sulfuric acid in toluene T=80°C; 3 h; Inert atmosphere;

1: sulfuric acid / toluene / 50 °C 2: potassium phosphate / palladium diacetate; 9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene / 1-methyl-pyrrolidin-2-one / 18 h / 100 °C / Inert atmosphere View Scheme

18-crown-6 ether; cesium fluoride in benzene (Ar); addn. of CsF to a mixt. of phenylacetylene and 18-crown-6 in C6H6,stirring for 5 min, addn. of tin compd., stirring at room temp. for 5-7 h; filtration through SiO2 or Al2O3, evapn.;