Cryo-mechanochemical synthesis of free-base and metal A₃-corroles and A₄-porphyrins: A solvent-free approach

We report a mechanochemical method for synthesizing freebase corroles via the reaction of pyrrole with substituted benzaldehyde precursors. The study emphasizes the one-pot cryo-mechanochemical synthesis of 5,10,15-Tris-(TIPS-ethynyl)corrole (A 3 -TIPS-ethynylcorrole) and 5,10,15,20-Tetrakis-(TIPS-ethynyl)porphyrin (A 4 -TIPS-ethynylporphyrin) through ball-milling condensation. Subsequent oxidation with [Formula: see text]-chloranil produced freebase corroles and porphyrins with yields of 40% to 70%, representing nearly a threefold increase over the previously developed MeOH/H 2 O-based approach. Quantitative metalation of these freebase compounds was achieved in the ball mill at elevated temperatures. This method also improved the EcoScale values and significantly reduced the E-factor, highlighting its environmental benefits compared to traditional synthesis techniques.