1: 1,8-diazabicyclo[5.4.0]undec-7-ene / acetonitrile / 11 h / 50 °C / Inert atmosphere 2: o-(trimethylsilyl)phenyl trifluoromethanesulfonate; cesium fluoride / acetonitrile / 4.5 h / 20 °C / Inert atmosphere View Scheme