Bispidine Derivatives: Synthesis and Interactions with Lewis Acids

In this thesis, the improved synthesis and investigations into the properties of some 3,7-diazabicyclo[3.3.1]nonane (bispidine) derivatives are described. These compounds are structurally related to the naturally occurring lupanine alkaloids, they are of interest because of their cardiac antiarrhythmic function as well as their use as bases or ligands in organic chemical reactions. Their chemical properties are related to the presence of a rigid molecular scaffold with two nitrogen atoms that can be utilized for binding interactions with a variety of Lewis acids.An improved synthesis has been developed, providing access to bispidines via bispidinones while avoiding the use of highly toxic hydrazine, which is required as reducing agent in alternative methods.A series of bispidine derivatives with a variety of substituents were characterized regarding their basicity, which spans thirteen orders of magnitude. Correlations between structure and basicity are discussed and computational methods have been used to propose further derivatives with even higher basicity…

Contents

1 Introduction
1.1 Acid-Base Interactions
1.2 Bidentate Lewis Bases as Ligands
1.2.1 Bispidines for Structural Analysis
1.2.2 Previous Structural Characterization Work with Bispidinones and Bispidines
1.3 Aims of the Present Study
2 Synthesis of Substituted Bispidines and Bispidinones
2.1 Microwave-Assisted Preparation of N,N’-Dialkylbispidines from a Bispidinone Thioketal (I)
2.2 Synthesis of N,N’-Dibenzhydrylbispidine (II)
2.3 Synthesis of N,N’-Dibenzhydrylbispidinone (II)
3 Interactions with Brønsted Acids
3.1 Protonation of Bispidines
3.2 Protonation of Bispidinones
3.3 Basicity of Bispidines and Bispidinones \(II)
3.3.1 Measured Basicity Values
3.3.2 Calculated pKa Values and Correlation with Measured pKaValues
3.3.3 15N NMR Chemical Shifts
3.3.4 Structure-Property Relationship
4 Transition Metal Complexes (III)
4.1 Conformation of a (ʌ-Allyl)Pd Complex, and Dynamics in Solution
4.2 A New Type of (ʌ-Allyl)Pd Cluster (IV)
5 Conclusions.
7 Acknowledgements
8 References

Author: Toom, Lauri

Source: Uppsala University Library

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