Table 3. Scope of the reaction of aryldiazonium tetrafluoroborate with benzofuran and benzothiophene a .
aReaction conditions: 0.5 mol% Pd(OAc)2, 1.0 mmol heteroarene and 1.2 equiv. aryldiazonium tetrafluoroborate in 5 mL MeOH at rt, open flask, after full conversion: reflux with 5.0 equiv. acetyl chloride for 15 min.
b2.0 mol% Pd(OAc)2, 2.0 equiv. aryldiazonium tetrafluoroborate at 40 °C.