β,β‐Diborylated Subporphyrinato Boron(III) Complexes as Useful Synthetic Precursors |
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Authors: | Masaaki Kitano Yasuhiro Okuda Dr Eiji Tsurumaki Dr Takayuki Tanaka Prof Dr Hideki Yorimitsu Prof Dr Atsuhiro Osuka |
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Institution: | 1. Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo‐ku, Kyoto 606‐8502 (Japan);2. ACT‐C (Japan) Science and Technology Agency (Japan) |
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Abstract: | Iridium‐catalyzed borylation of B‐aryl meso‐free subporphyrinato boron(III) complexes (hereinafter referred to simply as subporphyrins) with bis(pinacolato)diboron gave 2,13‐diborylated subporphyrins regioselectively, which served as promising synthetic precursors for 2,13‐diarylated subporphyrins and doubly β‐to‐β 1,3‐butadiyne‐bridged subporphyrin dimers. 2,13‐Diarylated subporphyrins display perturbed absorption spectra, depending upon the β‐aryl substituents. Doubly 1,3‐butadiyne‐bridged syn and anti subporphyrin dimers thus prepared exhibit differently altered absorption spectra with split Soret‐like bands, which have been accounted for in terms of exciton coupling. |
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Keywords: | borylation cross‐coupling exciton coupling porphyrinoids subporphyrins |
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