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Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
A Stable Bis(benzocyclobutadiene)-Annelated Tetraazapentacene Derivative
Philipp Biegger1, Manuel Schaffroth1, Olena Tverskoy1
1Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
Abstract:
Biphenylene-2,3-dione is a powerful reagent to build up cyclobutadiene-containing azapolyheterocycles. The target structures are formed in high yields through classical condensation of suitable aromatic diamines with the biphenylenedione. To achieve the title compound, the biphenylenedione is coupled with a diaminobenzothiadiazole derivative. Reductive cleavage of the thiadiazole ring and subsequent condensation with the biphenylenedione gives the title compound in which a central tetraazapentacene is flanked by two benzocyclobutadiene units. This compound is stable despite its extended π-system and its optical features are blueshifted in comparison to those of the symmetrical tetraazapentacene.
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