Copper-catalyzed intermolecular oxyamination of olefins using carboxylic acids and O-benzoylhydroxylamines

Abstract

SummaryThis paper reports a novel approach for the direct and facile synthesis of 1,2-oxyamino moieties via an intermolecular copper-catalyzed oxyamination of olefins. This strategy utilizes O-benzoylhydroxylamines as an electrophilic amine source and carboxylic acids as a nucleophilic oxygen source to achieve a modular difunctionalization of olefins. The reaction proceeded in a regioselective manner with moderate to good yields, exhibiting a broad scope of carboxylic acid, amine, and olefin substrates.

Copper-Catalyzed Modular Amino Oxygenation of Alkenes: Access to Diverse 1,2-Amino Oxygen-Containing Skeletons

“…The reactions of amide 4a and dione 4d resulted in analogous TEMPO trapping products 9 and 11. These result coincided with our earlier results 11a (Scheme 2A), indicating that the amino etherification reaction was initiated by electrophilic amination of O -benzoylhydroxylamines followed by oxygen trapping as a secondary step. 15 However, the reaction of oxime 4f in the presence of TEMPO did not provide expected TEMPO-trapping product 13 , but resulted in exo -cyclization product 14 with TEMPO trapping at the different vinyl position.…”

“…Our studies began with the amino etherification reaction using the tertiary alcohol 1a and 4-benzoyloxymorpholine 2a as model substrates (Table 1). Under previously established amino lactonization conditions (entry 1), 11a desired product 3a was obtained in 36% yield. Among various additives examined (entries 2–8), pyridinium p -toluenesulfonate (PPTS) was found to be most effective, increasing the formation of 3a to 66% yield (entry 8).…”

“…In our own efforts in developing copper-catalyzed alkene amino difunctionalization methods, we recently reported an amino lactonization reaction that is enabled by a new alkene activation pathway involving O -benzoylhydroxylamine-mediated amination. 11 Such an alkene activation presents great potential as a powerful amination strategy in an analogous manner to electrophilic halogen and chalcogen reagents. 12 Herein, we report that this copper-catalyzed electrophilic alkene amination pathway enables the nucleophilic incorporation of different oxygen sources, such as alcohols, amides, oximes, and even thiocarboxylic acids for the synthesis of diverse amino-containing skeletons (Scheme 1).…”

Copper‐Catalyzed Intermolecular Aminooxygenation of Styrenes using N‐Fluorobenzenesulfonimide and Simple Alcohols

“…Under these conditions, aminooxygenation product 2a was not obtained, and the reaction only produced TEMPO derivative 7 in 15 %y ield (Scheme 5). On the basis of these preliminaryr esultsa nd other similaro nes reported previously, [10][11][12][13][14][15][16] ap ossible mechanism was proposed (Scheme 6).…”

“…[1,2] Intermolecular transition-metal-catalyzed aminooxygenations have been reported with the involvement of Os,R h, Pd, Fe, and Cu. [3][4][5][6][7][8][9][10] Homogeneous copper-catalyzed vicinal difunctionalization of alkenes is av ery active field, because of the low cost and toxicityo ft he catalysts as well as the variety of reactions that can be performed. [11] In addition, N-fluorobenzenesulfonimide (NFSI) is ar eagent used in fluorination, oxidation, and amination reactions.…”