Group 4 metal-promoted oxidations asymmetric oxidation of sulfides

Group 4 metal-promoted oxidations asymmetric oxidation of sulfides 

CautionI Employ the standard precautions outlined in the introduction to this chapter for this reaction. Strong acids, transition metal salts, or metal syringe needles should never be added to concentrated 6u OOH stock solutions. Aliquots of Bu OOH remaining after use in reactions should not be returned to stock solutions. 1,2-Dichloroethane should not be used as a solvent for Bu OOH, despite early recommendations.  

Promptly assemble the glassware as in Fig. 1.1 and start the inert gas flow. Apply one drop of liquid paraffin to the sleeve adapter of the paddle stirrer to ensure an air-tight fit. Weigh diethyl L- -t-)-(/ ,f )-tartrate (2.5 g, 12.1 mmol) into the 50 mL Erlenmeyer flask, dissolve it in 30 mL of dichloromethane and pour this solution into the reaction flask using the funnel (lift it slightly to avoid air locks). Rinse the Erlenmeyer flask with a further 50 mL of dichloromethane and add this to the reaction flask as well. 

Cap the remaining 19/22 joint with a septum and commence stirring. Draw up 1.8 mL of titanium(IV) isopropoxide into a 5 mL syringe as shown in Fig. 1.2. Inject this into the reaction flask through the septum. 

Measure 180 ji,L of water into the 250 [xL syringe and add this to the reaction mixture through the septum (guide the fine needle with your thumb and forefinger to avoid bending it). Stir the very pale yellow solution for 20 min at room temperature. 

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