Aspects of heterocyclisation reactions mediated by nucleophilic interaction of aromatic nitro groups with ortho heterocumulene side chains

Duffy, Kevin J.; Tennant, G.; Wallis, Christopher J.; Weaver, George W.

doi:10.3998/ark.5550190.0003.308

Cited by 7 publications

(2 citation statements)

References 5 publications

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“…Thus, we were unable to find conditions for the formation of metallocarbenes from compounds 1 that undergo formal aromatic CH insertion. This is consistent with the fact that all diazo compounds containing an imidazole moiety studied to date easily undergo Wolff rearrangement under catalytic, photolytic, and thermal conditions, and reactions characteristic of metallocarbenes from such diazo compounds have not been published. − …”

Section: Resultssupporting

confidence: 75%

Cyclocondensation of 2-(α-Diazoacyl)-2H-azirines with Amidines in Diazo Synthesis of Functionalized Naphtho[1,2-d]imidazoles

Zanakhov,

Galenko,

Novikov

et al. 2024

J. Org. Chem.

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A diazo approach toward functionalized naphtho-[1,2-d]imidazole derivatives has been developed. It involved a new reaction of arylamidines with 2-(α-diazoacyl)-2H-azirines giving 5aryl-4-(α-diazoacyl)-1H-imidazoles under mild conditions in good yields. The mechanism of annulation of azirines with amidines is discussed based on DFT calculations. The reaction proceeds in an unusual manner by cleavage of the azirine C−C bond, allowing for the transfer of the aryl substituent from the arylamidine to the proper position of the key intermediate of naphtho[1,2-d]imidazole synthesis. Under thermolysis conditions, 5-aryl-4-(α-diazoacyl)-1Himidazoles undergo Wolff rearrangement followed by the selective 6π-cyclization of transient ketene to form 3H-naphtho[1,2-d]imidazoles bearing various substituents in the positions 2,3,4,5,7,8,9.Additionally, variation of the substituents at position 5 of naphtho[1,2-d]imidazoles is possible through the formation of triflates and subsequent cross-coupling reactions. One more heterocyclic pharmacophoric skeleton, 3H-furo[3′,2':3,4]naphtho [1,2-d]imidazole, was easily constructed from methyl 5-hydroxy-3H-naphtho[1,2-d]imidazole-4-carboxylates in a one-pot mode using O-alkylation with phenacyl bromides followed by base-induced intramolecular acyl substitution at room temperature with high yields.

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Section: Resultssupporting

confidence: 75%

Cyclocondensation of 2-(α-Diazoacyl)-2H-azirines with Amidines in Diazo Synthesis of Functionalized Naphtho[1,2-d]imidazoles

Zanakhov,

Galenko,

Novikov

et al. 2024

J. Org. Chem.

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“…Duffy and co-workers described the preparation of unusual 4 H -imidazo[4,5- c ]isoxazole 84 from diazo compound 83 which, in turn, was obtained via the coupling of acid chloride 81 with ethyl diazoacetate 82 [ 49 ]. On heating, 83 underwent the Wolff rearrangement to give ketene 17B, which cyclized to form zwitterionic intermediate 17C .…”

Section: Azoles With Two Heteroatomsmentioning

confidence: 99%

Diazocarbonyl and Related Compounds in the Synthesis of Azoles

et al. 2021

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Diazocarbonyl compounds have found numerous applications in many areas of chemistry. Among the most developed fields of diazo chemistry is the preparation of azoles from diazo compounds. This approach represents a useful alternative to more conventional methods of the synthesis of azoles. A comprehensive review on the preparation of various azoles (oxazoles, thiazoles, imidazoles, pyrazoles, triazoles, and tetrazoles) from diazocarbonyl and related compounds is presented for the first time along with discussion of advantages and disadvantages of «diazo» approaches to azoles.

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2010

Handbook of Heterocyclic Chemistry

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Aspects of heterocyclisation reactions mediated by nucleophilic interaction of aromatic nitro groups with ortho heterocumulene side chains

Cited by 7 publications

References 5 publications

Cyclocondensation of 2-(α-Diazoacyl)-2H-azirines with Amidines in Diazo Synthesis of Functionalized Naphtho[1,2-d]imidazoles

Cyclocondensation of 2-(α-Diazoacyl)-2H-azirines with Amidines in Diazo Synthesis of Functionalized Naphtho[1,2-d]imidazoles

Diazocarbonyl and Related Compounds in the Synthesis of Azoles

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