The Au(I) Catalyzed Activation of Allenamides and Their Subsequent Transformation into Chromanes: A Method for the Regiocontrolled Addition to the α- and γ‑Positions of the Allene Unit

Au­(I)
activation of allenamides in the presence of phenols leads
to the formation of chromanes in moderate to good yields. This catalytic
process is dependent on the counterion which facilitates the activation
of the in situ formed imine. Furthermore, this iminium
can be intercepted by trimethylallyl silane, via the Hosomi–Sakurai
reaction, giving a formal procedure for the regioselective intermolecular
addition of two carbon nucleophiles to an allenamide at the α-
and γ-positions.