Modular Synthesis of trans‐A$_{2}$B$_{2}$‐Porphyrins with Terminal Esters: Systematically Extending the Scope of Linear Linkers for Porphyrin‐Based MOFs

Differently functionalized porphyrin linkers represent the key compounds for the syntheses of new porphyrin‐based metal–organic frameworks (MOFs), which have gathered great interest within the last two decades. Herein we report the synthesis of a large range of 5,15‐bis(4‐ethoxycarbonylphenyl)porphyrin derivatives, through Suzuki and Sonogashira cross‐coupling reactions of an easily accessible corresponding meso‐dibrominated trans‐A$_{2}$B$_{2}$‐porphyrin with commercially available boronic acids or terminal alkynes. The resulting porphyrins were fully characterized through NMR, MS, and IR spectroscopy and systematically investigated through UV/Vis absorption. Finally, selected structures were saponified to the corresponding carboxylic acids and subsequently proven to be suitable for the synthesis of surface‐anchored MOF thin films.