Synthesis of 2-Oxazolones and α-Aminoketones via Palladium-Catalyzed Reaction of β,β-Dibromoenamides

Abstract

β,β-Dibromoenamides show two different interesting reactivities based on the choice of R group under the reaction conditions. On the basis of mechanistic studies, both reactions proceed via an intermolecular Suzuki-Miyaura C-C coupling and an intramolecular C-O coupling.

Crystal structure of 4-tert-butyl-2-{2-[N-(3,3-dimethyl-2-oxobutyl)-N-isopropylcarbamoyl]phenyl}-1-isopropyl-1H-imidazol-3-ium perchlorate

“…The plane of the carbonyl group (C22/O2/C23/C21) is oriented almost orthogonal to the plane of the amide fragment (C21/N3/C18/C17/O1/C6), the angle between their mean planes being 77.87 (11) . A similar type of -acylaminoketone fragment has been observed for other N-substituted -acylaminoketones (Bartnik et al, 1998;Tinant et al, 2006;Chai et al, 2011;Hashmi et al, 2011;Su et al, 2011).…”

The Current Status of O‐Heterocycles: A Synthetic and Medicinal Overview

“…Diversely substituted oxazolonesw ere obtained by initial palladium-catalysed coupling of N-alkynyl tert-butyloxycarbamates with aryl halides, followed by oxy-palladation/reductive elimination (Scheme 4a). [43] [42] An intermolecular Suzuki-Miyaura CÀCc oupling and an intramolecular CÀOc oupling re-action within b,b-dibromoenamides affords 2-oxazolones and a-aminoketones (Scheme4c).…”

“…[42] An intermolecular Suzuki-Miyaura CÀCc oupling and an intramolecular CÀOc oupling re-action within b,b-dibromoenamides affords 2-oxazolones and a-aminoketones (Scheme4c). [43]…”

Recent advances in application of intramolecular Suzuki cross-coupling in cyclization and heterocyclization

“…Reactions of a series of b,b-dibromoenamides 192 and boronic acids via a general and efficient intermolecular Suzuki-Miyaura C-C coupling and an intramolecular C-O coupling was reported by Chai and co-workers [52]. They synthesized 2-oxazolones under the optimized conditions shown in Scheme 38.…”