Example 2: General procedure for the synthesis of compounds 1 to 5; A 25 mL round bottom flask was dried in an oven equipped with a magnetic stir bar and 2-iodo-2',4',6'-triisopropyl-3,6-dimethoxy-1,1'-biphenyl (1 g, 2.15 mmol) was added. The flask was evacuated and backfilled with argon and the process was repeated three times. Anhydrous THF (10 mL) was added via syringe and the reaction mixture was cooled to -78 °C. Over 10 min, n-butyllithium (2.5 M hexane solution, 940 μL, 2.36 mmol) was added dropwise. After stirring the reaction mixture for 30 min, dicyclohexylphosphonium chloride (2.26 mmol) was added dropwise over 10 min. Stirring was continued at -78 °C for 1 h. The mixture was then slowly warmed to room temperature and stirred for an additional 1.5 h. The reaction mixture was then stirred for 1.5 h. The reaction mixture was then heated to room temperature. The reaction mixture was filtered through a diatomaceous earth plug, which was pre-placed on silica (eluting with ethyl acetate). The filtrate was concentrated on a rotary evaporator to give a white solid. The crude product was recrystallized by acetone (ligands 2 to 5 were recrystallized by methanol) to give white crystals of the target product 2-(dicyclohexylphosphino)-3,6-dimethoxy-2',4',6'-triisopropyl-1,1'-biphenyl.
