Palladium-Catalyzed Carbonylative Coupling Of Benzylic Chlorides And Terminal Arynes

α,β-Unsaturated carbonyl compounds were widely in organic synthetic chemistry. Due to their special structures, which were used in many reactions, such as Michael addition reaction, Rauhut-Carrier reaction (dimerization) and Nazarov cyclization. Traditional methods for the synthesis of unsaturated carbonyl compounds include aldol condensation, Perkin reaction, Claisen-Schmidt reaction, malonic ester synthesis, Knoevenagel condensation reaction, Meyer-Schuster rearrangement. In addition,β-hydroxy aldehyde or ketone can be easily dehydrated to αβ-unsaturated aldehyde or ketone, which is a common method for the synthesis of such compounds.In this paper, palladium-catalyzed cross coupling reaction of benzylic chlorides, carbon monoxide and terminal arynes is investigated. The coupling reaction provides a simple method for the carbonylation of benzylic chlorides and the synthesis of αβ-unsaturated ketone.1. The coupling reaction of1-(chloromethyl)-2-naphthalene, carbon monoxide and phenylacetylene was selected as the model reaction. And the catalyst, pressure, solvent, temperature were optimized.5atm CO,5mmol%PdCl2(PPh3)2,1,4-dioxane.1.2equiv phenylacetylene was found as the best condition. Under the condition described above, the coupling reaction of various benzylic chlorides, carbon monoxide and terminal arynes were performed, and the maximum yield was98%.2. It was found that the reaction can tolerate a wide range of functionalities and the substrate bearing an electron-donating group on aromatic ring was benefit to this reaction.3e、3f、3g、3i、3j、3k、3m were unknown compounds and their structures were confirmed by1H NMR,13C NMR, IR and HRMS.