With this renewal award the Organic and Macromolecular Chemistry Program supports the work of Dr. Kevin P. Gable of the Department of Chemistry at Oregon State University in Corvallis, Oregon. The research will extend investigations of diolate cycloreversion to study the mechanism of a new epoxide deoxygenation, to determine whether the epoxide undergoes synchronous or asynchronous bond cleavage. A new exploration of useful applications of rhenium-mediated O-atom transfer will be initiated.
Selective transfer of oxygen into organic molecules is a large and important class of organic reactions. One approach is to cleave O2 to form reactive M=O units from a low-valent transition metal complex. Reaction of olefins could then give epoxide or diolate complexes in which one or two new C-O bonds are formed, respectively. Much of the work done here, involving the cycloreversion of oxorhenium(V) diolate complexes, involves the microscopic reverse. Oxygen atom transfer to phosphorus(III) is more thermodynamically favorable than transfer to carbon. Tailoring the steric properties of the ligand in LReO3 should make it possible to separate racemic mixtures of chiral phosphines by selective oxidation of one of the enantiomers. An attractive feature of investment in the project is that the PI includes a large number of undergraduates in his research.