(R)-(+)-1,1'-Bi-2-naphthol

Typical Procedure: Synthesis of 2
In a 25 mL round-bottom flask (R)-(+)-BINOL (1.2 eq.) is dried under vacuum for 30 min and dissolved in THF (10 mL). The mixture is cooled to －78 °C, and PhLi (2.4 eq.) is added dropwise under inert atmosphere. Then the mixture is warmed to ambient temperature and stirred for 30 min. The colorless reaction mixture is cooled again to －78 °C, and 4-phenylpyridine N-oxide or pyridine N-oxide (1.0 eq.) is added. The mixture is allowed to reach room temperature, where it is stirred for another 60 min. A yellow mixture is obtained and cooled to －78 °C. To this cooled mixture, R¹MgBr (3 eq.) in THF is added dropwise and stirred for 40 min (followed by LC-MS). A fresh NaBH₄ (3 eq.) suspension in MeOH (2 mL) is added to the mixture, which thereafter is allowed to reach room temperature. CH₂Cl₂ (20 mL) and H₂O (10 mL) are added to the reaction mixture, and the organic layer is shaken with 10%NaOH aq. (3×10 mL) and then washed with H₂O, dried (Na₂SO₄) and concentrated under reduced pressure. The crude reaction mixture is purified by flash silica column chromatography (AcOEt―Heptane).