Development of synthetic methods for C-O and C-C bond formations via transition metal catalysis

Recent developments in transition metal catalysis have had a tremendous impact on the science of synthesis. They have allowed conceptually new approaches towards previously unaddressed synthetic problems and have challenged synthetic chemists to imagine unrecognized modes of chemical transformations. The presented thesis aims to exemplify both aspects of these recent developments in transition metal catalysis.; The first three chapters deal with the problem of C-O bond formation. Despite its importance, the construction of the C-O bond has not been a trivial synthetic problem. Recognition of this challenge led to the development of a palladium catalyzed allylic etherification method for stereoselective C-O bond formations. Utilizing the zinc(II) ion as the countercation of an alkoxide nucleophile allowed the development of a reliable method to construct alpha,alpha' stereogenic ether linkages for the first time. Extension of this chemistry into the carbohydrate area demonstrated the first report of a reagent controlled stereoselective glycosylation of glycals.; The latter three chapters deal with discovering new modes of C-C bond formation with utilization of metal vinylidene catalysis. Metal vinylidenes are organometallic intermediates with unique structures and reactivities. Only recently has the synthetic community started to examine their potential as useful synthetic intermediates. Taking part in these efforts, the dual reactive nature of the metal vinylidene was illustrated in the context of rhodium vinylidene catalyzed enyne cycloisomerization via [2+2] cycloaddition and a nucleophile-triggered cycloisomerization of N-propargyl enamine derivatives.