■ EXPERIMENTAL SECTION
General Methods. 1H and 13C NMR spectra were recorded with CDCl3 as the solvent and TMS as an internal standard. The palladacycle catalyst was prepared according to the reported literature procedure.6a The other chemicals were bought from commercial sources and used as received, unless otherwise noted.Typical Procedure for the Palladacycle-Catalyzed Deacetonative Sonogashira Coupling of 4-Aryl-2-methyl-3-butyne-2-ols with Aryl Chlorides. Aryl chloride (0.4 mmol), 4-aryl-2-methyl-3-butyne-2-ol (0.5 mmol), K2CO3 (1.0 mmol), palladacycle (1 mol %), and Xphos (4 mol %) were dissolved in CH3CN (2 mL) in a 10 mL vial under a nitrogen atmosphere. The reaction was carried out at 110
°C (oil bath temperature) for 16 h. After the reaction was finished, the mixture was filtered through a pad of Celite and extracted with brine and ethyl acetate three times. The combined organic layers were dried over anhydrous Na2SO4 and filtered. After removal of the solvent in vacuum, the residue was purified by flash column chromatography on silica gel (hexane/ethyl acetate) to afford the pure product.