scheme4

Scheme 4. Scope of allylic sulfones^a. ^aUnless otherwise noted, the reaction was conducted with 2 (0.2 mmol), 3a (0.2 mmol), 4a(0.1 mmol), Rb₂CO₃ (0.3 mmol), (R)-1a (0.012 mmol) and Pd₂dba₃ (0.004 mmol) in MTBE (2 mL) at 0 ºC for 48 h under Ar. Isolated yields are shown. The er values were determined by SFC. ^bThe reaction was performed at 10 ºC. ^cCs₂CO₃ was used instead of Rb₂CO₃.