Microwave-Assisted [4+2] Diels-Alder Cycloaddition of 1,4-Diethynyl Triptycene with Various Cyclopentadienone Derivatives: Promising Building Blocks for Polymer Networks

Triptycene derivatives substituted at their 1,4- positions with tetraphenylbenzene and diphenyltriphenylene moieties were prepared by microwave-assisted [4+2] Diels-Alder cycloaddition reactions in very good yields. The target compounds were characterized by H-1 and C-13 NMR spectroscopy, HRMS, UV/Vis and emission spectrophotometry. In addition, single crystal XRD spectra for two of these derivatives are presented. The tetra- and octabrominated triptycene compounds underwent palladium-catalyzed Suzuki-Miyaura cross-coupling reactions affording the desired products in very good yields. This successful tetra- and octa-fold substitution paves the way for the employment of these building blocks to prepare polymer networks for various applications.