275-51-4Relevant articles and documents
A Convenient Synthesis of Azulene
Langhals, Heinz,Ebersp?cher, Moritz
, p. 1862 - 1866 (2018)
An improved and scalable synthesis of azulene has been developed by the application of pyrrolidine as a reagent and continuous steam distillation and extraction for workup. Applications for the coloration of perfluorinated media and silicones were demonstrated.
Generation of hexahydroazulenes
Kr?mer, Guido,Detert, Heiner,Meier, Herbert
, p. 4810 - 4812 (2009)
(Z)-Cyclodec-1-en-6-yne (3) generates three conjugated hexahydroazulenes 3→1k→1c, 1? under FVP conditions, whereas flash vacuum pyrolysis (FVP) of cyclodecyne (2) leads to 1,2,9-decatriene (9). We attribute the different thermal behavior of 2 (ring opening) and 3 (ring closure) to different transannular interactions. Altogether 22 constitutional isomers of hexahydroazulene should exist; three new isomers (1k, 1?, and 1m) are presented here, ten were described earlier, but the reinvestigation of the dehydration route of bicyclic alcohol 11 showed that one of the ten structures has to be revised.
Preparation of azulenyllithium and magnesium reagents utilizing halogen-metal exchange reaction of several iodoazulenes with organolithium or magnesium ate complex
Ito, Shunji,Kubo, Takahiro,Morita, Noboru,Matsui, Yoshitaka,Watanabe, Toshiyuki,Ohta, Akira,Fujimori, Kunihide,Murafuji, Toshihiro,Sugihara, Yoshikazu,Tajiri, Akio
, p. 2891 - 2894 (2004)
Preparation of several azulenyllithium and magnesium reagents was achieved by the halogen-metal exchange reaction of iodoazulenes with n-butyllithium or lithium tri(n-butyl)magnesate at low temperature and the synthetic application of the reagents was explored.
Blue Amino Acids Derived from Azulen-1-ylboronic Acid Pinacol Ester via the Petasis Reaction
Murafuji, Toshihiro,Tasaki, Yusuke,Fujinaga, Masayuki,Tao, Keisuke,Kamijo, Shin,Ishiguro, Katsuya
, p. 1037 - 1042 (2017)
Azulen-1-ylboronic acid pinacol ester undergoes a three-component Petasis reaction with amines and glyoxylic acid hydrate to give azulenylglycine derivatives in good yields. The progress of the reaction is indicated by a characteristic color change from violet to blue due to the altered π-conjugation of the azulene chromophore. The azulenylboronic ester is more reactive than its phenyl counterpart and even 2-styryl- and 2-thienylboronic pinacol esters, which have a strong electron-donating organyl group on boron. These results reflect the unique π-electron system of non-alternant azulene.
Coupling reaction of azulenyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolanes with haloazulenes
Kurotobi, Kei,Tabata, Hiroshi,Miyauchi, Masato,Murafuji, Toshihiro,Sugihara, Yoshikazu
, p. 1013 - 1016 (2002)
In order to study the physicochemical properties of azulene oligomers, the synthesis and a coupling reaction of 2-(2-amino-1,3-bisethoxycarbonyl-6-azulenyl)-4,4,5,5-tetramethyl-1,3,2- dioxaborolane (1) and 2-(2-azulenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2) were examined.
Reaction of azulenes with 1-trifluoromethanesulfonylpyridinium trifluoromethanesulfonate (TPT) and synthesis of the parent azulene.
Ito, Shunji,Yokoyama, Ryuji,Okujima, Tetsuo,Terazono, Tomomi,Kubo, Takahiro,Tajiri, Akio,Watanabe, Masataka,Morita, Noboru
, p. 1947 - 1952 (2003)
2-Azulenyl trifluoromethanesulfonate was prepared by the reaction of 2-hydroxyazulene with trifluoromethanesulfonic anhydride in the presence of triethylamine as a base. Under the use of pyridine, 1-trifluoromethanesulfonylpyridinium trifluoromethanesulfonate further reacted with 2-azulenyl trifluoromethanesulfonate to give 1-(1-trifluoromethanesulfonyl-1,4-dihydropyridin-4-yl)azulenyl trifluoromethanesulfonate. Moreover, we found that azulenes also reacted with 1-trifluoromethanesulfonylpyridinium trifluoromethanesulfonate to give 4-(1-azulenyl)-1,4-dihydropyridine derivatives and 6-(1-azulenyl)-1-trifluoromethanesulfonyl-1-aza-hexa-1,3,5-triene depending on the reaction conditions. 2-Azulenyl trifluoromethanesulfonate was converted finally into the parent azulene in excellent yield by palladium-catalyzed reduction using formic acid as a reducing reagent.
UNE NOUVELLE VOIE D'ACCES AU SQUELETTE DE L'AZULENE
Jost, P.,Chaquin, P.,Kossanyi, J.
, p. 465 - 466 (1980)
Irradiation of 2-allylcycloheptanone 3 forms a mixture of two oxetans, 4 and 5, in high yields. 11-Oxa tricyclo 1,9.0> undecane 5, which constitutes the 9/11 of the photoproducts, is decomposed thermally into a mixture of hydroazulene derivatives.Dehydrogenation of this mixture over palladium on alumina forms azulene.
Gold-Catalyzed Direct Alkynylation of Azulenes
Székely, Anna,Péter, áron,Aradi, Klára,Tolnai, Gergely L.,Novák, Zoltán
, p. 954 - 957 (2017/02/26)
A novel catalytic method for the direct C-H alkynylation of azulenes is developed. The gold catalyzed functionalization of this special carbacycle is achieved with hypervalent iodonium reagent TIPS-EBX under mild reaction conditions. With the aid of the developed procedure, several TIPS alkynylated azulene derivatives were synthesized bearing important functional groups for further functionalization.
Bicyclo[6.3.0]undeca-1(11),2,4,6,8-pentaen-10-ylidene: An Aromatic Carbene with Ambiphilic Properties
Ishikawa, Hiroyuki,Nishida, Jun-Ichi,Jones, John W.,Scott, Lawrence T.,Kawase, Takeshi
, p. 1073 - 1077 (2017/07/25)
The title carbene (4) was generated as a highly reactive species in solution by photoirradiation of 10-diazobicyclo[6.3.0]undecapentaene (5) using a high-pressure mercury lamp. Carbene 4 reacts with benzene to afford two isomeric adducts, 10-phenylbicyclo[6.3.0]undecapentaene (10) and tricyclo[9.3.03, 10.0]heptadeca-1,3(10),4,6,8,12,14,16-octaene (11). The reactivity toward benzene is a characteristic of an electrophilic aromatic carbene analogous to cyclopentadienylidene 1. In contrast, the reaction of 4 with methanol produces 7-methoxybicyclo[6.3.0]undeca-1,3,5,8,10-pentaene (15). When [D1]methanol was employed as a reactant, the 10-deuterated analogue was formed. The results clearly indicate the formation of bicyclo[6.3.0]undecapentaenyl cation (7) as a novel 10 π-electronic compound by protonation of 4. Theoretical calculations indicate that the 2- and 7-positions of the cation have the largest positive charge in the cation. Moreover, the carbene was generated in the presence of tert-butyl hydroperoxide in aqueous tetrahydrofuran to afford azulene through oxidation of 7, followed by decarbonylation. The nucleophilic property of carbene 3 is similar to that of cycloheptatrienylidene 2. Thus, 4 can be regarded as a novel ambiphilic aromatic carbene.
Azulenylcarbene and Naphthylcarbene Isomerizations. Falling Solid Flash Vacuum Pyrolysis
Kvaskoff, David,Becker, Jürgen,Wentrup, Curt
, p. 5030 - 5034 (2015/05/27)
1-Azulenylcarbene 18 has been generated from 5-(1-azulenyl)tetrazole and the sodium salt of azulene-1-carbaldehyde tosylhydrazone using the falling solid flash vacuum pyrolysis (FS-FVP) method. The principal products, which are also formed from both 1- and 2-naphthylcarbenes, cyclobuta[de]naphthalene 6, cyclopenta[cd]indene 16, and benzofulvenallene 17, are explained in terms of two reaction paths, (a) a rearrangement to benzofulvenyl-7-carbene 13 and (b) a rearrangement to 1-naphthylcarbene 1. Moreover, 16 is also formed from 2-azulenylcarbene 30, thereby indicating the occurrence of a 2-azulenylcarbene-1-azulenylcarbene rearrangement. The reaction mechanisms are supported by density functional theory calculations at the B3LYP/6-31G?? level, which indicate that all the rearrangements have activation barriers of 35 kcal/mol, thus making them readily achievable under FVP conditions. Chemical Presented.
