Facile synthesis of tribenzosilepins from terphenyls and dihydrosilanes by electrophilic double silylation.

Tribenzosilepins were synthesized from terphenyls and dihydrosilanes via a facile approach using a double sila-Friedel-Crafts reaction. Several silepin derivatives were obtained in moderate to high yield. The reaction system was found to be suitable for synthesizing a bidirectional silepin. Furthermore, the transformation of the amino groups of tribenzosilepin derivatives to aryl groups and the extension of the backbone π-system in tribenzosilepin were demonstrated.