Date of Degree
PhD (Doctor of Philosophy)
Ned B. Bowden
The turnovers of a gold(III) chloride catalyst were increased by 3,300% with the addition of several equivalents of (2,2,6,6-tretramethyl-piperidin-1-yl)oxy and catalytic amounts of copper(II) chloride. A three component coupling reaction between piperidine, phenylacetylene, and benzaldehyde yielded a propargylamine in quantitative conversions and isolated yields when gold(III) chloride was added in catalytic amounts, but the gold catalyst decomposed and had little to no reactivity when a second set of piperidine, phenylacetylene, and benzaldehyde were added after the reaction was complete. The addition of (2,2,6,6-tretramethyl-piperidin-1-yl)oxy and copper(II) chloride to reactions with gold(III) chloride maintained the catalytic activity of the gold for up to 33 cycles. This result demonstrates a new way to greatly increase the turnovers of a gold(III) chloride catalyst with the addition of inexpensive, commercially available reagents.
The synthesis and some of the physical properties of the first poly(disulfidediamines) are reported. These polymers were synthesized in high yields and with conversions up to >98% by reactions between secondary diamines and a new disulfide monomer. The disulfide monomer was synthesized in two steps without the need for column chromatography. The polymerizations were robust and completed at room temperature, under ambient atmospheric conditions, and in solvents that were used as purchased. These polymers were stable, but they rapidly decomposed under acidic, aqueous conditions to release hydrogen sulfide. A method for quantifying the hydrogen sulfide released was also developed.
Copyright 2012 Tyler Anton Graf
Graf, Tyler A.. "Poly(disulfidediamines) : new biodegradable polymers." dissertation, University of Iowa, 2012.