Arylation of Azlactones using Diaryliodonium Bromides and Silver Carbonate: Facile Access to α‐Tetrasubstituted Amino Acid Derivatives

Abstract

With the combined use of silver carbonate, diaryliodonium bromides were successfully utilized as aryl source to realize the highly efficient arylation of azlactones under mild conditions. The reaction worked well with various alkyl-and aryl-substituted azlactones, providing a range of a-tetrasubstituted amino acid derivatives in moderate to high yields.

Advances in Synthetic Applications of Hypervalent Iodine Compounds

“…Transition metal-catalyzed arylations of organic substrates with diaryliodonium salts have been summarized in several reviews and books. ,,,, Recently, numerous regio- and stereoselective arylations in inter- or intramolecular mode using transition metal catalysts, such as copper, − palladium, − silver, nickel, iron, iridium, and ruthenium, have been reported. Particularly important is the copper-catalyzed, directed meta -selective C–H arylation of aromatic compounds with amido substituents reported by Gaunt .…”

Polyfluoroarylation of oxazolones: access to non-natural fluorinated amino acids

“…4 α-Arylation of the oxazolone enolate has been accomplished via Ag-mediated arylation with diaryliodonium salts (Scheme 1C, eqn 1) , 4d Pd-catalyzed cross-coupling of aryl-bromides (eqn 2) , 5 and pyridine addition via nucleophilic addition to N -tosylated pyridines. 4a However, these methods do little to access amino acids that possess highly fluorinated arenes, because the requisite fluorinated starting materials are not available. Additionally, while these methods proved useful for accessing tertiary carbons, secondary carbons were never obtained.…”

“…Typically, oxazolones are not easily isolated due to their predisposition for ring opening, and instead are usually derivatized immediately to a more stable molecule. 4b This is easily accomplished under acidic conditions, since the oxazolone behaves as an activated ester. We explored the ring opening of the oxazolone with alcohols to form perfluoroaryl N- benzoyl protected esters (Table 2) .…”

tert-Butoxide-Mediated Arylation of 1-Acetylindolin-3-ones with Diaryliodonium Salts

“…4 Although C(sp 3 )-arylations of carbonyl compounds using hypervalent iodonium salts were reported in the early 1960s, 5 interest in simple, mild and metal-free arylations with other valuable nucleophiles has experienced a renaissance in recent years. 6 Manetsch reported a metal-free arylation of ethyl acetoacetate for the synthesis of 3-aryl-4(1H)-quinolones. 7 Furthermore, a mild protocol for the C-4 arylation of 4-substituted pyrazolin-5-ones with diaryliodonium salts promoted by 4-(N,N-dimethylamino)pyridine (DMAP) has been described.…”