Copper(II) Acetate Monohydrate

Typical Procedure:
To a 20 mL two-necked flask with a reflux condenser and a rubber cap are added 2-aminobiphenyls (0.5 mmol), [Cp*IrCl₂]₂ (0.01 mmol, 8.0 mg), Cu(OAc)₂ (0.1 mmol, 18 mg), pivalic acid (1 mmol, 102 mg), 1-methylnaphthalene (ca. 30 mg) as an internal standard, and N-methyl-2-pyrrolidone (NMP, 3 mL). Then, the resulting mixture is stirred under air at 120 °C for 3-6 h. After cooling, the reaction mixture is extracted with ethyl acetate (100 mL). The organic layer is washed by aqueous NaHCO₃ (100 mL×3), and dried over Na₂SO₄. After evaporation of the solvents under vacuum, the product is isolated by column chromatography on silica gel using hexane-ethyl acetate (10:1) as the eluent.

Typical procedure: Under an air atmosphere, a Schlenk tube is charged with Cu(OAc)2·H2O (4.0 mg, 0.02 mmol), dppf (16.6 mg, 0.03 mmol), arylboronic acid (0.4 mmol), aldehyde (0.2 mmol), NaOAc (49.2 mg, 0.6 mmol), and toluene (3 mL) under ice-salt (-20 °C). The mixture is stirred for 0.5 h at room temperature, refluxed for 24 h, and then cooled in a Schlenk tube to room temperature. The mixture is extracted with ethyl acetate (4×5 mL), and the organic layers are washed with water. The organic layers are dried over MgSO4, concentrated, and purified by flash column chromatography on silica gel to give the desired product.