Simmons-Smith

(Et2Zn + CH2I2)







Examples:


Example 1



To a solution of diethylzinc (1.0M in hexane, 46 mL, 46 mmol) in DCM (200 mL) was added dropwise a solution of TFA (3.54 mL, 46 mmol) in DCM (50 mL) at 0 C over 30 min. To the mixture was then added dropwise a solution of diiodomethane (3.7 mL, 46 mmol) in DCM (50 mL) at 0 C over 45 min. The mixture was stirred at 0 C for 1 h. A solution of the SM (2.52 g, 20 mmol) in DCM (30 mL) was added, and the reaction mixture was stirred at RT overnight. The mixture was quenched with sat aq NH4Cl (200 mL) and extracted with DCM. The org layer was dried (MgSO4) and concentrated in vacuo. The resulting material was purified by silica gel chromatography (20% EtOAc/hexane) to provide the product as a colorless oil. [1.77 g, 63%]


[Patent Reference: WO2015129926, page 109, (21.5 MB)]



Example 2



Diethylzinc (40.6 mL, 40.6 mmol) and diiodomethane (9.3 g, 34.8 mmol) were added to a solution of the SM (1 g, 11.6 mmol) in DCM (80 mL) at -10 C. The reaction mixture was stirred at 0 C for 1 h, then RT for an additional 12 h. The mixture was quenched with sat aq NH4Cl and extracted with DCM (2 x 50 mL). The combined organics were dried (Na2SO4) and concentrated to provide the product as a light-colored oil. [600 mg, 52%]