hydrogenchloride in diethyl ether T=25°C; 18 h;

1: copper(I) bromide; 1,10-phenanthroline / 56 h / 135 °C 2: 9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene; caesium carbonate; tris-(dibenzylideneacetone)dipalladium(0) / 1,4-dioxane / 18 h / |Inert atmosphere; |Reflux 3: hydrogenchloride / diethyl ether / 18 h / 25 °C View Scheme

1: copper(I) bromide; 1,10-phenanthroline / 56 h / 135 °C 2: 9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene; caesium carbonate; tris-(dibenzylideneacetone)dipalladium(0) / 1,4-dioxane / 18 h / |Inert atmosphere; |Reflux 3: hydrogenchloride / diethyl ether / 18 h / 25 °C View Scheme

1: 9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene; caesium carbonate; tris-(dibenzylideneacetone)dipalladium(0) / 1,4-dioxane / 18 h / |Inert atmosphere; |Reflux 2: hydrogenchloride / diethyl ether / 18 h / 25 °C View Scheme