1: With boron tribromide in dichloromethane; chloroform T=0 - 20°C; 6 h; Inert atmosphere; 2: With methanol in dichloromethane; chloroform Inert atmosphereCooling with ice;

palladium diacetate; sodium t-butanolate; tri-iso-propyl phosphine in toluene 0.5 h; Reflux;

1: tris-(dibenzylideneacetone)dipalladium(0); 1,1'-bis-(diphenylphosphino)ferrocene; sodium t-butanolate / toluene / 110 °C / Inert atmosphere 2: boron tribromide / dichloromethane / 3 h / -80 - 20 °C View Scheme

1: tris-(dibenzylideneacetone)dipalladium(0); 1,1'-bis-(diphenylphosphino)ferrocene; sodium t-butanolate / toluene / 110 °C / Inert atmosphere 2: boron tribromide / dichloromethane / 3 h / -80 - 20 °C View Scheme

1.1: tris-(dibenzylideneacetone)dipalladium(0); 1,1'-bis-(diphenylphosphino)ferrocene / toluene / 0.17 h / 20 °C / Inert atmosphere 1.2: 22 h / 90 °C 2.1: tris-(dibenzylideneacetone)dipalladium(0); 1,1'-bis-(diphenylphosphino)ferrocene / toluene / 0.17 h / 20 °C / Inert atmosphere 2.2: 20 h / 90 °C 3.1: boron tribromide / dichloromethane / 3 h / -80 - 20 °C View Scheme

1.1: tris-(dibenzylideneacetone)dipalladium(0); 1,1'-bis-(diphenylphosphino)ferrocene / toluene / 0.17 h / 20 °C / Inert atmosphere 1.2: 20 h / 90 °C 2.1: boron tribromide / dichloromethane / 3 h / -80 - 20 °C View Scheme

toluene-4-sulfonic acid in toluene 12 h; Heating;