4-(N,N-dimethlyamino)pyridine in dichloromethane T=20°C; 3 h;

lithium diisopropyl amide in tetrahydrofuran; hexane T=-78°C;

1: n-butyllithium / tetrahydrofuran / 1 h / -78 °C 2: trifluoroacetic acid / dichloromethane / 0.5 h / 20 °C View Scheme

1.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.17 h / 0 °C / Inert atmosphere 1.2: 2 h / 20 °C / Inert atmosphere 2.1: trifluoroacetic acid / dichloromethane / 3 h / Inert atmosphere View Scheme

1: n-butyllithium / tetrahydrofuran / 1 h / -78 °C 2: trifluoroacetic acid / dichloromethane / 0.5 h / 20 °C 3: trifluoroacetic acid / acetic acid / 24 h / 140 °C 4: diphenyl phosphoryl azide / 1,3-dimethyl-imidazolidin-2-one; toluene / 2 h / 140 °C 5: 140 °C 6: trifluoroacetic acid / dichloromethane / 0.5 h / 20 °C 7: methylamine / ehanol / 2 h / 90 °C View Scheme

9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene; sodium t-butanolate; tris(dibenzylideneacetone)dipalladium (0) in tetrahydrofuran Heating;

9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene; sodium t-butanolate; tris(dibenzylideneacetone)dipalladium (0) in tetrahydrofuran Heating;

9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene; sodium t-butanolate; tris(dibenzylideneacetone)dipalladium (0) in isopropyl alcohol; toluene T=85°C;

9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene; sodium t-butanolate; tris(dibenzylideneacetone)dipalladium (0) in isopropyl alcohol; toluene T=85°C;

9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene; sodium t-butanolate; tris(dibenzylideneacetone)dipalladium (0) Heating;