The aryl radical route to oxindoles: dependence on temperature and tin hydride concentration
摘要:
The cyclisation of anilide 3 via an aryl radical gives both oxindole 4 and dihydroquinolone 5. The ratio of these products is shown to depend not only on the concentration of tributyltin hydride but crucially on the temperature at which the reaction is conducted. (C) 1999 Elsevier Science Ltd. All rights reserved.
light-catalyzed carbohalogenation reaction is reported. A nickel catalyst and an inexpensive phosphine ligand promote the reaction of aryl iodides and aryl bromides with π systems to enable the construction of a library of halogenated heterocyclic scaffolds. Mechanistic studies provide insight regarding fundamental steps of the catalytic cycle, including the reversible C–X bond formation via deuterium labeling
A novel visible-light-induced radical cascade bromocyclization of N-arylacrylamides has been accomplished. This reaction overcomes the overbromination at the benzene rings suffered in traditional electrophilic reactions, thus enabling the first highly chemoselective synthesis of valuable 3-bromomethyloxindoles. The combination of pyridine and anhydrous medium is identified as the key factor for the