Carbonylative cross-coupling reaction of aryl iodides with alkylaluminums by palladium complex catalysis

Abstract

Secondary and/or tertiary alcohols and unsymmetrical ketones have been obtained in moderate to good yields by the palladium-catalyzed (5 mol%) carbonylative coupling of aryl iodides with alkylaluminum compounds under very mild conditions (20–50°C, 1 atm of carbon monoxide). The type of the reaction product depended on the aluminum reagent employed. While the selective formation of secondary alcohols was observed in the reaction with i-Bu 3Al, the use of Et 3Al led to a mixture of a ketone and two alcoholic products. With Et 2AlCl predominantly unsymmetrical ketones were produced. In all cases, formation of directly cross-coupled products was not observed. DME and benzene can be used as solvents, but THF is unsuitable. Nickel catalysts were found to be ineffective for this reaction.