1.1: boron tribromide; N-ethyl-N,N-diisopropylamine / dichloromethane / 12 h / 0 - 25 °C / Inert atmosphere 2.1: triethylamine / dichloromethane / 5 h / 25 °C / Inert atmosphere 3.1: tetrakis(triphenylphosphine) palladium(0); sodium carbonate / water; toluene / 12 h / Reflux 4.1: methyl trifluoromethanesulfonate / toluene / 2 h / 100 °C / Inert atmosphere 4.2: 0.5 h / Reflux; Inert atmosphere View Scheme