Table 2. Substrate Scope^a.

^aAll reactions were performed at 0.21 mmol of 1, 0.25 mmol of 2, 5 mol % 4e, and 0.2 mL of aqueous base in 5 mL of solvent.

^bIsolated yields after column chromatography.

^cDiastereomeric ratio was determined by ¹H NMR.

^dEnantiomeric excess was determined by chiral HPLC.

^eEnantiomeric ratio of the major diastereomer.