Gold‐Catalyzed One‐Pot Cycloisomerization/Nucleophilic Addition/Rearrangement of Acenaphthylene Carbaldehyde Derivatives.

Merging the latest advances in the field of gold catalysis and the efficiency of hexafluoro‐2‐propanol (HFIP), a gold‐catalyzed orthogonal tandem reaction has been developed to access carbocyclic ketone on naphthalene substrates. The methodology involved a cycloisomerization/nucleophilic addition and a C→O rearrangement. The HFIP solvent most probably acted as a Lewis‐acid on isochromene derivatives, through hydrogen donor bond activity. A large range of acenaphthylene carbaldehyde has been engaged in this process coupling gold catalysis and Lewis‐acid behavior of HFIP leading to cyclic ketones with a yield ranging from 15 to 91% (27 compounds). The mechanism was investigated, and the reaction most presumably occurred via a classical cyclization process followed by a [Au]‐HFIP interaction for the final rearrangement. The interest of such transformation was demonstrated by performing it on a gram‐scale. Moreover, a post‐functionalization bromination was performed, as well as the isomerization of some functionalized ketones leading to full trans derivatives with a yield ranging from 78 to 90% yields. [ABSTRACT FROM AUTHOR]