, limiting our ability to propose a mechanism.