A gold-catalyzed domino process to the steroid framework.

The facile formation of the B and C ring of rac-desoxyequilenin and of a chrysenone derivative in just one preparative step is demonstrated, applying a gold-catalyzed domino process, which involves a benzopyrylium cation as the key intermediate and an intramolecular [3 + 2] cycloaddition as the key step.

A platinum-catalyzed annulation reaction leading to medium-sized rings.

A platinum-catalyzed domino process with intermediate benzopyrylium cations reaches its optimum utility in the formation of 7- and 8-membered rings. With iron(III) chloride, a tetracyclic product is isolated, derived from an oxidative transformation of a metal-carbene intermediate.

Isoindoles and dihydroisoquinolines by gold-catalyzed intramolecular hydroamination of alkynes.

The title compounds are enantioselectively synthesized in just two preparative steps, making use of the Ugi-four-component reaction with an amino acid as chiral component, followed by a gold-catalyzed hydroamination.

Total synthesis of heliophenanthrone.

The total synthesis of rac-heliophenanthrone (3a) was achieved by a convergent approach, making use of a transition-metal-catalyzed domino process with an intramolecular Diels-Alder reaction at an isobenzopyrylium cation as key step.