It was found that an air-stable NHC–palladium complex of Pd [(s)-3-C3H5-4-(C5H5CH2)-1- (2, 6-iPr2C6H3)-C3H3N2](C5H5N) Br2 derived from l-phenylalanine is an effective pre- catalyst for copper-free and phosphine-free Sonogashira reaction of alkynes under aerobic conditions in short reaction time. Moreover, the palladium compound would be reused to catalyze the hydroarylation of alkyne prepared from Sonogashira reaction, which makes ...