silver perchlorate; calcium carbonate in tetrahydrofuran; diethyl ether T=20°C; 20 h; Yield given. Yields of byproduct given;

palladium diacetate; caesium carbonate; 9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene in 1,4-dioxane T=80°C; 16 h; Inert atmosphere; chemoselective reaction;

1: 52 percent / triethylamine / dimethylformamide / 18 h / 85 - 90 °C 2: silver perchlorate, calcium carbonate / tetrahydrofuran; diethyl ether / 20 h / 20 °C View Scheme

trifluoroacetic acid