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

Abstract

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 1H and 13C 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.

Tuning the optical properties of ethynylene triptycene‐based copolymers via oxidation of their alkyne groups into α‐diketones

“…Synthesis of new molecular and polymer derivatives bearing triptycene has found a growing interest due to the various advantages offered by this rigid three‐dimensional aromatic structure, namely, a high chemical stability, possible functionalization at several reaction sites, and considerable internal free volume (IFV) . Moreover, it has been reported that the introduction of triptycene monomers in conjugated polymers bestow the resulting structures with an improved solubility in common organic solvents and a superior photostability in the solid state .…”

Gyroscopes and the Chemical Literature, 2002–2020: Approaches to a Nascent Family of Molecular Devices

“…The radius of the triptycenediyl segment (ca. 5.52 Å, estimated from crystal structures of related molecules and including hydrogen atoms 201 ) is much greater than those of the p-phenylene segments (2.87 Å, from Figure 32). Due to splintering and other problems, it has not proved possible to determine the crystal structure.…”

The First Anionic Thia‐Fries Rearrangement at the Cobaltocenium Cation

“…As a decomplexation of cyclopentadienones from their cyclopentadienylcobalt(I) complexes is possible by treatment with cerium ammonium nitrate, [28] the reaction provides a new access to substituted cyclopentadienone derivatives as building blocks for further syntheses of compounds such as interesting aromatic systems, [39,40] cycloheptatrienes, [41,42] anellated cyclopentanones, [43] norbornenones, [44] triptycenes, [45] and various heterocycles, [46,47] often by Diels‐Alder cycloadditions [48] …”

“…[34] Two enantiomeric molecules are connected by a water molecule forming hydrogen bridges to the carbonyl oxygen atoms. with cerium ammonium nitrate, [28] the reaction provides a new access to substituted cyclopentadienone derivatives as building blocks for further syntheses of compounds such as interesting aromatic systems, [39,40] cycloheptatrienes, [41,42] anellated cyclopentanones, [43] norbornenones, [44] triptycenes, [45] and various heterocycles, [46,47] often by Diels-Alder cycloadditions. [48] In the course of our investigations with ferrocene systems it was shown that the anionic thia-Fries rearrangement does not take place with ferrocenyl mesylate or tosylate.…”