All-aza smaragdyrin, a historic but elusive pentapyrrolic macrocycle, was successfully synthesized and characterized for the first time. [22]­Smaragdyrin BF2-complex 3 was smoothly synthesized by 2-fold SNAr reaction of 1,9-dibromo-5-mesityldipyrrin with 5,10-dimesityltripyrrane. Treatment of 3 with methanesulfonic acid gave [20]­smaragdyrin 5 as a stable antiaromatic compound. Reduction of 5 with NaBH4 under inert conditions gave [22]­smaragdyrin 6 as an aromatic congener, which was easily oxidized back to 5 in the air. Complex 3 was interconvertible with its 20π-congener 4 via oxidation with MnO2 and reduction with NaBH4. Treatment of 3 or 4 with CuCl2 in the presence of NaOAc gave hetero bimetal complex 8.

22]Smaragdyrin BF 2 complex (S)-Ni II porphyrin (P) fused hybrids were synthesized through Suzuki-Miyaura coupling of brominated S with borylated P and subsequent oxidative fusion reaction with FeCl 3 as the first example of directly fused porphyrinoids bearing cycloheptatriene linkage. These fused hybrids have been fully characterized, including their Xray structural analysis. Owing to the cycloheptatriene linkage, these fused hybrids adopt waving structures. These fused hybrids display red-shifted and enhanced Q-like bands and characteristic redox potentials, depending upon the constitution and the linking position.

[22]Smaragdyrin BF2 complex (S)‐NiII porphyrin (P) fused hybrids were synthesized through Suzuki–Miyaura coupling of brominated S with borylated P and subsequent oxidative fusion reaction with FeCl3 as the first example of directly fused porphyrinoids bearing cycloheptatriene linkage. These fused hybrids have been fully characterized, including their X‐ray structural analysis. Owing to the cycloheptatriene linkage, these fused hybrids adopt waving structures. These fused hybrids display red‐shifted and enhanced Q‐like bands and characteristic redox potentials, depending upon the constitution and the linking position.