Silicon electronic effect in the Pauson–Khand reaction of alkynylsilanes with allenes

The β-effect of silicon was shown to be a determining factor for the regioselectivity of the Pauson–Khand reaction of alkynylsilanes with allenes. This electronic effect accounts for the formation of 3-trimethylsilyl-4-alkylidenecyclopentenones observed from monosubstituted allenes.