One‐Pot Shotgun Synthesis of Earring‐Shaped and Jaw‐Like Porphyrin Macrocycles

A one‐pot, shotgun platinum‐mediated macrocyclization strategy for the synthesis of earring‐shaped and jaw‐like porphyrin macrocycles is reported. From the coupling of a 2,12‐diborylated Ni(II) porphyrin precursor with excess bis(4‐borylphenyl)methane, three earring‐shaped monoporphyrins ( ER2 , ER3 , and ER4 ) bearing bridges of two, three, and four bis(4‐phenylene)methane units, along with a jaw‐like dimer ( JW ) featuring two independent bridges at the 2‐2′ and 18‐18′ positions, were obtained in a single reaction. 1 H NMR spectroscopy reveals a progressive downfield shift of the meso protons as the bridge length increases from ER2 to ER4 , consistent with gradual release of ring strain. The X‐ray structure of JW confirms a curved jaw‐like geometry with a dihedral angle of 119.65° between the two porphyrin planes, and the two porphyrin rings exhibit distinct degrees of saddle‐shaped distortion. UV/Vis absorption shows a large bathochromic shift from ER4 to ER3 (12 nm) but only a marginal shift from ER3 to ER2 (1 nm). This work demonstrates that divergent one‐pot cyclization is a powerful strategy for accessing strained porphyrin macrocycles with different ring sizes and architectures, providing an efficient platform for systematic structure–property studies.