23781-82-0Relevant articles and documents
Expansion of Azulenes as Nonbenzenoid Aromatic Compounds for C-H Activation: Rhodium- And Iridium-Catalyzed Oxidative Cyclization of Azulene Carboxylic Acids with Alkynes for the Synthesis of Azulenolactones and Benzoazulenes
Maeng, Chanyoung,Son, Jeong-Yu,Lee, Seung Cheol,Baek, Yonghyeon,Um, Kyusik,Han, Sang Hoon,Ko, Gi Hoon,Han, Gi Uk,Lee, Kyungsup,Lee, Kooyeon,Lee, Phil Ho
supporting information, p. 3824 - 3837 (2020/02/28)
Rhodium-catalyzed oxidative [4 + 2] cyclization reactions through the C-H activation of azulene carboxylic acids as nonbenzenoid aromatic compounds with symmetrical and unsymmetrical alkynes were developed under aerobic conditions, which produced azulenolactone derivatives with a wide substrate scope and excellent functional group tolerance. Interestingly, azulenic acids in reaction with alkynes underwent iridium-catalyzed [2 + 2 + 2] cyclization accompanied by decarboxylation to afford tetra(aryl)-substituted benzoazulene derivatives. The reactivity order for C-H activation reaction is greater toward azulene-6-carboxylic acid, azulene-1-carboxylic acid, and azulene-2-carboxylic acid. For the first time, the expansion of azulenes having directing group as nonbenzenoid aromatic compounds for C-H activation was successful, indicating that nonbenzenoid aromatic compounds can be used as good substrates for the C-H activation reaction. Therefore, the research area of C-H activation will certainly expand to nonbenzenoid aromatic compounds in future.
Gold-Catalyzed Direct Alkynylation of Azulenes
Székely, Anna,Péter, áron,Aradi, Klára,Tolnai, Gergely L.,Novák, Zoltán
supporting information, 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.
Syntheses and reactivity of meso-unsubstituted azuliporphyrins derived from 6-tert-butyl- and 6-phenylazulene
Lash, Timothy D.,El-Beck, Jessica A.,Ferrence, Gregory M.
, p. 8402 - 8415 (2008/03/12)
(Chemical Equation Presented) A series of six azuliporphyrins with substituents on the seven-membered ring were prepared by two different "3 + 1" routes from 6-tert-butyl- and 6-phenylazulene. The substituted azulenes can be converted into dialdehydes und
ARYLATION OF AZULENE
Nefedov, V. A.,German, N. A.,Lutsenko, A. I.,Nikishin, G. I.
, p. 154 - 162 (2007/10/02)
In the reaction of azulene with phenylhydrazine and an oxidizing agent (Cu(2+)) a mixture of 1-phenylazulene (28percent) with 2-, 4-, and 6-phenylazulenes (27percent in total) is formed; a series of para-substituted phenylazulenes and α-naphthylazulenes were obtained in a similar way.If p-nitrophenylhydrazine is used, selective arylation of azulene (at position 1) and also of dimethylaniline (at the ortho and para positions) occurs.An excess of the oxidizing agent (Cu(2+)) increases and an excess of the reducing agent (arylhydrazine) reduces the selectivity of arylation.Some of the obtained arylazulenes can be used as dichroic coloring additives for liquid crystals.
