Silver-catalyzed selectively reduction of the C=C bond of an α,β-unsaturated ketones in water
The selective reduction of C=C bond in α,β-unsaturated ketones is one of the highly potent and challenging functional group transformations in organic chemistry.Therefore,the investigation of a simple and efficient new reductive system for the chemoselective reduction of α,β-unsaturated ketones is highly desirable.Herein,we presented a method for the homogeneous hydrogenation of C=C bond in the α,β-unsaturated carbonyl compound to produce ketone using low catalyst loading and air-stable silver N-heterocyclic carbene complexes as the catalyst and PhSiH3 as the source of hydrogen.A wide range of α,β-unsaturated ketones,featuring diverse functional groups,were selectively transformed into their corresponding ketones with moderate yields.This process can be readily scaled up and exhibits compatibility with various sensitive functional groups,including fluorine,chlorine,bromine,trifluoromethyl,aminomethyl,cyano and ester,with broad scope and particularly high turnover numbers(up to 11250).Notably,this catalytic methodology finds application in the synthesis of essential drug compounds.Meanwhile,the post-processing operation is simple and does not require hydrogen or autoclave equipment.Mechanistic investigations suggest that the in-situ-generated Ag-H species may serve as active intermediates.Intermediate is produced by the coordination of the C=C to AgH species,which is succeeded by the production of intermediate via the insertion of the C=C bonds into the Ag-H bond.The final product was obtained by hydrolysis intermediate in the presence of H2O.
万方数据
维普
