Palladium-catalyzed coupling of aryl iodides with 2-alkynylbenzonitriles

The reaction of 2-(2-phenylethynyl)benzonitrile (1a) with aryl iodides, in the presence of Pd(PPh3)(4) and NaOCH3 in CH3OH, at refluxing temperature f or 24 h, gave 3-diarylmethylideneisoindoles 3a-d in 18-56% yields. When 2-( 1-hexynyl)benzonitrile (1b) was employed in this reaction, isoquinolines 2a -c were obtained in 29-34% yields and isoindoles 3e-g were obtained in 12-2 5% yields, respectively. Reaction of 2-ethynylbenzonitrile (1c) with 2.5 eq uiv, of iodobenzene for 48 h gave 3a in 45% yield along with the monocouple d adduct 3h in 6% yield. (C) 2000 Elsevier Science Ltd. All rights reserved .