Nitrile Function Research Articles

Unsymmetrical α,ω-Difunctionalized Long-Chain Compounds via Full Molecular Incorporation of Fatty Acids

α,ω-Difunctionalized long-chain compounds A-(CH2)n-B are valuable intermediates and monomers. Unsymmetrical compounds with two different functional groups (A ≠ B) are, however, only accessible by multistep traditional organic syntheses to date. We report on their generation in a single step by isomerizing alkoxycarbonylations of the double bond deep in the chain of oleic derivatives. The compatibility with amide, nitrile and imide functionalities in the substrate allows for the formation with high linear selectivities (ca. 90%) and conversions (70 to 96%) of unsymmetric diesters, ester–amides, ester-nitriles and ester-(N-imides) in which these functional groups are terminally attached to a ≥ 17 methylene unit chain. These products further provide access to carboxylic acid-esters, alcohol-esters and amino-esters, and polymers from these AB-monomers. Undesired transesterifications that scramble the A and B functionalities are suppressed completely (<0.1%) by the utilization of a Pd(II) catalyst precursor devoid of acid additives in the presence of amine base.

The synthesis and properties of 6-trifluoromethyl-substituted thiopyrano[3,4-d]isoxazole derivatives

The first representatives of the novel 4,7а-dihydro-3аН-thiopyrano[3,4-d]isoxazole heterocyclic system, containing an ester, carboxyl, or hydroxymethyl group at position 3 and a trifluoromethyl group at position 6 were obtained by [3+2] cycloaddition reaction of ethyl cyanocarboxylate N-oxide and 6-trifluoromethyl-2Н-thiopyran, followed by further transformations of the ethyl 6-trifluoromethyl-4,7а-dihydro-3аН-thiopyrano[3,4-d]isoxazole-3-carboxylate intermediate. The cleavage of the isoxazoline ring of the obtained compounds led to the formation of 6-trifluoromethyl-2Н-thiopyran derivatives with nitrile or carbonyl-containing functionality at position 3. Transformations of the thiopyran moiety in 4,7а-dihydro-3аН-thiopyrano[3,4-d]isoxazole were studied for the case of Pummerer reaction product with oxidized sulfur atom, ethyl 6-trifluoromethyl-4,7а-dihydro-3аН-thiopyrano[3,4-d]isoxazole-3-carboxylate 5-oxide, which was converted to ethyl 6-trifluoromethyl-4Н-thiopyrano[3,4-d]isoxazole-3-carboxylate.

Studies on the Chemical Transformations of 6‐Methylchromone‐3‐carbonitrile under Nucleophilic Conditions

The chemical reactivity of 6‐methylchromone‐3‐carbonitrile (1) was studied towards some nucleophilic reagents. Reaction of carbonitrile 1 with malononitrile dimer and N′‐[(4‐methoxyphenyl)methylidene]‐2‐cyanoacetohydrazide (5) gave the unexpected chromeno[4,3‐b]pyridine 2 and benzoxocine‐3‐carbohydrazide 6, respectively. Reaction of carbonitrile 1 with 3‐amino‐1,2,4‐triazole, 2‐aminobenzimidazole, 7‐chloro‐4‐hydrazinoquinoline and 3‐hydrazino‐5,6‐diphenyl‐1,2,4‐triazine proceeds via γ‐pyrone ring opening followed by cycloaddition onto the nitrile function leading to a variety of heterocyclic systems. Structures of the new synthesized products were deduced on the basis of their analytical and spectral data.

Cross metathesis of bio-sourced fatty nitriles with acrylonitrile

We report the cross metathesis of two olefinic partners containing different types of nitrile functionality. Thus, cross metathesis of fatty nitriles with acrylonitrile have been achieved with olefin metathesis ruthenium catalysts. 10-Undecenenitrile provides 2-dodecenedinitrile with a high turnover number of 13,280 in the green solvent, diethyl carbonate. Cross metathesis with the internal carbon–carbon double bond of oleonitrile gave the expected products, and the cleavage of the internal double bond proved to be more difficult probably owing to faster catalyst decomposition.

Synthesis, structural analysis and antitumor activity of novel 17α-picolyl and 17(E)-picolinylidene A-modified androstane derivatives

The heterocyclic ring at C-17 position of the androstane compounds plays an important role in biological activity. The aim of the present study was to synthesize and evaluate potential antitumor activity of different A-modified 17α-picolyl and 17(E)-picolinylidene androstane derivatives. In several synthetic steps, novel derivatives bearing the hydroximino, nitrile or lactame functions in A-ring were synthesized and characterized according to the spectral data, by mass analysis as well as XRD analysis (compounds 6, 13 and 15). The structurally most promising compounds 6, 11–17 were investigated as antitumor agents. The in vitro antiproliferative activity was evaluated against six human cancer cell lines: estrogen receptor negative (ER−) breast adenocarcinoma (MDA-MB-231); estrogen receptor positive (ER+) breast adenocarcinoma (MCF-7); prostate cancer (PC-3); human cervical carcinoma (HeLa); lung adenocarcinoma (A549) and colon adenocarcinoma (HT-29) using MTT assay. The results of the 48h incubation time in vitro tests showed that compound 15 was the most effective against PC-3 (IC50 6.6μM), compound 17 against MCF-7 (IC50 7.9μM) cells, while compound 16 exhibited strong antiproliferative effect against both, MCF-7 (IC50 1.7μM) and PC-3 (IC50 8.7μM) cancer cells. It was also found that compounds 16 and 17 induced apoptosis in MCF-7 cells (dicyano derivative 17 stronger then dioxime 16 and reference formestane), with no distinct changes in the cell cycle of MCF-7 cells.

ChemInform Abstract: Production of Pyrans, Pyridazines, Pyrimidines, Pyrazines and Triazine Compounds Using Benzoylacetonitriles as a Precursor

AbstractReview: 85 refs.

Borrelidin B: isolation, biological activity, and implications for nitrile biosynthesis.

Borrelidin (1) is a nitrile-containing bacterially derived polyketide that is a potent inhibitor of bacterial and eukaryotic threonyl-tRNA synthetases. We now report the discovery of borrelidin B (2), a tetrahydro-borrelidin derivative containing an aminomethyl group in place of the nitrile functionality in borrelidin. The discovery of this new metabolite has implications for both the biosynthesis of the nitrile group and the bioactivity of the borrelidin compound class. Screening in the SToPS assay for tRNA synthetase inhibition revealed that the nitrile moiety is essential for activity, while profiling using our in-house image-based cytological profiling assay demonstrated that 2 retains biological activity by causing a mitotic stall, even in the absence of the nitrile motif.

Negishi Cross-Coupling Reaction as a Simple and Efficient Route to Functionalized Amino and Alkoxy Carbene Complexes of Chromium, Molybdenum, and Tungsten

Synthesis of functionalized phenyl, 2-thienyl, and N-methyl-pyrrol-2-yl Fischer carbene complexes of chromium and tungsten was achieved via a Negishi cross-coupling reaction of metalated aminocarbenes in the presence of a palladium catalyst. The reverse approach, i.e., coupling bromocarbenes with organozinc reagents, is also feasible and is particularly useful with alkoxycarbene complexes, metalation of which is not possible. Both these procedures are also suitable for the cross-coupling of molybdenum amino- and alkoxycarbene complexes. The presented methodology enables an access to the new amino and alkoxy carbene complexes bearing aldehyde, ketone, nitrile, and ester functionality.

Anticonvulsant profiles of certain new 6-aryl-9-substituted-6,9-diazaspiro-[4.5]decane-8,10-diones and 1-aryl-4-substituted-1,4-diazaspiro[5.5]undecane-3,5-diones.

Synthesis and anticonvulsant potential of certain new 6-aryl-9-substituted-6,9-diazaspiro[4.5]decane-8,10-diones (6a–l) and 1-aryl-4-substituted-1,4-diazaspiro[5.5]undecane-3,5-diones (6m–x) are reported. The intermediates 1-[(aryl)(cyanomethyl)amino]cycloalkanecarboxamides (3a–f) were prepared via adopting Strecker synthesis on the proper cycloalkanone followed by partial hydrolysis of the obtained nitrile functionality and subsequent N-cyanomethylation. Compounds 3a–f were subjected to complete nitrile hydrolysis to give the respective carboxylic acid derivatives 4a–f which were cyclized under mild conditions to give the spiro compounds 5a–f. Ultimately, compounds 5a–f were alkylated or aralkylated to give the target compounds 6a–i and 6m–u. On the other hand, compounds 6j–l and 6v–x were synthesized from the intermediates 5a–f through alkylation, dehydration and finally tetrazole ring formation. Anticonvulsant screening of the target compounds 6a–x revealed that compound 6g showed an ED50 of 0.0043 mmol/kg in the scPTZ screen, being about 14 and 214 fold more potent than the reference drugs, Phenobarbital (ED50 = 0.06 mmol/kg) and Ethosuximide (ED50 = 0.92 mmol/kg), respectively. Compound 6e exhibited an ED50 of 0.019 mmol/kg, being about 1.8 fold more potent than that of the reference drug, Diphenylhydantoin (ED50 = 0.034 mmol/kg) in the MES screen. Interestingly, all the test compounds 6a–x did not show any minimal motor impairment at the maximum administered dose in the neurotoxicity screen.

ChemInform Abstract: Concise Enantioselective Synthesis of δ,δ‐Disubstituted δ‐Valerolactones.

Abstract Efficient access to enantioenriched δ,δ-disubstituted δ-valerolactones is described. A soft Lewis acid/hard Bronsted base cooperative catalyst allowed for direct catalytic asymmetric γ-addition of allyl cyanide to ketones, producing tertiary homoallylic alcohols with a Z -configured α,β-unsaturated nitrile. Electrophilic activation of the nitrile functionality triggered 6- exo - dig cyclization, and subsequent N -acylation gave rise to the δ-valerolactone skeleton via C N bond cleavage.

Exploration of relative chemoselectivity in the hydrodechlorination of 2-chloropyridines

The chemoselectivity of hydrodechlorination in 2-chloropyridine derivatives possessing reduction-sensitive functionalities is examined. The reaction conditions employed tolerate a variety of functionalities illustrating highly chemoselective hydrodechlorination in the presence of nitrile, allyl, terminal olefin, and nitroamine functionalities in excellent yield. Chemoselective deprotection of carboxybenzyl ethers is illustrated in moderate yield.

Steric congestion at, and proximity to, a ferrous center leads to hydration of α-nitrile substituents forming coordinated carboxamides.

The question of the conversion of nitrile groups into amides (nitrile hydration) by action of water in mild and eco-compatible conditions and in the presence of iron is addressed in this article. We come back to the only known example of hydration of a nitrile function into carboxamide by a ferrous [Fe(II)] center in particularly mild conditions and very efficiently and demonstrate that these unusual conditions result from the occurrence of steric stress at the reaction site and formation of a more stable end product. Two bis(cyano-substituted) (tris 2-pyridyl methyl amine) ligands have been prepared, and the structures of the corresponding FeCl2 complexes are reported, both in the solid state and in solution. These two ligands only differ by the position of the nitrile group on the tripod in the α and β position, respectively, with respect to the pyridine nitrogen. In any case, intramolecular coordination is impossible. Upon action of water, the nitrile groups are hydrated however only if they are located in the α position. The fact that the β-substituted β-(NC)2TPAFeCl2 complex is not water sensitive suggests that the reaction proceeds in an intramolecular way at the vicinity of the metal center. In the bis α-substituted α-(NC)2TPAFeCl2 complex, both functions are converted in a very clean fashion, pointing out that this complex exhibits ligand flexibility and is not deactivated after the first hydration. At a preparative scale, this reaction allows the one-pot conversion of the bis(cyano-substituted) tripod into a bis(amido-substituted) one in particularly mild conditions with a very good yield. Additionally, the XRD structure of a ferric compound in which the two carboxamido ligands are bound to the metal in a seven-coordinate environment is reported.

ChemInform Abstract: Chemoselective Catalytic Conjugate Addition of Alcohols over Amines.

A highly chemoselective conjugate addition of alcohols in the presence of amines is described. The cooperative nature of the catalyst enabled chemoselective activation of alcohols over amines, allowing the conjugate addition to soft Lewis basic α,β-unsaturated nitriles. Divergent transformation of the nitrile functionality highlights the utility of the present catalysis.

Assessment of alteration processes on circumstellar and interstellar grains in Queen Alexandra Range 97416

Insight into the presolar and interstellar grain inventory of the CO3 chondrite Queen Alexandra Range (QUE) 97416 is gained through correlated secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM), and synchrotron-based X-ray absorption near-edge structure spectroscopy (XANES). Only one presolar silicate grain [O17/O16=(9.96±0.75)×10−4; O18/O16=(19.49±0.96)×10−4] that may have formed in a low-mass Red Giant or Asymptotic Giant Branch star occurs in the coarse-grained matrix of QUE 97416. No other presolar grains were identified. Although presolar grains are rare in QUE 97416, numerous (898±259 ppm) 15N-rich domains (δN15∼+1447‰ to +3069‰) occur in the thin section. Based on TEM of an extracted section, two 15N-rich domains are amorphous, C-bearing, and texturally uniform, and they are embedded in a ferromagnesian silicate matrix with varied grain sizes. The individual 15N-rich organic regions with high δN15 (+2942±107‰ and +2341±140‰) exhibit diverse carbon functional groups, such as aromatic, vinyl-keto, amidyl, and carboxylic functionality, while the nitrogen XANES reveals traces of nitrile functionality. QUE 97416 appears to have escaped aqueous alteration based on the absence of hydrated minerals but is thermally altered, which could have resulted in the destruction of presolar grains. However, this process at >400 °C metamorphic temperatures was inefficient in destroying the carriers of N isotope anomalies, which may indicate the resistant nature of the organic carriers and/or the limited extent of thermal metamorphism on the QUE 97416 parent body.

A green and efficient access to aryl nitriles via an electrochemical anodic oxidation

The nitrile functionality is a key building block in synthetic chemistry, and has wide applications in pharmaceuticals. However, traditional methodologies for the synthesis of nitriles are limited to harsh reaction conditions. Herein, we report a new and efficient access to aryl nitriles by an electrochemical synthesis. Compared with the conventional synthetic methods, this electrochemical synthesis is more environmentally friendly and easier to handle.

Concise enantioselective synthesis of δ,δ-disubstituted δ-valerolactones

Efficient access to enantioenriched δ,δ-disubstituted δ-valerolactones is described. A soft Lewis acid/hard Brønsted base cooperative catalyst allowed for direct catalytic asymmetric γ-addition of allyl cyanide to ketones, producing tertiary homoallylic alcohols with a Z-configured α,β-unsaturated nitrile. Electrophilic activation of the nitrile functionality triggered 6-exo-dig cyclization, and subsequent N-acylation gave rise to the δ-valerolactone skeleton via CN bond cleavage.

ChemInform Abstract: Copper‐Catalyzed Domino Synthesis of 4‐Oxopyrimido[1,2‐a]indole Derivatives.

AbstractThe reaction sequence involves sequential Cu‐catalyzed intermolecular C‐arylation of N‐(2‐halophenyl)‐3‐oxoalkanamides (I), intramolecular addition of NH to nitrile function, followed by nucleophilic attack of the formed amino group to the carbonyl moiety.

Chemoselective Catalytic Conjugate Addition of Alcohols over Amines

A highly chemoselective conjugate addition of alcohols in the presence of amines is described. The cooperative nature of the catalyst enabled chemoselective activation of alcohols over amines, allowing the conjugate addition to soft Lewis basic α,β-unsaturated nitriles. Divergent transformation of the nitrile functionality highlights the utility of the present catalysis.

Chemoselective Catalytic Conjugate Addition of Alcohols over Amines

AbstractA highly chemoselective conjugate addition of alcohols in the presence of amines is described. The cooperative nature of the catalyst enabled chemoselective activation of alcohols over amines, allowing the conjugate addition to soft Lewis basic α,β‐unsaturated nitriles. Divergent transformation of the nitrile functionality highlights the utility of the present catalysis.

Combinatorial Synthesis and in Vitro Evaluation of a Biaryl Hydroxyketone Library as Antivirulence Agents against MRSA

Antibiotic resistance coupled with decreased development of new antibiotics necessitates the search for novel antibacterial agents. Antivirulence agents offer an alternative to conventional antibiotics. In this work, we report on a family of small-molecule antivirulence agents against methicillin-resistant Staphylococcus aureus (MRSA), the most widespread bacterial pathogen. Structure-activity relationship studies led to the development of a concise synthesis of a 148-member biarylhydroxyketone library. An acylation bond-forming process afforded resorcinols (1) and aryloxy acetonitriles (2) as synthons. A Lewis-acid-activated Friedel-Crafts' acylation step involving a nitrile functionality of 2 by ZnCl2, followed by nucleophilic attack by 1 was executed to obtain biaryl hydroxyketones in excellent yields. A large number of products crystallized. This strategy affords a range of biarylhydroxyketones in a single step. This is the first collective synthetic study documenting access to this class of compounds through a single synthetic operation. In vitro efficacy of compounds in this library was evaluated by a rabbit erythrocyte hemolysis assay. The most efficacious compound, 4f-12, inhibits hemolysis by 98.1 ± 0.1% compared to control in the absence of the compound.