Stereoselective synthesis of either (E)- or (Z)-silyl enol ether from the same acyclic α,β-unsaturated ketone using cationic rhodium complex-catalyzed 1,4-hydrosilylation

The stereoselective synthesis of either (E)- or (Z)-silyl enol ether from the same acyclic α,β-unsaturated ketone is reported. Highly (Z)-selective conditions were the use of [Rh(cod)2]BF4/DPPE at room temperature with no solvent, whereas (E)-selective conditions were the use of [Rh(cod)2]BF4/P(1-Nap)3 (1-Nap = 1-naphthyl) under refluxing dichloromethane.