One-pot relay reduction–isomerization of β-trifluoromethylated-α,β-unsaturated ketones to chiral β-trifluoromethylated saturated ketones over combined catalysts in aqueous medium

Abstract

Despite great achievements obtained in tandem reactions, a solution for the incompatible nature of bimetal complexes participating in a multi-step catalytic process is still an unmet challenge. Herein, we utilize a functionalized periodic mesoporous organosilica with well-defined single-site chiral organoruthenium active centers in its ordered dimensional-hexagonal mesopores as a heterogeneous catalyst, and combine it with [RuCl₂(PPh₃)₃] to enable an efficient one-pot relay reduction–isomerization from achiral β-trifluoromethylated-α,β-unsaturated ketones to chiral β-trifluoromethylated saturated ketones in water with up to 97% ee and 100% enantiospecificity, supplying a gap in their incompatibility. Furthermore, the heterogeneous catalyst can be recovered conveniently and reused repeatedly at least eight times without loss of reactivity in the enantioselective reduction of 4,4,4-trifluoro-1,3-diphenylbut-2-enone, showing it to be particularly attractive in the practice of organic synthesis in an environmentally friendly manner.