Palladium-Catalyzed α-Arylation of Oxindoles

Abstract

A catalyst generated from Pd(dba)2 and the bulky electron-rich phosphine ligand 2-(dicyclohexylphosphino)-2',4', 6'-tri-i-propyl-1-1'-biphenyl is effective for the alpha-arylation of oxindoles. Generation of the potassium-enolates of a range of oxindoles allows coupling with aryl chlorides, bromides, and triflates. Significant variation of the substitution pattern on both the oxindole and aryl halide is possible.

Bisannulation of 2,3‐Dichloro‐1,4‐naphthoquinone with o‐Nitrophenylacetic Acid Derivatives: A Succinct Synthesis of the ABCD Ring System of Alpkinidine

“…Presumably this was, in part, due to competing reaction through the lactam nitrogen. We therefore attempted the reaction again with the N ‐Boc derivative (i.e., 33 ) 20. In this case, the desired adduct was isolated, albeit in low yield.…”

“…tert ‐Butyl 3‐(3‐Chloro‐1,4‐dioxo‐1,4‐dihydronaphthalen‐2‐yl)‐2‐oxoindoline‐1‐carboxylate (34): 2,3‐Dichloro‐1,4‐naphthoquinone ( 16 ; 45 mg, 1.9 mmol) was added to a stirred mixture of N ‐ tert ‐butyl 2‐oxoindoline‐1‐carboxylate ( 33 ;20 0.60 g, 2.6 mmol), K 2 CO 3 (1.06 g, 7.67 mmol), and DMF (40 mL) at 50 °C. After 4 h, the suspension was cooled and diluted with H 2 O (100 mL) and HCl (1 M ; 20 mL), then it was extracted with EtOAc (3 × 30 mL).…”

Metallkatalysierte α‐Arylierungen von Carbonylen und verwandten Molekülen: aktuelle Trends bei der C‐C‐Kupplung über C‐H‐Funktionalisierung

“…Willis und Durbin berichteten über eine zweite Anwendung des auf 14 basierenden Systems für die α‐Arylierung von Amiden (Tabelle 18). Dabei entstanden Oxindole im Allgemeinen in geringeren Ausbeuten als mit Hartwigs Pd/PCy 3 ‐Katalysatorsystem 90…”

α‐Arylation Processes

“…Aryl bromides, chlorides, and triflates were all viable substrates in this intermolecular reaction (Scheme 8.48) [87]. Significant variation of the aryl coupling partner was possible, with both electron-rich and electron-poor substituents.…”