Synthesis and Properties of Fluoroazulenes. II. Electrophilic Fluorination of Azulenes with<i>N</i>-Fluoro Reagents
作者:Tetsuya Ueno、Haruhiko Toda、Masafumi Yasunami、Masaaki Yoshifuji
DOI:10.1246/bcsj.69.1645
日期:1996.6
3-difluoroazulenes were synthesized for the first time by the electrophilic fluorination of azulenes with N-fluoro reagents. Selective preparation of 1-fluoroazulenes were performed by the fluorination of methyl azulene-1-carboxylates, followed by demethoxycarbonylation in 100% H3PO4. 2-Substituted azulenes were fluorinated in higher yields. In the 1H NMR of 1-fluoroazulene, long-range JFH values were
1-氟-和1,3-二氟-和1,3-二氟-和1-二氟-和1,3-二氟- azulenes 是第一次通过用N-氟试剂对azulenes 进行亲电氟化来合成。1-氟丁烯的选择性制备是通过甲基 azulene-1-carboxylates 的氟化,然后在 100% H3PO4 中脱甲氧基羰基化来进行的。2-取代的芘以更高的产率被氟化。在 1-氟芴的 1H NMR 中,与 1-氟萘相比,在 H-2 和 H-8 处未观察到长程 JFH 值。由于所谓的 +Iπ 效应,1-氟原子会导致薁的可见光吸收发生显着的红移。