Phosphite Research Articles

4-carboxyanilinium phosphite: A structural, vibrational, thermal and computational study

A new organo- phosphite adduct, 4-carboxyanilinium dihydrogen phosphite (4-CAPI) was synthesized and characterized by single-crystal X-ray diffraction, FTIR and DSC. 4-CAPI crystallises in the Triclinic space group, P-1, Z = 4, with two 4-CA cations and two H2PO3− anions in an asymmetric unit. In 4-CAPI crystal the organic layer containing 4-CA cations and the inorganic layer containing phosphite anions are connected through a three-dimensional network of strong charge-assisted N–H⋯O and C–OH⋯O hydrogen bonds. The cations, 4-CA exists as a cyclic acid dimer. The infrared vibrational frequencies of 4-CAPI were assigned and the spectral features of 4-CAPI obtained suggest presence of a stronger NH⋯O and C–OH⋯O hydrogen bond interactions thus corroborating with the x-ray result. The intermolecular interaction topology of 4-CAPI has been quantitatively analyzed using the computational tool of energy framework analysis, A very high values of interaction energies are found for the hydrogen bonded anion–cation pairs. The major contribution is from electrostatic interaction.

A Novel Phosphonates Synthesized from Schiff's Base Indenoquinoxaline Derivatives and its Biological Activity

AbstractIn this study we made of reaction of 11H‐indeno[1,2‐b]quinoxalin‐11‐one with hydrazine hydrate and phenyl hydrazine to afford the corresponding hydrazineylidenes 3 a, b in good yield.A series of a novel Schiff's bases of isatin and aldehydes were synthesized by condensation of them with 11‐hydrazineylidene‐11H‐indeno[1,2‐b]quinoxaline. A number of aminophosphonates were synthesized by reaction of imines with dialkyl phosphites according to Pudovik reaction. The chemical structures of the synthesized compounds were confirmed by means spectroscopic evidences. The cytotoxic activity of ten derivatives were investigated in the liver cancer cell line HepG‐2 and the breast cancer cell line MCF‐7.Compounds 7 a, b showed higher cytotoxicity towards the liver cancer cell line HepG‐2 and compound 10 a gave higher cytotoxicity towards the breast cancer cell line (MCF7) most than the reference drug (Doxorubicin). From the above‐mentioned results it may be concluded that compounds containing bis‐aminophosphonate exhibit better activity than the aminophosphonate. The molecular docking studies of phosphonates and bisphosphonates were investigated.

Synthesis of Amidophosphates Based on 1-Ethynyl-1-Aminocyclohexane Upon Microwave Activation and their Biological Activity

The researches for developing the methods for synthesizing new functionally substituted derivatives of alicyclic dialkylamidophosphates, establishing their structure, and searching for promising biologically active compounds in their series, are modern and relevant. The given study aimed to develop the synthesis of amidophosphates based on the example of phosphorylation of 1-ethynyl-1- aminocyclohexane with dialkyl phosphites in the presence of triethylamine in carbon tetrachloride in the Atherton-Todd reaction conditions using microwave irradiation of the reaction mixture. The reaction of 1-ethynyl-1-aminocyclohexane with dialkyl phosphites was carried out in a CCl4 excess at an equimolar ratio of reagents, triethylamine was used as an HCl acceptor. The highest yields of dialkyl- N-(1-ethynylcyclohexan-1-yl)amidophosphates were achieved by adding equimolar amounts of dialkyl phosphites to the mixture of 1-ethynyl-1-aminocyclohexane, triethylamine, and CCl4 followed by the subsequent activation of the mixture in a microwave reactor (MAS-II Plus MW) (MW 102 W, 115 °C, microwave irradiation time was 3‒5 min). The composition and structure of the obtained compounds were proved by elemental analysis, IR, 1H, 13C, 31P NMR spectroscopy, and X-ray diffraction analysis (XRD). The biological tests carried out in laboratory and field conditions allowed identifying diethyl-N-(1-ethynylcyclohexan-1-yl) amidophosphate among the synthesized compounds, which produces a high growth-regulating effect on the growth, development, and yield of agricultural crops.

Copper-Catalyzed Chemo- and Enantioselective Radical 1,2-Carbophosphonylation of Styrenes.

The copper-catalyzed enantioselective radical difunctionalization of alkenes from readily available alkyl halides and organophosphorus reagents possessing a P-H bond provides an appealing approach for the synthesis of α-chiral alkyl phosphorus compounds. The major challenge arises from the easy generation of a P-centered radical from the P-H-type reagent and its facile addition to the terminal side of alkenes, leading to reverse chemoselectivity. We herein disclose a radical 1,2-carbophosphonylation of styrenes in a highly chemo- and enantioselective manner. The key to the success lies in not only the implementation of dialkyl phosphites with a strong bond dissociation energy to promote the desired chemoselectivity but also the utilization of an anionic chiral N,N,N-ligand to forge the chiral C(sp3 )-P bond. The developed Cu/N,N,N-ligand catalyst has enriched our library of single-electron transfer catalysts in the enantioselective radical transformations.

Copper‐Catalyzed Chemo‐ and Enantioselective Radical 1,2‐Carbophosphonylation of Styrenes

AbstractThe copper‐catalyzed enantioselective radical difunctionalization of alkenes from readily available alkyl halides and organophosphorus reagents possessing a P−H bond provides an appealing approach for the synthesis of α‐chiral alkyl phosphorus compounds. The major challenge arises from the easy generation of a P‐centered radical from the P−H‐type reagent and its facile addition to the terminal side of alkenes, leading to reverse chemoselectivity. We herein disclose a radical 1,2‐carbophosphonylation of styrenes in a highly chemo‐ and enantioselective manner. The key to the success lies in not only the implementation of dialkyl phosphites with a strong bond dissociation energy to promote the desired chemoselectivity but also the utilization of an anionic chiral N,N,N‐ligand to forge the chiral C(sp3)−P bond. The developed Cu/N,N,N‐ligand catalyst has enriched our library of single‐electron transfer catalysts in the enantioselective radical transformations.

Organophosphites: An Addition to the Arsenal of Organocatalysts

AbstractOrganophosphites are nucleophilic in nature and can act as a good leaving group owing to the stability of the phosphite anion. This dual reactivity makes them good candidates for nucleophilic organocatalysis. However, phosphites were introduced only in 2004 as the umpolung catalyst for acylsilane substrates utilizing sequential Brook rearrangements. Very recently, phosphites have been reported to catalyze aza‐rearrangements and radical reactions. In this review, we discuss the reactivity parameters to understand its lack of use, as well as the potential for catalysis.

Mn(OAc)3 promoted cross-coupling reaction of disulfides with dialkyl phosphites

In mild reaction conditions, a novel and facile method has been developed for the formation of C–S bonds via a Mn(iii)-promoted cross-coupling reaction of disulfides with dialkyl phosphites.

Investigating the potential of liquefaction issue of some Turkish dams during earthquakes

This research is carried out to investigate and assess the critical role of soil properties and their content in influencing the soil liquefaction phenomenon that takes place when an earthquake happens. A case study is taken into account in this work, representing the Karakaya Dam. Two research approaches were implemented to achieve the research goal, including extrapolation in Excel and numerical optimization using linear regression. The outputs revealed that the annual temperature in the future of zones around the Karakaya Dam, including Azami, Ortalama, and Asgari, would witness a moderate increase of about 3 to 6 degrees Celsius next decade. Moreover, the research confirmed that the Euphrates River discharge rate at the Karakaya Dam would witness a significant increase from (100-350 m3) to (2,590-2,640 m3) in 2029, explaining that temperature and discharge rate may influence the liquefaction. Meanwhile, the research outputs indicated that soil temperature under the Karakaya Dam and chemical elements would not variate significantly next decade. Notwithstanding, the pH number will change widely from 4.14 to 9.74 in 2029. Besides, the most significant chemical molecule concentration in the soil under the Karakaya Dam is the phosphite anion, corresponding to a minimum and maximum concentration of 1 and 2 μg/m2, respectively.

Catalyst-Free Synthesis of Phosphorothioates via P–S Coupling ­Reaction of Dialkyl Phosphites with Thiols

AbstractA catalyst-free synthesis of phosphorothioates via a P–S cross-coupling reaction of thiols with dialkyl phosphites has been studied. With presented method, various phosphorothioates were obtained by the reaction of thiols with H-dialkyl phosphites in the presence of DMSO as both solvent and oxidant under transition-metal-free conditions. Mechanistic studies showed that the reaction proceeds with formation of a known disulfide intermediate via the oxidation of thiols in the presence of DMSO. Nucleophilic substitution of dialkyl phosphite with the disulfide intermediate gave phosphorothioate. The presented method is a convenient process for the synthesis of phosphorothioates under catalyst-free conditions.

Isostructural Crystals of Bis(Guanidinium) Trioxofluoro-Phosphate/Phosphite in the Ratio 1/0, 0.716/0.284, 0.501/0.499, 0.268/0.732, 0/1—Crystal Structures, Vibrational Spectra and Second Harmonic Generation

The title structures of bis(guanidinium) trioxofluorophosphate, bis(guanidinium) trioxofluorophosphate-phosphite (0.716/0.284), bis(guanidinium) trioxofluorophosphate-phosphite (0.501/0.499), bis(guanidinium) trioxofluorophosphate-phosphite (0.268/0.732), and bis(guanidinium) phosphite are crystal-chemically isotypic. Their structures correspond to the structure of bis(guanidinium) trioxofluorophosphate which was determined by Prescott, Troyanov, Feist & Kemnitz (Z. Anorg. Allg. Chem. 2002, 628, 1749–1755). The P and O atoms of the substituted trioxofluorophosphate and phosphite anions share the same positions while the P-F and P-Hhydrido are almost parallel and oriented in the same direction. Two symmetry-independent anions and two of three symmetry-independent cations are situated on the crystallographic mirror planes. The ions are interconnected by N-H⋯O hydrogen bonds of moderate strength. The most frequent graph set motif is R22(8), which involves interactions between the primary amine groups and the trioxofluorophosphate or phosphite O atoms. Fluorine, as well as the hydrido hydrogen, avoids inclusion into the hydrogen-bond network. The Hirshfeld surface analysis was also performed for the comparison of intermolecular interactions in the title structures of bis(guanidinium trioxofluorophosphate and bis(guanidinium) phosphite. The title crystals were also characterized by vibrational spectroscopy methods (FTIR and Raman) and the second harmonic generation (SHG). The relative SHG efficiency considerably decreases from bis(guanidinium) trioxofluorophosphate to bis(guanidinium) phosphite for the fundamental 1064 nm laser line.

A nonpolar bond to hydrogen vs. lone pair: Incorporation of HPO32− and SeEO32− into a lead perrhenate framework

Two new lead perrhenate compounds, [Pb2(ReO4)2(SeO3)H2O]H2O (1) and [Pb2(ReO4)2(HPO3)H2O]H2O (2), were prepared by adding selenious or phosphorous acid to boiling concentrated solutions of lead perrhenate. Both compounds adopt the same crystal structure illustrating similar structural impact of lone pair and nonpolar hydrogen bond on one-sided coordination and formation of loose structural architectures. The crystal structure of 1 and 2, which corresponds to a novel structure type, consists of lead-perrhenate double layers interconnected by the selenite or phosphite anions into framework; the channels are filled by water molecules. We briefly discuss the chemistry of compounds containing both regular-shaped and ‘lone-pair’ or ‘inert bond’ anions.

The Hirao Reaction: Palladium-Catalyzed Cross-Coupling of Dialkyl Phosphites with Aryl Halides

Key words C(sp2)–P bond formation - palladium catalysis - phosphonates

Synthesis of ortho-Phosphated (Hetero)Arylamines through Cascade Atherton-Todd Reaction/[3,3]-Rearrangement from Arylhydroxylamines and Dialkyl Phosphites.

A practical and facile strategy for the synthesis of ortho-phosphated (hetero)arylamines from readily available arylhydroxylamines and dialkyl phosphites via cascade Atherton-Todd reaction/[3,3]-rearrangement was developed. This method is amenable to various arylhydroxylamines such as phenylhydroxylamines, naphthylhydroxylamines, and pyridylhydroxylamines, has mild reaction conditions, is oxidant-free, and has good functional-group compatibility and excellent regioselectivity.

An Efficient One-Pot Synthesis of 1-Aminophosphonates

Abstract1-Aminophosphonates are valuable compounds with wide range of applications in biological and industry. Various reaction conditions and catalysts have been reported for the synthesis of 1-aminophosphonates via three-component (dialkyl phosphite + aldehyde + amine) or two-component reaction (dialkyl phosphite + imine). Here a solvent-free synthesis of 1-aminophosphonates under very mild reaction conditions is reported. The three-component condensation reactions of dialkyl phosphite, carbonyl compound, and an amine gave 1-aminophosphonates in good to excellent yields under solvent- and catalyst-free conditions at ambient temperature. Hydrophosphorylation of imines in the presence of dialkyl phosphite under the same conditions gave also 1-aminophosphonates in good to excellent yields. These results showed that the reaction needs no catalyst or solvent for activation. It seems a tautomeric form of dialkyl phosphite (as one of the components) catalyzed the reaction. The reaction yield decreased using any solvent. In addition, a novel method is reported for the synthesis of N-deprotected 1-aminophosphonates (analogues of 1-amino acids) from N-PMP 1-aminophosphonate in the presence of TCCA. To understand the activity of the dialkyl phosphite under solvent-free conditions, the DFT calculations have provided insight into the basis of this activity.

Recovery of Metals from Electronic Waste-Printed Circuit Boards by Ionic Liquids, DESs and Organophosphorous-Based Acid Extraction.

The extraction of metals from waste printed circuit boards (WPCBs) with ionic liquids (ILs), Deep Eutectic Solvents (DESs) and organophosphorous-based acid (Cyanex 272) has been presented. The study was undertaken to assess the effectiveness of the application of the new leaching liquids, and the new method of extraction of metals from the leachate and the solid phase with or without the leaching process. Solvent extraction from the liquid leachate phase has been studied in detail with popular ILs, such as tetraoctylphosphonium bromide, {[P8,8,8,8][Br] and tributyltetradecylphosphonium chloride, [P4,4,4,14][Cl] using Aqueous Biphasic Systems (ABS) method. Trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate, [P6,6,6,14][Cyanex272], ([P6,6,6,14][BTMPP]), trihexyltetradecylphosphonium thiocyanate, [P6,6,6,14][SCN], methyltrioctylammonium chloride (Aliquat 336), as well as bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) were also used in the extraction of metals from the leachate. Two DESs (1) {choline chloride + lactic acid, 1:2} and (2) {choline chloride + malonic acid, 1:1} were used in the extraction of metals from the solid phase. The extraction behavior of metals with DESs was compared with that performed with three new bi-functional ILs: didecyldimethylammonium salicylate, [N10,10,1,1][Sal], didecyldimethylammonium bis(2-ethylhexyl) phosphate, [N10,10,1,1][D2EHPA], and didecyldimethylammonium bis(2,4,4-trimethylpentyl) phosphinate, [N10,10,1,1][Cyanex272]. The [P6,6,6,14][Cyanex272]/toluene and (Cyanex 272 + diethyl phosphite ester) mixtures exhibited a high extraction efficiency of about 50–90% for different metal ions from the leachate. High extraction efficiency of about 90–100 wt% with the ABS method using the mixture {[P8,8,8,8][Br], or [P4,4,4,14][Cl] + NaCl + H2O2 + post-leaching liquid phase} was obtained. The DES 2 revealed the efficiency of copper extraction, ECu = 15.8 wt% and silver, EAg = 20.1 wt% at pH = 5 from the solid phase after the thermal pre-treatment and acid leaching. The solid phase extraction efficiency after thermal pre-treatment only was (ECu = 9.6 wt% and EAg = 14.2 wt%). The use of new bi-functional ILs did not improve the efficiency of the extraction of metal ions from the solid phase. Process factors such as solvent concentration, extraction additives, stripping and leaching methods, temperature, pH and liquid/solid as well as organic/water ratios were under control. For all the systems, the selectivity and distribution ratios were described. The proposed extraction processes can represent alternative paths in new technologies for recovering metals from electronic secondary waste.

One-Pot Synthesis of α-Amino Bisphosphonates from Nitriles via Tf2O/HC(OR)3-Mediated Interrupted Ritter-Type Reaction.

A versatile synthesis of α-amino bisphosphonates has been achieved through one-pot interrupted Ritter-type reaction under mild conditions. The reactive Ritter intermediate nitrilium is in situ generated by treatment of nitrile with readily accessible Tf2O/HC(OR1)3, which is trapped by phosphite ester to deliver the desired product. This protocol is efficient, scalable, and well compatible with a broad scope of substrates. In addition, plentiful characteristic JP-C couplings including unusual five-bond long-range 5JP-C and 3JP-C across quaternary carbon and hetero (N) atoms were observed in 13C NMR spectra.

Formal Umpolung Addition of Phosphites to 2-Azaaryl Ketones under Chiral Brønsted Base Catalysis: Enantioselective Protonation Utilizing [1,2]-Phospha-Brook Rearrangement.

The formal enantioselective umpolung addition of dialkyl phosphites to 2-azaaryl ketones was developed under Brønsted base catalysis. The reaction involves the enantioselective protonation of the transient α-oxygenated (2-azaaryl)methyl anion generated through the 1,2-addition of the anion of dialkyl phosphite to the 2-azaaryl ketone and the subsequent [1,2]-phospha-Brook rearrangement. A chiral bis(guanidino)iminophosphorane organosuperbase efficiently catalyzed the reaction to provide enantio-enriched phosphates in high yields with good to high enantioselectivities. This is a rare example of the catalytic enantioselective protonation of transient carbanions other than enolates, constructing a trisubstituted stereogenic center α to 2-azaarenes.

Rongalite-promoted transition metal-free synthesis of S-aryl phosphorothioates

The improved procedure for the synthesis of S-aryl phosphorothioates from dialkyl phosphites (H-phosphonates), aryl iodides and elemental sulfur deals with the application of rongalite (sodium hydroxy-methanesulfinate) as the radical promoter. The reactions proceeded smoothly to give S-aryl phosphorothioates in good yields.

The Facile Strategy of Improving the Long-Term Stability of Highly Transparent Polyvinyl Chloride by Introducing Unsaturated Zn Oleate and Uracil Derivatives.

In order to improve the initial color and the long-term heat stability of super-transparent polyvinyl chloride (PVC), a series of composite heat stabilizers consisting of unsaturated Zn oleate and uracil derivatives have been designed in this paper. The uracil derivatives are 1,3-dimethyl-6-amino-uracil (DAU) and 6,6′-diamino-1,1′,3,3′-tetramethyl-5,5′-(ethylidene)bisuracil (OSU). The static thermal stability, dynamic thermal stability, and transparency were used to evaluate the properties of the stabilized transparent PVC sheets. The results indicate that the compatibility between the stabilizer and PVC was greatly enhanced by introducing an unsaturated long-chain Zn oleate and a long alkyl chain bisuracil derivative. Through the thermal discoloration test, the best ratio of DAU/zinc oleate (DAU/Zn) and OSU/zinc oleate (OSU/Zn) was determined to be 4:1, with a total amount of 3 phr in 100 phr PVC. It was verified that the combination of zinc oleate with uracil derivatives could improve the long-term thermal stability of PVC, and the DAU/Zn was better than that of the OSU/Zn. In addition, through the transmission/haze verification, adding a proper amount of epoxidized soybean oil (ESBO) and phosphite ester to the OSU/Zn system has a certain synergistic effect. The thermal stability and transparency of PVC can be remarkably enhanced.

Synthesis, Biological Activities and Molecular Docking analysis of a Novel Series of 11H-Indeno[1,2-b]quinoxalin-11-one Derivatives

In this study, olefin adducts were synthesized from Wittig reactions on carbonyl group and stereo-identity of the alkene products. The reaction of 11H-Indeno[1,2-b]quinoxalin-11-one with few stabilized phosphonium ylides yielded a combination of the corresponding E and Z olefins in each case. On the other hand, the reaction of 11H-indeno[1,2-b]quinoxalin-11-one with dialkyl phosphites gave related phosphonates. The aldol condensation reaction of 11H-Indeno[1,2-b]quinoxalin-11-one with boiling dry acetone and/or 2-butanone in presence of aluminum oxide or anhydrous potassium carbonate as a catalyst led to the formation of the β-hydroxy ketones. The nucleophilic addition reaction of acetone and/or 2- butanone to (E)-alkyl 2-(11H-indeno[1,2-b]quinoxalin-11-ylidene)acetate in presence of aluminum oxide or anhydrous potassium carbonate as a catalyst led to the formation of the corresponding an addition products.Reaction mechanisms are taken into consideration and the structural assignments of the new compounds are based on the chemical and spectroscopic evidences. The cytotoxic activity of some new compounds had been evaluated against human hepatocellular carcinoma cell line (HePG2) and human Caucasian breast adenocarcinoma (MCF7). Compounds 6b,c showed higher cytotoxicity towards breast (MCF7) most cancers cellular line than the reference drug (Doxorubicin). The binding mode of phosphonates 6 changed into similarly tested by using molecular docking studies