RuHCl(CO)(PPh₃)₃-Catalyzed Chemoselective Transfer-Hydrogenation of Enones Leading to Saturated Ketones

Abstract

The highly chemoselective transfer-hydrogenation of α,β-unsaturated ketones to give saturated ketones was achieved using RuHCl(CO)(PPh₃)₃ as a catalyst. In addition to α,β-unsaturated ketones, other enones, containing a remote C=C bond, were also reduced to give saturated ketones in good to excellent yields with high selectivity.

transfer-hydrogenation - enones - ruthenium hydride complexes - ketones - chemoselective

References and Notes

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<A NAME="RU00606ST-7">7</A>

General Procedure for the Transfer-Hydrogenation of Enones Catalyzed by RuHCl(CO)(PPh ₃ ) ₃ . Benzene (3 mL), 1h (146 mg, 1 mmol), 2-propanol (65.4 mg, 1.09 mmol) and RuHCl(CO)(PPh₃)₃ (28.7 mg, 0.03 mmol) were placed in a 30-mL two-necked flask equipped with a reflux condenser and a magnetic stirring bar under an atmosphere of N₂. The mixture was stirred at 70 °C (bath temperature) for 6.5 h. After removing the solvent, the residue was purified by column chromatography on silica gel (20% EtOAc-hexane as eluent). The eluent contained 2h (144 mg, 97%).