Copper-Catalyzed Amino Oxygenation of Alkenes and Dienes: A Novel Amino-Initiation Pathway Using O-Benzoylhydroxylamines

Abstract

Nitrogen-containing compounds, specifically the 1,2-oxyamino moiety, are of vital importance to modern pharmaceuticals, natural products, and agrochemicals. 1,2-Difunctionalization of alkenes offers an efficient approach to assemble these scaffolds in a single step from readily available starting materials. In this dissertation, a novel copper-catalyzed amino oxygenation strategy of alkenes has been established using O-benzoylhydroxylamines as an electron-rich amine precursor and oxidant. First, copper-catalyzed amino lactonization was achieved starting with carboxylic acid-tethered alkenes. This intramolecular transformation is also applicable to alcohols, amides, 1,3-diones, oximes, and thioic acids as nucleophilic trapping partners. These reactions proceed in a facile manner, producing good yields and tolerance of a wide range of functional groups with excellent chemo- and regioselectivity. Mechanistic studies explicitly distinguish between a novel, electrophilic amination-initiation event and previously observed nucleophilic oxygenation-initiation events. Furthermore, the procedure can be adapted to carry out the reaction from the free amine as an O-benzoylhydroxylamine precursor. Finally, the intermolecular, three-component amino oxygenation reaction of alkenes was successfully developed using untethered carboxylic acids and O-benzoylhydroxylamines. The analogous three-component amino oxygenation reaction of dienes was also found to proceed effectively in a chemo-, regio-, and site-selective fashion.