Advances in the Chichibabin Reaction

Mcgill, Charles K.; Rappa, Angela

doi:10.1016/s0065-2725(08)60261-5

Cited by 105 publications

(45 citation statements)

References 114 publications

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“…Compound 2 can exist in several tautomeric forms. [7,8] Similar structures were reported such as Aspernigrin A (6-benzyl-4-hydroxy-nicotinamide). [9] The chelation of 4-OH with 7-NH could explain the values of their chemical shifts in 1 H NMR spectrum ( Table 2).…”

Section: Introductionsupporting

confidence: 57%

Structure elucidation and NMR assignments for two amide alkaloids from a Mangrove endophytic Fungus (No. ZZF‐22)

Chen

Shao

Zhong-jing

et al. 2008

Magnetic Reson in Chemistry

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The structure elucidations and complete (1)H and (13)C NMR assignments are reported for two new natural products: 3-benzylidene-8,8a-dihydroxy-2-methyl-hexahydro-pyrrolo[1,2-a]pyrazine-1,4-dione(1) and 4-hydroxy-6-(hydroxy-phenyl-methyl)-N-(3-methyl-butyryl)-nicotinamide (2). Both of these secondary metabolites were isolated from the fermentation medium of a Mangrove endophytic fungus. High resolution electron impact mass spectrometry (HREIMS), FT-IR Spectroscopy and NMR experiments including gCOSY, gHMQC, gHMBC and NOE were used for determination of the structures and assignments of the amide alkaloids.

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Section: Introductionsupporting

confidence: 57%

Structure elucidation and NMR assignments for two amide alkaloids from a Mangrove endophytic Fungus (No. ZZF‐22)

Chen

Shao

Zhong-jing

et al. 2008

Magnetic Reson in Chemistry

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“…26 Secondly, for the reactions that take place at or below room temperature, the OCF 3 group is introduced exclusively to the α′-position. 37–39 Since α- and α′-carbon of pyridines are metabolically labile sites, incorporation of an electron withdrawing OCF 3 group to the α′-position could improve their metabolic stability. 40,41 If the α′-position is blocked, product of γ-OCF 3 pyridine is formed instead ( 2g and 2h ).…”

Section: Resultsmentioning

confidence: 99%

Access to a new class of synthetic building blocks via trifluoromethoxylation of pyridines and pyrimidines

Feng

Lee

et al. 2016

Chem. Sci.

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Since the first synthesis of trifluoromethyl ethers in 1935, the trifluoromethoxy (OCF3) group has made a remarkable impact in medicinal, agrochemical, and materials science research. However, our inability to facilely incorporate the OCF3 group into molecules, especially heteroaromatics, has limited its potential across a broad spectrum of technological applications. Herein, we report a scalable and operationally simple protocol for regioselective trifluoromethoxylation of a wide range of functionalized pyridines and pyrimidines under mild reaction conditions. The trifluoromethoxylated products are useful scaffolds that can be further elaborated by amidation and palladium-catalysed cross coupling reactions. Mechanistic studies suggest that a radical O-trifluoromethylation followed by the OCF3-migration reaction pathway is operable. Given the unique properties of the OCF3 group and the ubiquity of pyridine and pyrimidine in biologically active molecules and functional materials, trifluoromethoxylated pyridines and pyrimidines could serve as valuable building blocks for the discovery and development of new drugs, agrochemicals, and materials.

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“…13 In the last few years, we have been pursuing investigations on the regiochemistry reaction of different nucleophiles with perhalogenated compounds. 15 Aromatic nucleophilic substitution reactions proceed via the AE-mechanism; 4-6 however, S RN1 -, [16][17][18] EA- [19][20][21] and S N (ANRORC)-22 mechanisms are also observed. The regioselectivity of nucleophilic substitution in this process was explained by the high nucleophilicity of the secondary or primary amino groups and by the activating influence of pyridine ring nitrogen that significantly activates the ortho and para sites to itself.…”

Section: Introductionmentioning

confidence: 99%

Regiochemistry of nucleophilic substitution of pentachloropyridine with N and O bidentate nucleophiles

2015

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Site reactivity of some enol-imines derived from N-aryl formamides with pentachloropyridine under basic conditions in dry CH 3 CN was investigated. The aromatic nucleophilic substitution of pentachloropyridine with enol-imines occurs at the 4-position of pyridine ring by both oxygen and nitrogen site of enol-imines.Nucleophilic attack by the oxygen of enol-imine gave corresponding oximino compounds as a mixture of E-and Z-isomers. In contrast, nucleophilic attack by the nitrogen of enol-imine gave the unexpected N,Ndi-substituted aryl compounds. The structures of all the compounds were confirmed by IR, 1 H NMR, 13 C NMR and 19 F NMR spectroscopy as well as elemental analysis and X-ray crystallography. Results and discussion Synthesis of precursor formamide compoundsSeveral papers have reported the preparation of these important compounds. [30][31][32] In this paper, we have established a new method for the synthesis of these compounds in a very short reaction time with high yields. The reaction of the aromatic

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Advances in the Chichibabin Reaction

Cited by 105 publications

References 114 publications

Structure elucidation and NMR assignments for two amide alkaloids from a Mangrove endophytic Fungus (No. ZZF‐22)

Structure elucidation and NMR assignments for two amide alkaloids from a Mangrove endophytic Fungus (No. ZZF‐22)

Access to a new class of synthetic building blocks via trifluoromethoxylation of pyridines and pyrimidines

Regiochemistry of nucleophilic substitution of pentachloropyridine with N and O bidentate nucleophiles

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