Preparation of a Rigid and nearly Coplanar Bis-Tetracene Dimer through Application of the CANAL Reaction

A rigid tetracene dimer with a substantial interchromophore distance has been prepared through the application of the recently developed catalytic arene-norbornene annulation (CANAL) reaction. An iterative cycloaddition route was found to be unsuccessful, and so a shorter route was adopted whereby fragments were coupled in the penultimate step to form 13 : 1 mixture of two diastereomers, the major of which was isolated and crystallized. Constituent tetracene moieties are linked with a rigid, well-defined bridge, and feature a near co-planar mutual orientation of the acenes.