2-Substituted-3-acylindoles through the palladium-catalysed carbonylative cyclization of 2-alkynyltrifluoroacetanilides with aryl halides and vinyl triflates

Article abstract of DOI:10.1016/S0040-4020(01)80766-3

The palladium-catalysed reaction of readily accessible 2- alkynyltrifluoroacetanilides with aryl halides and vinyl triflates under a carbon monoxide atmosphere (1 or 7 atm) and in the presence of potassium carbonate produces 2-substituted-3-acyl indoles in fair to good yield. The acidity of the nitrogen-hydrogen bond proved to be of primary importance for the success of the reaction. The methodology has been applied to the synthesis of pravadoline, a drug that shows analgesic activity against postoperative pain in man.