Spectroscopic and Crystallographic Characterization of Enantiopure Planar Chiral N-Oxazolidinoyl Diene Iron (O) Tricarbonyl complexes For Use in Diastereoselective Synthesis
Date of Award
© 2018 Nathan W. Dow. All rights reserved. This work is freely available courtesy of the author. It may only be used for non-commercial, educational, and research purposes. For all other uses, including reproduction and distribution, please contact the copyright holder.
Bachelor of Arts
Chemistry & Biochemistry
Robert S. Paley
Iron(D) tricarbonyl-diene complexes have emerged from the field of organometallics as motifs of particular importance due to their robust synthetic applications. As a result of their planar chiral configurations, these removable iron units have been effectively used as diene protecting groups, stereodirecting groups and dienyl cation stabilizers to facilitate the total synthesis of architecturally complex structures, such as pharmaceutically-relevant natural products. However, to further optimize ironeD) tricarbonyl utilization in diastereoselective synthesis, methods must be developed to direct iron-diene complexation reactions in a facially selective manner and to characterize these optical outcomes. Additionally, the established number of reactions tolerant to ironeD) tricarbonyl mediation must be expanded to facilitate the use of such methodologies on a widespread or industrial level. Herein we report the synthesis and characterization ofN-oxazolidinoyl diene ironeD) tricarbonyl complexes as model platforms to address both of these existing challenges. The use of enantiopure N-oxazolidinoyl chiral auxiliaries as directing groups has now been shown to efficiently and predictably direct facially-selective complexation reactions. Furthermore, the planar chirality of these species was ascertained via crystallographic and circular dichroism spectroscopy, the latter being a novel technique for such complexes. Efforts to utilize an N-oxazolidinoyl complex in the first intramolecular Pictet-Spengler cyclization directed by planar chirality were also undertaken, ultimately producing the most structurally demanding N-oxazolidinoyl complex synthesized to date. Lastly, projects involving novel auxiliaries, such as cyclic ureas and sulfonamides, to better direct complexation reactions are also detailed.
Dow, Nathan W. , '18, "Spectroscopic and Crystallographic Characterization of Enantiopure Planar Chiral N-Oxazolidinoyl Diene Iron (O) Tricarbonyl complexes For Use in Diastereoselective Synthesis" (2018). Senior Theses, Projects, and Awards. 230.