Details

Autor(en) / Beteiligte

• Wang, Kaisheng
• Liu, Pingting
• Zhang, Fenni
• Xu, Ling
• Zhou, Mingbo
• Nakai, Akito
• Kato, Kenichi
• Furukawa, Ko
• Tanaka, Takayuki
• Osuka, Atsuhiro
• Song, Jianxin

Titel

A Robust Porphyrin‐Stabilized Triplet Carbon Diradical

Ist Teil von

• Angewandte Chemie International Edition, 2021-03, Vol.60 (13), p.7002-7006

Auflage

International ed. in English

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The synthesis of robust high‐spin carbon radicals is an important topic in organic chemistry. Toward this end, several porphyrin‐stabilized radicals have been systematically explored. A singly naphthalene‐fused porphyrin radical was synthesized by a reaction sequence consisting of a Suzuki–Miyaura coupling of β‐borylated porphyrin with 2‐bromobenzaldehyde, addition of mesityl Grignard reagent, intramolecular Friedel–Crafts alkylation, and final oxidation with DDQ or tBuOK/O2. This strategy was also used to synthesize doubly naphthalene‐fused porphyrins and syn‐ and anti‐fused‐anthracene‐bridged porphyrin dimers. While singly naphthalene‐fused porphyrin radical has been shown to be a stable monoradical, doubly naphthalene‐fused porphyrins and anti‐fused‐anthracene‐bridged porphyrin dimers have been shown to be closed‐shell molecules. Finally, the syn‐dimer was characterized as a surprisingly stable radical (t1/2=28 days under ambient air and at 80 °C) that is storable for more than several months, despite its high‐spin triplet ground‐state carbon diradical. Naphthalene/anthracene‐fused porphyrins were synthesized by a Suzuki–Miyaura coupling and subsequent intramolecular Friedel–Crafts alkylation and oxidation. The structures of 3Ni, 6Ni, 9Ni, 11Ni, and 13Ni have been confirmed by X‐ray crystallographic analysis. 11Ni is characterized as a surprisingly stable radical (t1/2=28 days under ambient air and at 80 °C) that is storable for more than several months, despite its high‐spin triplet ground‐state carbon diradical.