A new catalytic asymmetric intramolecular aminopalladation reaction: Optimization and scope of the reaction, and elucidation of the mechanism

A new palladium(II)-catalyzed asymmetric synthesis of five-membered nitrogen heterocycles is reported. The success of this asymmetric aminopalladation reaction (AAP) is contingent upon the identification of ferrocenium-oxazoline palladacycle (FOP 2+), generated by oxidation of the ferrocenyloxazoline palladacycle (FOP 2) with silver trifluoroacetate as an optimal catalyst. This dissertation describes the development of the AAP reaction, and investigation of its scope and mechanism.; This dissertation is divided into four Chapters:; Chapter I. Some basic principles of Pd(II)-catalyzed reactions are described. The Wacker oxidation of ethylene to acetaldehyde provides a starting point for discussion of mechanism of Pd(II)-catalyzed reactions. This discussion is followed by a treatise of some recent developments in asymmetric Pd(II)-catalyzed reactions for the construction of chiral C-O, C-C and C-N stereocenters. These reactions are categorized into two classes. Type I includes oxidative Wacker-type reactions, whereas Type II includes are non-oxidative reactions that proceed without change in the oxidation state of the Pd(II) catalyst.; Chapter II. The discovery and development of the AAP reaction of (Z)-2-butenyl tosylcarbamate 2.12 is described. Optimization of the reaction conditions and catalyst are reported. Following this is an examination of the scope and limitations of this AAP reaction. Finally, the synthesis of several structurally different chiral five-membered ring nitrogen-containing heterocycles in high enantioselectivities and yields is described.; Chapter III. A background to the mechanistic studies is provided. Features and characteristics of the ferrocenyl-containing palladacycles are described. This discussion is followed by a brief analysis of the chemistry and properties of silver(I) salts, ferrocene/ferrocenium ion chemistry and Pd(III)/Pd(IV) compounds as they relate to FOP.; Chapter IV. The mechanism of the FOP 2 +-catalyzed AAP reaction of 2.12 is studied. Several physical analytical techniques including electron paramagnetic resonance, cyclic voltammetry, and UV-vis-NIR were used for characterization of the active catalyst FOP 2+. NMR spectroscopy and ESI mass spectrometry provided insight into possible intermediates along the catalytic cycle of the reaction mechanism. Finally, a proposed mechanism of this new AAP reaction is presented.