1: potassium carbonate; tris-(dibenzylideneacetone)dipalladium(0); 9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene / 1,4-dioxane / 16 h / 100 °C / |Inert atmosphere 2: 2-(tert-butyl)-1,1,3,3-tetramethylguanidine / N,N-dimethyl-formamide / 10 h / 80 °C 3: trifluoroacetic acid / dichloromethane / 2 h / 10 - 20 °C 4: triethylamine; benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride / tetrahydrofuran; N,N-dimethyl-formamide / 10 h / 20 °C View Scheme