Polyfunctionalized 3-nitropyridine derivatives by [4 + 2] cycloadditions of 4-nitro-3-phenylisoxazole-5-carboxylates with enamines: applications and limits

Nesi, Rodolfo; Giomi, Donatella; Papaleo, S.; Turchi, Stefania

doi:10.1021/jo00039a037

Cited by 24 publications

(7 citation statements)

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“…Previously reported approaches to 4 include the reaction of aromatic α,β-unsaturated aldehydes with dinitrogen trioxide [11–12], the nitration of 3-phenyl-isoxazole [13–14], and the hydrolysis of methyl 4-nitro-3-phenyl-5-carboxylate, obtained by reaction of α-nitroacetophenone oxime and methoxalyl chloride [15]. …”

Section: Resultsmentioning

confidence: 99%

A surprising new route to 4-nitro-3-phenylisoxazole

Hopf

Mourad²,

Jones

2010

Beilstein J. Org. Chem.

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Section: Resultsmentioning

confidence: 99%

A surprising new route to 4-nitro-3-phenylisoxazole

Hopf

Mourad²,

Jones

2010

Beilstein J. Org. Chem.

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“…However, the most common methods for ArN→O synthesis such as oxidation with meta ‐chloroperoxybenzoic acid ( m CPBA) (laboratory scale) or hydrogen peroxide (industrial scale) are hazardous and possess some serious limitations (Vörös et al ., 2014). Also, ArN→O can be prepared by various rearrangements and ring‐closing reactions (Chucholowski and Uhlendorf, 1990; Nesi et al ., 1992); nevertheless, the existing organic chemistry methods are not able to fully address existing demands and, usually, they do not match the increasing environmental requirements. Therefore, the establishment of biocatalytic methods for ArN→O production seems a promising alternative that can offer selectivity and sustainability.…”

Section: Introductionmentioning

confidence: 99%

An efficient and regioselective biocatalytic synthesis of aromatic N‐oxides by using a soluble di‐iron monooxygenase PmlABCDEF produced in the Pseudomonas species

Petkevičius

Vaitekūnas

Gasparavičiūtė

et al. 2021

Microbial Biotechnology

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Here, we present an improved whole-cell biocatalysis system for the synthesis of heteroaromatic N-oxides based on the production of a soluble di-iron monooxygenase PmlABCDEF in Pseudomonas sp. MIL9 and Pseudomonas putida KT2440. The presented biocatalysis system performs under environmentally benign conditions, features a straightforward and inexpensive procedure and possesses a high substrate conversion and product yield. The capacity of gram-scale production was reached in the simple shake-flask cultivation. The template substrates (pyridine, pyrazine, 2aminopyrimidine) have been converted into pyridine-1-oxide, pyrazine-1-oxide and 2-aminopyrimidine-1oxide in product titres of 18.0, 19.1 and 18.3 g l -1 , respectively. To our knowledge, this is the highest reported productivity of aromatic N-oxides using biocatalysis methods. Moreover, comparing to the chemical method of aromatic N-oxides synthesis based on meta-chloroperoxybenzoic acid, the developed approach is applicable for a regioselective oxidation that is an additional advantageous option in the preparation of the anticipated N-oxides.

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“…The alternatives include condensation reactions, various ring transformations, rearrangements and cycloadditions. [13,14] These reactions, however, are relatively unspecific and often complicated. Most recently, Mo/ P-catalyzed oxidation [15] and 2,2,2-trifluoroacetophenone/H 2 O 2 based oxidation [16] have been introduced as promising new methods.…”

Section: Introductionmentioning

confidence: 99%

“…The main drawback of these methods is a possible product contamination with potentially hazardous metals. The alternatives include condensation reactions, various ring transformations, rearrangements and cycloadditions . These reactions, however, are relatively unspecific and often complicated.…”

Section: Introductionmentioning

confidence: 99%

A Biocatalytic Synthesis of HeteroaromaticN‐Oxides by Whole Cells ofEscherichia coliExpressing the Multicomponent, Soluble Di‐Iron Monooxygenase (SDIMO) PmlABCDEF

et al. 2019

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Aromatic N-oxides (ArNÀOX) are desirable biologically active compounds with a potential for application in pharmacy and agriculture industries. As biocatalysis is making a great impact in organic synthesis, there is still a lack of efficient and convenient enzyme-based techniques for the production of aromatic N-oxides. In this study, a recombinant soluble di-iron monooxygenase (SDIMO) PmlABCDEF overexpressed in Escherichia coli was showed to produce various aromatic N-oxides. Out of 98 tested Nheterocycles, seventy were converted to the corresponding N-oxides without any side oxidation products. This whole-cell biocatalyst showed a high activity towards pyridines, pyrazines, and pyrimidines. It was also capable of oxidizing bulky N-heterocycles with two or even three aromatic rings. Being entirely biocatalytic, our approach provides an environmentally friendly and mild method for the production of aromatic N-oxides avoiding the use of strong oxidants, organometallic catalysts, undesirable solvents, or other environment unfriendly reagents.

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Polyfunctionalized 3-nitropyridine derivatives by [4 + 2] cycloadditions of 4-nitro-3-phenylisoxazole-5-carboxylates with enamines: applications and limits

Cited by 24 publications

References 1 publication

A surprising new route to 4-nitro-3-phenylisoxazole

A surprising new route to 4-nitro-3-phenylisoxazole

An efficient and regioselective biocatalytic synthesis of aromatic N‐oxides by using a soluble di‐iron monooxygenase PmlABCDEF produced in the Pseudomonas species

A Biocatalytic Synthesis of HeteroaromaticN‐Oxides by Whole Cells ofEscherichia coliExpressing the Multicomponent, Soluble Di‐Iron Monooxygenase (SDIMO) PmlABCDEF

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