Decarbopalladation of pi-allylpalladium intermediates formed from palladium-catalyzed arylations of 3-allen-1-ols.

[reaction: see text] Unusual palladium-catalyzed arylative fragmentations of acyclic 3-allen-1-ols were observed. Oxidative addition of Pd(0) to aryl halides would form the arylpalladium halides, which added to the central carbon of allenes via carbopalladation to form the pi-allylpalladium intermediates. The pi-allylpalladium intermediates would be reductively eliminated via carbon-carbon cleavage to give the arylated dienes and the alpha-hydroxyalkylpalladium intermediates, which were further reductively eliminated to the corresponding aldehydes.