Gold‐Catalyzed Intramolecular Alkyne Cycloisomerization Cascade: Direct Synthesis of Aryl‐Annulated[<i>a</i>]carbazoles from Aniline‐Substituted Diethynylarenes

Hirano, Kimio; Inaba, Yusuke; Watanabe, Toshiaki; Oishi, Shinya; Fujii, Nobutaka; Ohno, Hiroaki

doi:10.1002/adsc.200900880

Cited by 130 publications

(44 citation statements)

References 40 publications

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“…The same authors found [33] that the action of the base on 2,3-dialkynylpyridine 20 having the ortho aminophenyl substituent at the triple bond promotes another cascade transformation including the consecutive 5-endo-dig/5-exo-dig cyclizations with the pyrrole and fulvene ring closure (Scheme 14). At the same time in the presence of catalytic amounts of NaAuCl 4 ·2Н 2 O compound 20 is converted into the pyridocarbazole 22 [33,34].…”

Section: T-buomentioning

confidence: 88%

“…Under analogous conditions the N-methyl and N-Boc derivatives of compounds 23 are easily cyclized into N-substituted benzocarbazoles. High yields of the cyclization products are also observed when the 2,3-dialkynyl derivatives of thiophene and furan are used as substrates [33,34].…”

Section: Scheme 16mentioning

confidence: 88%

“…At the same time in the presence of catalytic amounts of NaAuCl 4 ·2Н 2 O compound 20 is converted into the pyridocarbazole 22 [33,34]. Other ortho dialkynylarenes such as compound 23 also enter similar cyclization (Scheme 15) [34].…”

Section: T-buomentioning

confidence: 97%

“…It should be noted that in 2010, due to reinvestigations of the above reaction, Japanese chemists concluded that its products are not the carbazoles 16 or the indoles 17, but the pyrido[1,2-a]indoles 18 and 19 (Scheme 12) [33]. …”

Section: Scheme 11mentioning

confidence: 99%

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Nucleophilic cyclizations of enediynes as a method for polynuclear heterocycle synthesis

Gulevskaya

Tyaglivy

2012

Chem Heterocycl Comp

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In this review, data on the heterocyclization of enediynes, initiated by attack of an external anionic nucleophile or a nucleophilic group present in the molecule at the C≡C bond of the enediyne, are summarized.Today, the chemistry of acetylenes is experiencing its new birth. Effective methods for the synthesis of acetylenes based on the transition metal catalyzed cross-coupling of organic halides and triflates with 1-alkynes [1], alkynylboronic acids [2], alkynylstannanes [3] have been developed. The acetylenes that became accessible are used successfully for the synthesis of various carbo-and heterocyclic compounds [4][5][6][7][8][9]. In the general case addition of a nucleophilic group to a carbon-carbon triple bond leads to a hetero-ring closure according to Scheme 1, and here the formation both of endo-dig cyclization products and of heterocycles with an exocyclic C=C bond (exo-dig cyclization) is possible: exo-digR Nu X R Nu = NH, O, S, etc.; X = H or other leaving groupThe interest of researchers in the chemistry of acetylenes is also due to the discovery of a whole family of antibiotics containing a cis-3-hexene-1,5-diyne fragment in their structures and therefore called enediyne antibiotics [10][11][12][13][14]. When heated or irradiated the enediynes undergo a Bergman cyclization; they close to 1,4-arynes, which are converted in the presence of suitable donors of hydrogen atoms or other free radicals into the corresponding arenes (Scheme 2) [15]. It is supposed that the mechanism of biological action of enediyne antibiotics is based on this rather exotic transformation. At the biological level the role of hydrogen atom donor is played by a DNA molecule that leads to its destruction. This determines not only the antibacterial, but also the antiviral and anticancer activity of the enediyne antibiotics.

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Section: T-buomentioning

confidence: 88%

Section: Scheme 16mentioning

confidence: 88%