Cleavage of Diethyl Chromonyl α-Aminophosponate with Nitrogen and Carbon Nucleophiles: A Synthetic Approach and Biological Evaluations of a Series of Novel Azoles,Azines, and Azepines Containing α-Aminophosphonate and Phosphonate Groups

A convenient synthetic approach leading to a series of novel substituted azoles, azines, and azepines linked to the α-aminophosphonate moiety was achieved. The methodology depends on ring opening and ring closure (RORC) of the chromone ring of diethyl chromonyl α-aminophosphonate 1 via its reaction with nitrogen nucleophiles such as primary amines and 1,2-, 1,3-, and 1,4-bi-nucleophiles in ethanolic sodium ethoxide. Also, treatment of compound 1 with some acyclic and cyclic active methylene compounds under the same reaction conditions afforded interesting novel isolated and fused pyridine systems bearing phosphonate groups at the α-position. The screening of antimicrobial activity for the synthesized compounds indicates that connection of pyrazole, oxazepine, and benzodiazepine rings with α-aminophosphonate moiety exhibited good antimicrobial effects. Also, evaluation of their antioxidant properties shows that the compounds having 1,5-benzoxazepinyl and 1,5-benzodiazepinyl units in combination with α-aminophosphonic diester moiety are the most powerful antioxidant agents.     

Palladium acetate-catalysed one-pot green synthesis of bis α-aminophosphonates

Research on Chemical Intermediates - A simple and effective green method has been developed for the synthesis of a series of novel bis α-aminophosphonate derivatives (4a–j) by the...     

T3P®-promoted Kabachnik–Fields reaction: an efficient synthesis of α-aminophosphonates

A simple and efficient synthesis of α-aminophosphonates has been developed via the one-pot three-component reactions of aldehydes, amines, and trialkyl phosphites. The reactions occurred rapidly at room temperature in the presence of 1 equiv of propylphosphonic anhydride (T3P®) as the condensing agent, and the α-aminophosphonate products were obtained in high yields.     

Synthesis,X-ray Crystallographic Analysis and Bioactivities of α-Aminophosphonates Featuring Pyrazole and Fluorine Moieties

A series of novel -aminophosphonates containing pyrazole and fluorine moieties was designed and synthesized through ultrasonic-assisted condensation and solvent-free addition reactions. Their structures were verified by IR, 1H NMR, 13 C NMR and elemental analysis. The crystal structure of diethyl[(4-cyano-1H-pyrazol-3-ylamino)(3,5-difluorophenyl)methyl]phosphonate(4a, C15H17F2N4O3P) was determined by single-crystal X-ray diffraction. Compound 4a crystallizes in the triclinic system, space group P1 with a = 8.381(3), b = 10.103(5), c = 11.268(3) , = 83.772(19), = 74.726(19), = 70.964(18), V = 869.9(6) 3, Mr = 370.30, Dc = 1.414 g/cm3, Z = 2, F(000) = 384, = 0.200 mm-1, Mo Ka radiation( = 0.71073 ), the final R = 0.0487 and w R = 0.0823 for 1582 observed reflections with I 2(I). X-ray diffraction analysis reveals that there are two planes in 4a, and the dihedral angle is 71.51. Two intermolecular hydrogen bonds and a face-to-face ··· stacking interaction are observed in the crystal structure. The compounds were evaluated for their antifungal, antiviral and antitumor activities, respectively. Among them, 4b, 4c, 4g and 4h exhibit good activities on Sclerotium rolfsii Sacc at 200 μg/m L, while 4b, 4c, 4f and 4g possess good anti-TMV activities at 500 μg/m L. Unfortunately, all of the compounds showed weak antitumor activities.     

Transformations des énamines α-formylées: synthèse d’α-amino esters N,N-disubstitués

2-Dialkylaminoalkanoic esters are prepared in moderate yield by the reaction of N,N-disubstituted 2-amino-2-alkenals with dialkyl phosphonates in the presence of sodium alcoxide. A mechanism involving an α-keto-β-aminophosphonate as an intermediate is proposed.     

新型含吡唑基的α-氨基膦酸酯类衍生物的合成及生物活性

在微波无溶剂无催化条件下, 以取代吡唑甲醛、芳胺和亚磷酸二乙酯为原料合成了一系列新型含吡唑基的α-氨基膦酸酯类衍生物, 其结构经¹H NMR, ¹³C NMR, MS和³¹P NMR测试技术进行了表征. 初步生测结果表明, 部分化合物表现出不同程度的抗菌活性.     

Mécanismes de Formation d'α-Aminophosphonates

When di-n-decylphosphonate 1a or di-benzylphosphite 1b are reacted with furan imine 2a or thiophenic imine 2b , the reaction leads to an f -aminophosphonate: 3a , 3b , or 3c following an ion- or radical-based reaction.     

Ugi Reaction on α-Phosphorated Ketimines for the Synthesis of Tetrasubstituted α-Aminophosphonates and Their Applications as Antiproliferative Agents

An Ugi three-component reaction using preformed α-phosphorated N-tosyl ketimines with different isocyanides in the presence of a carboxylic acid affords tetrasubstituted α-aminophosphonates. Due to the high steric hindrance, the expected acylated amines undergo a spontaneous elimination of the acyl group. The reaction is applicable to α-aryl ketimines bearing a number of substituents and several isocyanides. In addition, the densely substituted α-aminophosphonate substrates showed in vitro cytotoxicity, inhibiting the growth of carcinoma human tumor cell line A549 (carcinomic human alveolar basal epithelial cell).     

An efficient and green preparation of 5-aminophosphonate substituted pyrimidine nucleosides under solvent-free conditions

<正>An environmentally benign and highly efficient one-pot preparation ofα-aminophosphonates under solvent-free conditions was developed.By employing this method,5-aminophosphonate substituted pyrimidine nucleosides were synthesized in good to excellent yields starting from 5-formyl-2'-deoxyuridine,aniline and dimethylphosphite.     

Self-reproduction of chirality on α-aminophosphonates: asymmetric synthesis of α-alkylated diethyl pyrrolidin-2-yl-phosphonate

A simple method for the asymmetric synthesis of α-substituted diethyl pyrrolidin-2-yl-phosphonate is described. The chiral oxazolopyrrolidine phosphonate was alkylated diastereospecifically with an alkyl halide. The key intermediate is an α-phosphonate-stabilized carbanion that can be alkylated without loss of optical activity and a single enantiomer of product was formed exclusively in 10-80% yield. The configurational assignment of the products relied on ¹H-¹H NOESY analysis of the alkylated oxazolopyrrolidine phosphonates. This represents an unprecedented case of self-regeneration of stereocenters (SRS) of cyclic aminophosphonates. The enantiomerically pure α-aminophosphonate diethyl-(2S)-(2-methylpyrrolidin-2-yl)-phosphonate, a surrogate of 2-methyl proline, was obtained upon hydrogenolysis of the chiral auxiliary in 83% yield.     

α-Aminophosphonate derivatives of triethoxysilane for the synthesis of surface-modified silica

Abstract

A convenient synthetic route for the preparation of α-aminophosphonate derivatives of triethoxysilane, attractive precursors for silica surface functionalization, was developed. The condensation of commercially available APTES with carbonyl compounds followed by Pudovik reaction of imines with diethyl phosphite yielded desired N-phosphonomethyl functionalized (3-aminopropyl)triethoxysilanes in high yields without further purification. The chemical structures of obtained products were undoubtedly proved by ¹H, ¹³C and ³¹P NMR spectroscopy, elemental analysis and mass spectrometry.     

The design and synthesis of a novel organophosphorus compound containing the structure of both β-amino acid and β-aminophosphonate

<正>A novel organophosphorus compound containing the structure of bothβ-amino acid andβ-aminophosphonate is designed and synthesized.Arbuzov reaction with P(OEt)_3,the N-Boc protected iodide 3 cannot provide the desired product but 2-oxazolidinone 4 because of the neighboring-group participation of the Boc moiety.To avoid the intramolecular participation of the carbamates,the Ts protecting group is employed and the Ts-protected iodide 5 affords the target product successfully.     

Synthesis and structure-activity relationships study of α-aminophosphonate derivatives containing a quinoline moiety

Two series of a-aminophosphonate derivatives containing a quinoline moiety have been designed and synthesized by introducing bioactive quinoline scaffold to a-aminophosphonate. The in vitro cytotoxic activities of target compounds were first investigated against two human cancer cell lines including Eca109 and Huh7 by MTT assay. Results revealed that most of target compounds exhibited moderate to high antitumor activities against the tested cancer cell lines and some demonstrated more potent inhibitory activities compared with Sunitinib. Among them, compounds 4b2 and 4b4 containing methylsubstituted aniline group were found to be more active than Sunitinib against both of two cancer cell lines, with IC50 in the range of 2.26 mmol/L–7.46 mmol/L.     

TiO2 as a new and reusable catalyst for one-pot three-component syntheses of α-aminophosphonates in solvent-free conditions

Commercially available titania (TiO₂) is reported as an extremely efficient catalyst for the synthesis of α-aminophosphonates. A three-component reaction of an amine, an aldehyde or a ketone and a dialkyl phosphite (Kabachnik–Fields reaction) took place in one-pot, under solvent-free conditions to afford the corresponding α-aminophosphonates in high yields and short times. The TiO₂ catalyzed α-aminophosphonate synthesis in the present study perhaps represents a true three-component reaction as no intermediate formation of either an imine or α-hydroxyphosphonate was observed that indicated the simultaneous involvement of the carbonyl compound, the amine and the phosphite in the transition state. Furthermore, the catalyst can be reused for several times without any significant loss of catalytic activity.     

Uncatalyzed and solvent-free one-pot three component synthesis of α-amino phosphonates

An innovative route to preaper a number of variously substituted α-aminophosphonate is presented. The protocol avoids the use of any catalyst, organic solvents, and dry reaction conditions. The synthesis of α-aminophosphonates in the present study represents a three-component reaction in which no intermediate formation of either an imine or α-hydroxy phosphonate was observed.     

Solvent-and Catalyst-free Synthesis and Antifungal Activities of α-Aminophosphonate Containing Cyclopropane Moiety

Nine new α-aminophosphonate derivatives containing cyclopropane moiety have been synthesized via conventional and microwave irradiation methods under solvent-and catalyst-free condition. The structures of the title compounds have been confirmed by 1H NMR, 31P NMR, FTIR, EI-MS and FTICR-MS. Their antifungal activities were evaluated in vivo and some of the compounds were found to exhibit excellent antifungal activities against Corynespora cassiicola, Pseudomonas syringae pv. Lachrymans, Pseudoperonospora cubensis and Sclerotinia sclerotiorum.     

Reaction of N,N-disubstituted perfluoroalkanethioamides with trialkyl phosphites. A new method for the synthesis of polyfluorinated α-aminophosphonates

The first examples of the reactions of perfluoroalkanethiocarboxylic acid amides and trialkyl phosphites are presented. The reactions are shown to be dependent on the perfluoroalkyl chain length and the presence of proton-donating reagents. New fluorinated α-aminophosphonate derivatives are obtained in moderate to good yields.     

Novel cyclic β-aminophosphonate derivatives as efficient organocatalysts for the asymmetric Michael addition reactions of ketones to nitrostyrenes

Three novel catalysts based upon cyclic β-aminophosphonate derivatives 1–3 were designed to catalyze the asymmetric Michael addition reactions of ketones to β-nitrostyrenes. Among the catalysts that have been prepared in this study, cyclic β-aminophosphonic acid monoethylester 3 showed the highest catalytic ability, giving the corresponding Michael adduct in good yields, high enantioselectivities (up to 92% ee), and high diastereoselectivities (syn:anti up to 95:5).     

The Kabachnik–Fields Reaction in the Synthesis of Polyaminophosphonate Derivatives of <Emphasis Type="Italic">p-tert</Emphasis>-Butylthiacalix[4]arene

Novel derivatives of p-tert-butylthiacalix[4]arene containing four or eight 1-aminophosphonate groups at the lower rim of the macrocycle in 1,3-alternate conformation have been synthesized via the Kabachnik–Fields reaction. These compounds are promising synthetic receptors for biologically important acids. It has been shown that complete phosphorylation of the first generation dendrimer containing eight primary amino groups is impeded in the case of cyclic ketones.     

Reusable zinc oxide nanoflowers for the synthesis of α-aminophosphonates under solvent-free ultrasonication

A simple wet chemical method is used to prepare zinc oxide nanoflowers (ZnO NFs) which were subjected to various characterization techniques such as XRD, FTIR, UV–Vis, FE-SEM, and XPS. XRD pattern indicates pure, crystalline, and monodispersed form with hexagonal wurtzite phase. The 3-D flower shape morphology with hexagonal ZnO nanorods was confirmed in FE-SEM. The synthesized ZnO NFs was used to study catalytic behavior in Kabachnik–Fields reaction under controlled ultrasound cavitation technique. High surface-to-volume ratio of ZnO NFs and the effect of ultrasonication enhances the yield of α-aminophosphonate. The catalyst was recycled and reused four times without any significant loss of its catalytic activity. Moreover, existing method becomes attractive and practical due to its easy, clean, fast, cost-effective, and eco-friendly procedure.