New reactions of organoboron compounds

This Dissertation describes some new variations of a three-component reaction among boronic acids or trifluoroborates with amines and carbonyl compounds, known as the Petasis reaction. This process has been extended to include imidazole-carboxaldehydes as the carbonyl component, while trifluoroborate derivatives were shown to react with preformed or in-situ generated iminium salts to give new amine products. Similar reactions with quinoline or isoquinoline analogs were also shown to form new aza-heterocyclic derivatives.; This Thesis consists of five Chapters: Chapter 1 gives a general introduction to the chemistry of organoboron compounds and highlights some recent synthetic reactions involving boronic acids and trifluoroborates with an emphasis on reactions with amines and carbonyls.; Chapter 2 details an investigation on the use of formaldehyde and formaldehyde equivalents in the Petasis reaction, including the use of microwaves and the conversion of aryl and heteroaryl boronic acids to benzylic amines.; Chapter 3 describes the synthesis of promising medicinal scaffolds employing the reaction of amines and boronic acids with imidazole-carboxaldehydes.; Chapter 4 is focused on the use of trifluoroborates as the active species in the three component reaction with the help of a catalyst. These studies include the direct reaction of trifluoroborates with preformed iminium salt such as Eschenmoser's salt, as well as the use iminium salts generated in situ from imines.; Chapter 5 describes the three-component reaction of trifluoroborates with iminium salts generated in-situ upon the reaction of quinolines or isoquinolines with chloroformates to form aza-aromatic derivatives.