The (4-bromo-5-methylthiophen2-yl)boronic acid (C) (4.0 g, 18.1 mmol, 1 eq), 4-iodopyridine (4.45 g, 21.7 mmol, 1.2 eq) and 50 ml THF were placed in a 200 ml Schlenk flask udner inert atmosphere. Into the stirred solution under argon 50 ml of 20% Na2CO2 solution in degassed water was added and the reaction mixture was degassed again by performing three vacuum-inert gas cycles. Pd(PPh3)4 (1.04 g, 0.9 mmol, 5 mol%) was added and the reaction mixture was heated to 85 °C for 72 h under inert gas. After cooling to RT, the product was extracted from the mixture by two 50 ml portions of dichloromethane and the organic layers were washed with H2O (2 × 50 ml) and brine (50 ml). After drying over MgSO4 the solvent was removed under vacuum yielding an orange solid as the crude product. Purification by silica gel column chromatography (EtOAc) afforded a light yellow solid (4.32 g, 93% yield) as the final product. 2 mmol, 2 eq) was dissolved in 150 ml of anhydrous THF and 2.5 n-BuLi in hexanes (5.66 ml, 14.2 mmol, 2eq) was slowly added at -78 °C udner inert gas atmosphere. The solution turns deep red and perfluorocyclopentene (neat, 1.50 g, 7.1 mmol, 1 eq) was then slowly added using a cooled syringe. The green mixture is allowed to warm to RT and then stirred overnight. After that 40 ml of 1 M HCl was added and the reaction stirred for additional 30 min. THF was removed under vacuum and the residue was neutralized using saturated aqueous Na2CO3 followed by a few extractions using DCM (3 × 50 ml) and additional washings with saturated Na2CO3 (50 ml) and brine (50 ml). The product was purified by column chromatography over alumina (DCM/AcOEt = 4:1) yielding a greenish solid which becomes white after washing with pentane (0.50 g, 14%).