Scheme 2. Synthetic work and the labeling scheme for 5 and 9. Reagents and conditions: (a) Ag2CO3 (1.5 equiv.), Pd(OAc)2 (cat.), AcOH (1 equiv.), pentafluorobenzene (3 equiv.), DMF/DMSO, 120 °C. (b) 1. NaH (5 equiv.), diarylpyrrole (5 equiv.), DMF, ice bath, 2. 7a or 7b, 50 °C, overnight. (c) BAHA (12 equiv.), Et2O/THF, RT. (d) Zn amalgam or Zn powder, DCM or CDCl3, quant. (e) BAHA, (NO)[SbF6], or DDQ; DCM or MeCN, quant. (f) BAHA (10 equiv.), Et2O/THF, RT, 42%.
