All-aza smaragdyrin, a historic but elusive pentapyrrolic macrocycle, was successfully synthesized and characterized for the first time. Smaragdyrin BF 2 -complex 3 was smoothly synthesized by 2-fold S N Ar reaction of 1,9-dibromo-5-mesityldipyrrin with 5,10-dimesityltripyrrane. Treatment of 3 with methanesulfonic acid gave smaragdyrin 5 as a stable antiaromatic compound. Reduction of 5 with NaBH 4 under inert conditions gave smaragdyrin 6 as an aromatic congener, which was easily oxidized back to 5 in the air. Complex 3 was interconvertible with its 20?-congener 4 via oxidation with MnO 2 and reduction with NaBH 4 . Treatment of 3 or 4 with CuCl 2 in the presence of NaOAc gave hetero bimetal complex 8.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry