Date of Award
Doctor of Philosophy
Chapter I describes the synthesis of arylolefins in fair to good yield by the cross-coupling reaction of arylmercurials and vinyl halides catalyzed by 10% ClRh(PPh(,3))(,3). The reaction appears to involve initial oxidative addition of the vinyl halide to the rhodium(I) catalyst to yield a vinyl rhodium(III) species and subsequent arylation by the organomercurial to generate an aryl vinyl rhodium(III) intermediate which reductively eliminates the olefin and regenerates the catalyst;Chapter II details an improved, stereospecific synthesis of vinylmercurials from alkynes using catecholborane, followed by mercuric acetate plus sodium acetate. A vinylmercurial useful in prostaglandin synthesis is prepared using this procedure;Chapter III summarizes our efforts towards the total synthesis of brefeldin-A using the reaction of a vinylpalladium species with cyclopenetene derivatives as a first key step. Even though the reactions lead to the expected product(s), the yields could not be optimized. An alternative approach using the reaction of a vinylcuprate with cyclopentadiene monoepoxide also leads to the expected key intermediate, but the yield again could not be optimized;In Chapter IV, new synthetic methodology is developed for the synthesis of an ethano-bridged prostaglandin endoperoxide analogue using the selective ozonolysis of a double bond in the presence of an acetylenic bond as a key step. The second part of Chapter IV details our unsuccessful efforts to synthesize an etheno-bridged prostaglandin endoperoxide analogue by the reaction of soft carbanions with nonbornadiene-palladium dichloride.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Narayanan, Krishnaswamy, "Organomercury, -rhodium and -palladium intermediates in organic synthesis " (1985). Retrospective Theses and Dissertations. 8736.