In(III)-Catalyzed Direct Regioselective Syntheses of 1-Naphthaldehyde Derivatives via a Hidden Aldehyde 1,3-Translocation and Disjointed CO2 Extrusion

Abstract

A highly regioselective annulation of 3-formylchromones with alkynes in the presence of indium triflate leads to the direct construction of diverse 1-naphthaldehyde derivatives. This one-pot de novo protocol features an unusual aldehyde 1,3-translocation and disjointed CO2 extrusion. This methodology is effective for the construction of structurally diverse 1-naphthaldehydes bearing chiral moieties and polyaromatics. These naphthaldehydes can be further easily elaborated into a wide variety of functional groups. Density functional theory computations show that this In(III)-catalyzed reaction appears to proceed via a stepwise dearomative cyclization, lactonization, ring contraction, and, finally, extrusion of CO2. Most interestingly, the aldehyde translocation occurs not by the transposition of the aldehyde but rather by the skeletal rearrangement of the substrate arene.