Silver-Catalyzed Asymmetric Allylation of Ketones with Allyl Silanes

Significance

This is one of the first examples of a catalytic asymmetric Sakurai allylation of ketones. The starting allyltrialkoxysilanes are relatively easy available, stable, non-toxic compounds. In many cases, very good enantio- and diastereoselectivities were achieved. A number of unsaturated cyclic ketones give excellent results, but in the case of a linear alkyl ketone [Ph(CH₂)₂COMe] only moderate results (65% ee) were obtained. The stereo­chemical outcome of the addition is completely controlled by the catalyst, since both Z- and E-isomers of crotyl triethoxysilane give the same product. This approach may present significant advantages for natural product synthesis.