CHELATION-CONTROLLED, PALLADIUM-CATALYZED ARYLATION OF ENOL ETHERS WITH ARYL TRIFLATES - LIGAND CONTROL OF SELECTION FOR ALPHA-ARYLATION OR BETA-ARYLATION OF [2-(DIMETHYLAMINO)ETHOXY]ETHENE

Palladium-catalyzed arylation reactions of [2-(Dimethylamino)ethoxy]ethene (1) with a series of aryl triflates were performed under a variety of reaction conditions. In particular, the influence of phosphine ligands and halide additives on regioselectivity were studied. It was found that the chelation-controlled arylation of 1 affords an expedient route for the conversion of phenols into arylacetaldehydes. Alternatively, the same starting materials could be used to synthesize acetophenones by reversing the regioselectivity with bidentate phosphine ligands.