Stereoretentive Iron‐catalyzed Cross‐coupling of an Enol Tosylate withMeMgBr
Abstract
A. Methyl (Z)-2-phenyl-3-(tosyloxy)acrylate [(Z)-1)]. A 300-mL, threenecked, round-bottomed flask is attached to a CaCl2 drying tube, which is capped with a glass stopper, and fitted with a thermometer and a Tefloncoated magnetic stir bar (Note 2). Methyl 2-phenylacetate (10.54 g, 70 mmol) (Note 3), methyl formate (6.52 mL, 105 mmol) (Note 4), and THF (70 mL) (Note 5) are added and a septum is added to the middle neck. The vigorously stirred colorless solution is immersed in an ice-cooling bath, and sodium tertbutoxide (NaOt-Bu) (10.12 g, 105 mmol) (Note 6) is added in 5 portions over 5 ~ 10 min after temporarily removing the septum while maintaining the inner temperature below 10 °C (Figure 1). The suspension becomes a wellmixed pale yellow slurry (Figure 2) ca. 5 min after the addition of NaOt-Bu. A.