Palladium-catalyzed Reaction of Allyl Acetate, Allyl Benzoate, Allyl Chloride, Allyl Bromide, Diallyl Ether, and Allyl Alcohol with Benzene

Abstract

The phenylation reaction of allyl compounds with benzene using the Pd(OAc)₂, /AcOH and Pd(CF₃CO₂)₂/CF₃COOH systems has been investigated. The reaction of ally! esters su ch as allyl acetate [12] and benzoate [14] with benzene in the Pd(OAc)₂/AcOH system gave the usual phenylation products. The reaction of allyl halides, especially chloride [16]with benzene gave not only monophenylated product [17] but also di- and triphenylated products [18], [19], [20], [21] and [22]. Addition of PPh₃ resulted in the selective formation of [19]. On the other hand, the reaction with the Pd(CF₃CO₂)₂/CF₃COOH system gave the acyl-O bond fission-phenylation products; reactions of ally! acetate [12] and benzoate [14 ]with benzene gave cinnamaldehyde [29] and 3, 3-diphenylpropenal [32] Addition of pbenzoquinone as an oxidizing agent made the reaction catalytic with respect to palladium. The mechanisms of these reactions are also discussed.