Nonbenzenoid aromatic systems. XII. Synthesis of 2-, 3-, and 6-substituted 2-(1-azulyl)ethanols and their tosylate esters

Biazulene diimides: a new building block for organic electronic materials

“…Compound 9 was prepared in 59% yield by a Suzuki cross-coupling reaction of 7 with 2-bromoazulene 8 . 18 The intermediate 9 then underwent a similar self-coupling reaction to 1 , giving the key precursor 10 in 94% yield. Hydrolysis of 10 gave acid 11 , which was not purified and directly underwent a condensation reaction in refluxing acetic anhydride, affording dianhydride 12 with an overall two-step yield of 72%.…”

Synthesis of 2‐Azulenyl‐1,1,4,4‐tetracyano‐3‐ferrocenyl‐1,3‐butadienes by [2+2] Cycloaddition of (Ferrocenylethynyl)azulenes with Tetracyanoethylene

“…[16] The high yield of product 13 should be due to the electron-withdrawing nature of the 1,3-diethoxycarbonyl groups on the azulene ring, which should increase the reactivity toward oxidative addition of the palladium catalyst. The cross-coupling reaction of 6-bromoazulene (6) [17] with ethynylferrocene in the presence of the palladium-catalyst afforded 6-(ferrocenylethynyl)azulene (14) in 99 % yield. Similar to the reactions described above, Sonogashira-Hagihara reaction of ethynylferrocene with 6bromoazulene derivatives 8 [4] and 9 [18] gave the corresponding cross-coupled products 15 and 16 in 97 and 95 % yield, respectively (Scheme 4).…”

Crystal structure of diethyl 2-amino-6-[(thiophen-3-yl)ethynyl]azulene-1,3-dicarboxylate

“…For the synthesis of the title compound concerning the azulene-derived starting material, see: McDonald et al (1976). For the background of this work and for the synthesis of related compounds, see: Xia et al (2014); Fö rster et al (2012).…”