Synthesis of aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO₂F₂)

• Xian-Lin Chen and
• Hua-Li Qin

Beilstein J. Org. Chem. 2023, 19, 901–908, doi:10.3762/bjoc.19.68

• activated intermediates for a variety of transformations [46][47][48][49][50][51][52][53][54][55][56][57][58]. Lately, we discovered the SO2F2-mediated transformation of primary alcohols to nitriles, involving an aldoxime sulfonyl ester intermediate (Scheme 2c) [59]. Drawing inspiration from these excellent

Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides

• Md Imran Hossain,
• Md Imdadul H. Khan,
• Seong Jong Kim and
• Hoang V. Le

Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47

• . Purification via column chromatography (ethyl acetate/hexanes) resulted in the aldoxime product. To a solution of the aldoxime (1 mmol) in DMF was added N-chlorosuccinimide and the mixture stirred for 18 h at rt. After the reaction was complete, as indicated by TLC, the reaction mixture was poured into water

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

• corresponding to the free iminoxyl radical, which indicates the reversibility of dimerization [53]. During the oxidation of pivalic aldoxime 1e by Ag2O, the formation of nitrile oxide 6e was observed, which then slowly dimerized to the corresponding furoxan 7e. The kinetics of the decomposition of dialkyl

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• amidoxime, ethanone oxime and aldoxime (VI, VII, VIII, R1 = p-pyridyl, Figure 1) as DNA photosensitizers. Based on our previous experimental results with o-, m- and p-pyridine oximes as carriers of the carboxylic [9] and sulfonic [11] ester conjugates, we proclaimed p-substituted pyridine ring as the most

• phenyl groups, bearing electron donating or withdrawing substituents, were synthesized and evaluated. Results and Discussion Synthesis All compounds were synthesized upon the reaction of the appropriate parent p-pyridine amidoxime 1 [58], ethanone oxime 14 [59] and aldoxime 21 [60] with the corresponding

• 8.1 to 10.7 ppm and for the benzyl derivative 15 at 6.63 ppm. In the case of aldoxime carbamates three reactions gave mixtures of inseparable Z-stereoisomers ≈10% along with the major E-stereoisomer (products 25–27). It has been noted in the literature the preferable E-conformation for oxime

Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective

• Yaroslav D. Boyko,
• Valentin S. Dorokhov,
• Alexey Yu. Sukhorukov and
• Sema L. Ioffe

Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220

• corresponding adduct 44 in 93% yield. Importantly, both stereoisomers obtained were oxime E,Z-isomers with the C-7 relative configuration being the same as in myrioneurinol. Subsequent deoxygenation and reduction of aldoxime followed by transformation of the malonate unit to the formyl group furnished

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• variety of aryl halides were converted to the corresponding phenols. Fu and co-workers employed pyridine-2-aldoxime (PAO, L7) as ligand and developed a Cu2O catalyzed hydroxylation protocol [33]. The reaction was carried out at 110 °C in water in the presence of n-Bu4NBr as phase transfer catalyst (Scheme

Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

• Sophie Letort,
• Sébastien Balieu,
• William Erb,
• Géraldine Gouhier and
• François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

• functionalization, Kubik et al. [75] described two routes to access β-CD derivatives monosubstituted on the primary rim with various nucleophiles. The first one is based on the monotosylation of one C-6 hydroxy, followed by a nucleophilic substitution with a substrate bearing an aldoxime group (pathway i, Scheme 4

• ); the second route starts from the same tosylated intermediate 18, substituted by an azide function, precursor of a triazole ring used to link the aldoxime moiety (pathway ii, Scheme 4). Following this second approach, Kubik et al. published new α-, β- and γ-CD derivatives functionalized with hydroxamic

• macromolecule. Efficiency of compounds 23a–i against chemical warfare agents: Amongst the derivatives 23a–i with the pyridine aldoxime linked to the CD by a triazole ring, compound 23a is the most interesting scavenger. To access more potent compounds, Kubik et al. later introduced two α-nucleophiles on A and D

Synthesis of trifluoromethyl-substituted pyrazolo[4,3-c]pyridines – sequential versus multicomponent reaction approach

• Barbara Palka,
• Angela Di Capua,
• Maurizio Anzini,
• Gyté Vilkauskaité,
• Algirdas Šačkus and
• Wolfgang Holzer

Beilstein J. Org. Chem. 2014, 10, 1759–1764, doi:10.3762/bjoc.10.183

• an alkyne 3 in the presence of a suitable catalytic system were not successful. However, after conversion of 2 into the corresponding aldoxime 9 the latter could be transformed into the N-oxides 7a and 7b by reaction with alkynes 3a and 3b, respectively, employing Pd(OAc)2 as the catalyst and under

A one-pot synthesis of 3-trifluoromethyl-2-isoxazolines from trifluoromethyl aldoxime

• Raoni S. B. Gonçalves,
• Michael Dos Santos,
• Guillaume Bernadat,
• Danièle Bonnet-Delpon and
• Benoit Crousse

Beilstein J. Org. Chem. 2013, 9, 2387–2394, doi:10.3762/bjoc.9.275

• -trifluoromethylisoxazoles were easily prepared from trifluoromethyl aldoxime 2 under mild conditions by using DIB as oxidant. Theoretical studies of the reactivity of trifluoroacetonitrile oxide 4 toward olefins and alkynes were carried out. The 3-trifluoromethyl-2-isoxazolines were ring-opened with NaBH4 and NiCl2 to

• yield the corresponding trifluoromethylated γ-amino alcohols. Keywords: aldoxime; amino alcohol; fluorine; isoxazole; isoxazoline; organo-fluorine; Introduction 2-Isoxazolines are five-membered heterocyclic compounds that have been widely applied in medicinal and organic chemistry. This nucleus is

• multistep procedure are described (Scheme 1) [25]. Initially, trifluoromethyl aldoxime 2 is halogenated to give a volatile trifluoroacetohydroxymoyl chloride or bromide 3, which is usually isolated in low yields. Reaction of intermediate 3 with a base provides trifluoroacetonitrile oxide 4, which can be

Aryl nitrile oxide cycloaddition reactions in the presence of pinacol boronic acid ester

• Sarah L. Harding,
• Sebastian M. Marcuccio and
• G. Paul Savage

Beilstein J. Org. Chem. 2012, 8, 606–612, doi:10.3762/bjoc.8.67

• dual functionality consisting of a nitrile oxide and a pinacolyl boronate ester was prepared by mild hypervalent iodine oxidation (diacetoxyiodobenzene) of the corresponding aldoxime, without decomposition of the boronate functionality. The nitrile oxide was trapped in situ with a variety of

• ) or generated in situ by dehydrohalogenation of a preformed hydroximoyl chloride. This is presumably to avoid the competing oxidative side reactions that would be expected at the boronate ester if the nitrile oxide were generated oxidatively from the aldoxime [32]. The same thermodynamic bias

• prepared from the corresponding boronic acid, via the bromide [33]. Reaction with 50% aqueous hydroxylamine gives the aldoxime 5 in good yield (Scheme 3). Only one geometric isomer of the aldoxime was observed in the 1H and 13C NMR spectra, and this was assigned as the Z isomer based on the 8.17 ppm

Highly efficient cyclosarin degradation mediated by a β-cyclodextrin derivative containing an oxime-derived substituent

• Michael Zengerle,
• Florian Brandhuber,
• Christian Schneider,
• Franz Worek,
• Georg Reiter and
• Stefan Kubik

Beilstein J. Org. Chem. 2011, 7, 1543–1554, doi:10.3762/bjoc.7.182

• substituents with an aldoxime or a ketoxime moiety along the narrow opening of the β-cyclodextrin cavity was synthesized, and the ability of these compounds to reduce the inhibitory effect of the neurotoxic organophosphonate cyclosarin on its key target, acetylcholinesterase, was assessed in vitro. All

• pyridine ring can most probably be attributed to the higher acidity of the aldoxime proton in pyridinium aldoximes, for example. For reference, the pKa of the aldoxime proton in 3-formylpyridine oxime amounts to 10.36 and that of the corresponding proton in the 1-methiodide of 3-formylpyridine oxime to

• 9.22. Correspondingly, the pKa of the aldoxime proton in 4-formylpyridine oxime (9.99) also decreases by more than one order of magnitude to 8.57 upon methylation of the ring nitrogen [46]. Thus, oximes on pyridinium rings are deprotonated more easily, which renders them more nucleophilic. The