Triethyl Phosphite Research Articles

New tetrathiafulvalenes containing a 2,5-bis(thiophen-2-yl)pyrrole fragment: Synthesis, optical properties, and electrochemical behavior

The reaction of 1-(3-bromopropyl)-2,5-bis(thiophen-2-yl)-1H-pyrrole with cesium 5-methylsulfanyl-2-thioxo-1,3-dithiole-4-thiolate generated in situ gave previously unknown 4-{3-[2,5-bis(thiophen-2-yl)-1H-pyrrol-1-yl]propylsulfanyl}-5-methylsulfanyl-1,3-dithiole-2-thione, and cross-coupling of the latter with 4,5-disubstituted 1,3-dithiole-2-thiones in the presence of triethyl phosphite afforded new substituted tetrathiafulvalenes containing a 2,5-bis(thiophen-2-yl)pyrrole fragment. Optical properties and electrochemical behavior of the synthesized compounds were studied, and their ability to undergo electropolymerization was confirmed.

Organocatalysis for the synthesis of optically active β-malonophosphonates

Method describes asymmetric reaction of triethyl phosphites and 2-arylidenemalononitrile catalysed by the chiral organocatalyst in solvent ethanol. The organocatalyst effectively catalyse reaction to give β-malonophosphonates in high yields (85–64%) and good to moderate enantiomeric excess (78–53%). Asymmetric reaction of triethyl phosphites and 2-arylidenemalononitrile catalysed by the chiral organocatalyst in ethanol is described. The organocatalyst effectively catalyses the reaction to give β-malanophosphonates in high yields (85-77%) and good to moderate enantiomeric excess (76-59%).

ChemInform Abstract: P‐Dodecylbenzenesulfonic Acid: A Highly Efficient Catalyst for One‐Pot Synthesis of α‐Aminophosphonates in Aqueous Media.

A highly efficient one-pot three-component reaction of aldehydes or ketones, amines, and trimethyl or triethyl phosphite catalyzed by p-dodecylbenzensulfonic acid is developed for the synthesis of α-aminophosphonates at room temperature in water. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:174–178, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21079

A straightforward synthesis of indazolo[3,2-a]isoquinolin-6-amines

Abstract 4-Substituted 1-bromoisoquinolin-3-amines were subjected to Suzuki coupling with o -nitrophenylboronic acid to yield 1-(2-nitrophenyl) isoquinolinamines, which participated in Cadogan cyclization with triethyl phosphite under microwave irradiation in a sealed vial to yield fluorescent indazolo[3,2- a ]isoquinolin-6-amines. The new compounds were also functionalized by transformation of the amino group.

Electrocatalytic Fast and Efficient Multicomponent Approach to Medicinally Relevant (2‐Amino‐4H‐chromen‐4‐yl) phosphonate Scaffold

ABSTRACT‘One‐pot’ electrocatalytic transformation of salicylaldehydes, malononitrile, and triethyl phosphite in an undivided cell results in the formation of diethyl (2‐amino‐3‐cyano‐4H‐chromen‐4‐yl)phosphonates in 88–93% substance yields and 880–930% current efficiency via complex multicomponent process. This novel electrocatalytic chain process opens an effective, fast, and convenient way to cyano‐functionalized (2‐amino‐4H‐chromen‐4‐yl)phosphonate systems which are promising compounds for biomedical applications. This efficient electrocatalytic approach to the (2‐amino‐4H‐chromen‐4‐yl)phosphonate scaffold represents novel synthetic concept for multicomponent reactions (MCR) strategy and allows to combine the synthetic virtues of conventional MCR with ecological benefits and convenience of facile electrocatalytic procedure.

Phosphorus derivatives as electrolyte additives for lithium-ion battery: The removal of O2 generated from lithium-rich layered oxide cathode

Direct internal pressure measurements of the cylindrical Li-ion cells with a mixture of LiCoO2 and Li1.167Ni0.233Co0.1Mn0.467Mo0.033O2 (a solid solution between 0.4 Li2Mn0.8Ni0.1Mo0.1O3 and 0.6 LiNi0.4Co0.2Mn0.4O2) as cathode and graphite as anode have been performed during cell charging. Cell internal pressure at the end of charging is greatly reduced from 2.85 to 0.84–1.84 bar by adding a small amount of phosphorus derivatives such as triphenyl phosphine (TPP), ethyl diphenylphosphinite (EDP), and triethyl phosphite (TEP) into a carbonate-based electrolyte. The phosphorus derivatives are supposed to react with O2 generated from the decomposition of the Li2MnO3 component. The chemical states of additive molecules before and after the charging process have been characterized with a nuclear magnetic resonance (NMR) spectroscopy and gas chromatography–mass spectrometry (GC–MS). It has also been shown that those additives improve the cycle life when applied in coin full cells.

Synthesis of new (3-fluoroimidazo[1,2-a]pyridin-2-yl)-phosphonates

New (3-fluoroimidazo[1,2-a]pyridin-2-yl)phosphonates were synthesized by a tandem reaction of imidoyl chlorides with two equivalents of triethyl phosphite.

Synthesis of Functionalized Phosphonates and Chromenes via Catalyst-Free Multicomponent Reactions in Water

Stable derivatives of phosphonates were prepared using multicomponent reactions of dialkyl acetylenedicarboxylate with 4-hydroxycumarin in the presence of trimethyl or triphenyl phosphite in good yields. Chromene derivatives were produced by using triethyl phosphite and dialkyl acetylenedicarboxylate in the presence of 4-hydroxycumarin in excellent yields.

ChemInform Abstract: Synthesis and Crystal Structure Study of Diethyl Aryl(benzo[d]thiazol‐2‐ylamino)methyl Phosphonates.

AbstractThe title compounds (IV) are conveniently obtained by a three‐component reaction between 2‐aminobenzothiazole (I), various aromatic aldehydes (II), and triethyl phosphite (III) under solvent‐free and green reaction conditions.

SYNTHESIS OF NEW (3-FLUOROIMIDAZO[1,2- a ]PYRIDIN-2-YL)-PHOSPHONATES

New (3-fluoroimidazo[1,2-a]pyridin-2-yl)phosphonates were synthesized by a tandem reaction of imidoyl chlorides with two equivalents of triethyl phosphite. Authors: A. Yu. Aksinenko, T. V. Goreva, T. A. Epishina, and V. B. Sokolov English Translation in Chemistry of Heterocyclic Compounds, 2013, 49 (3), pp 417-420 http://link.springer.com/article/10.1007/s10593-013-1262-9

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol–gel method: Bonding to titanium and scanning electron microscopy

ObjectivesHydroxyapatite (HA), fluor-hydroxyapatite (FHA) with varying levels of fluoride ion substitution and fluorapatite (FA) production has been characterised and optimised by the sol–gel method and the dissolution and biological properties of these materials were investigated. It was the objective of this study to investigate the potential bond strength and interaction of these materials with titanium. MethodsHA, FHA and FA were synthesised by a sol–gel method. Calcium nitrate and triethyl phosphite were used as precursors under an ethanol–water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the FHA and FA sol–gels. Using a spin coating technique the sol–gels were coated onto commercially pure titanium disks and crystallised at various temperatures. Using scanning electron microscopy (SEM) and elemental analysis, the surface characteristics, coating thickness and interaction of the Ti substrate and coating were investigated. The bond strengths of the coating to the Ti were investigated using an Instron Universal Load Testing Machine. Statistical analysis was performed with a two-way analysis of variance and post hoc testing with a Bonferroni correction. Results(1) Coating speed inversely influenced the coating thickness. (2) Increasing fluoride ion substitution and heating temperature significantly increased bond strength and (3) increasing fluoride ion substitution increased the coating thickness. SignificanceFHA and FA synthesised using the sol–gel technique may offer a superior alternative to coating titanium implants with HA and plasma spraying. HA, FHA and FA materials synthesised by the sol–gel method may also have a use as bone grafting materials.

P‐Dodecylbenzenesulfonic Acid: A Highly Efficient Catalyst for One‐Pot Synthesis of α‐Aminophosphonates in Aqueous Media

ABSTRACTA highly efficient one‐pot three‐component reaction of aldehydes or ketones, amines, and trimethyl or triethyl phosphite catalyzed by p‐dodecylbenzensulfonic acid is developed for the synthesis of α‐aminophosphonates at room temperature in water. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:174–178, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21079

Chemoselective deoxygenation of 4,5-dinitroacenaphthenequinone with hexaethyltriamidophosphite

Deoxygenation under the action of the P(III) derivatives is widely used in organic chemistry [1, 2]. Among the variety of reactions a separate group includes the deoxygenation of nitro compounds with the P(III) derivatives resulting in the nitrogencontaining heterocycles of different structures [3]. The tertiary phosphines and phosphites are most commonly used as the P(III) derivatives. One of the most studied reactions of this type is the cyclization of nitroarenes to form the corresponding nitrogen-containing heterocycles (indoles, pyrrolopyrimidines, carbazoles, quinolines) under the action of the phosphorous acid esters. Presumably, the reaction proceeds through the intermediate formation of nitrenes. If 2-nitrobiaryls were used, the nitrene inserts on the C–H bond adjacent to the aryl moiety, to give the corresponding carbazoles [4, 5] or δ-carbolines [6]. The reaction of 2nitrophenylsulfide with an excess of triethyl phosphite, resulting in phenothiazine, can be attributed to the same type of the reactions [7, 8]. If the aryl contains a double bond ortho-positioned relative to the nitro group (o-nitrostyrene), the nitrene inserts on the β-C– H bond of the vinyl moiety to give the substituted indoles [9–11]. The reactions of o-dinitrobenzene with the P(III) derivatives should be specially noted. For example, under the action of triethyl phosphite, diphenylethylphosphinite, or methyldiethylphosphonite one of the nitro groups is substituted by the phosphorus moiety and ethyl nitrite is eliminated [12]. At the same time, the reduction of 2,2'-dinitrobiphenyl with the gaseous PH3 stops when benzocinnoline-2,2'dioxide forms [13].

3-(Dialkoxyphosphoryl)-N-confused Phlorin and Porphyrin. Synthesis, Stereochemistry, and Coordination Properties

A 3-phosphonated N-confused phlorin 3 was synthesized by the reaction of N-confused porphyrin 1 and trimethyl or triethyl phosphite 2 in the presence of acetic acid in good yield. The presence of hydrogen and aryl substituents in one of the meso positions (C5) generates a stereogenic center, resulting in configurationally stable enantiomers. The enantiomers were separated by HPLC and characterized by the circular dichroism method for the first time in the case of phlorin. Further oxidation of 3 by DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) afforded the achiral 3-phosphonated N-confused porphyrin 4. Chiral chlorozinc 4-Zn and chlorocadmium 4-Cd, as well as achiral nickel(II) complexes 4-Ni were also characterized. For 4-Cd in the solid state, formation of a dimer consisting of heterochiral subunits joined by two H-bonds was established by a single crystal X-ray analysis. For 4-Cd, separation of enantiomers was achieved. Slow racemization of 4-Cd in solution prevented the absolute configuration determination by the X-ray method indicating the labile character of the complex. The relationship between circular dichroism and absolute configuration of 3a and 4-Cd was established on the basis of TD-DFT calculations.

ChemInform Abstract: Cerium(IV) Oxide as a Neutral Catalyst for Aldehyde‐Induced Decarboxylative Coupling of L‐Proline with Triethyl Phosphite and Nitromethane.

AbstractCeO2 is found to be highly efficient for the three‐component reactions to yield 1,2‐disubstituted pyrrolidines.

ChemInform Abstract: Pentanidium‐Catalyzed Enantioselective α‐Hydroxylation of Oxindoles Using Molecular Oxygen.

AbstractHydroperoxide oxindoles are formed as by‐products.

New azaheterocyclic aromatic diphosphonates for hybrid materials for fuel cell applications

New azaheterocyclic aromatic diphosphonate derivatives of benzimidazole and benzotriazole were synthesized by nickel-catalyzed Arbuzov reaction of 4,7-dibromo-2,1,3-benzothiadiazole with triethyl phosphite, followed by reductive sulfur extrusion reaction and cyclization. This new strategy allowed us to obtain these compounds with high efficiency, with the generation of these azaheterocyclic aromatic diphosphonate derivatives in good to excellent yields, since these compounds could not be synthesized by direct cross-coupling reactions catalyzed by palladium or nickel. All compounds were characterized by NMR, IR spectroscopy and mass spectrometry (low and high resolution). NMR studies of compound 9 showed the presence of only one tautomeric form, on the NMR time scale, in different solvents and at different concentrations.

Synthesis and Crystal Structure Study of Diethyl Aryl(benzo[d]thiazol‐2‐ylamino)methyl Phosphonates

ABSTRACTA three‐component synthesis of α‐aminophosphonate is described from a reaction between aldehydes, 2‐aminobenzothiazole, and triethyl phosphite in the presence of InCl3 as a catalyst under solvent‐free conditions for the generation of the particular α‐aminophosphonates. These products have two potentially biologically active parts, aminophosphonate and benzothiazole. This method offers advantages such as short reaction times, good yields, solvent‐free conditions, and easy workup with the green aspects by avoiding toxic catalysts and solvents. The crystal structure of 4b has been determined by X‐ray crystallography. This compound crystallizes in the monoclinic space group C2/c with cell parameters a = 21.9285(5) Å, b = 10.3221(2) Å, c = 18.5979(5) Å, β = 108.759(3)°, V = 3985.99(18) Å3, Dcalc = 1.301 mg m−3, and Z = 8. The final R value is 0.0501 for 3741 reflections. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 24:58–65, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21063

Trivalent organophosphorus reagent induced pinacol rearrangement of 4H-cyclopenta[2,1-b:3,4-b′]dithiophen-4-one

In this Letter we report on the reaction of 4H-cyclopenta[2,1-b:3,4-b′]dithiophen-4-one with various trivalent organophosphorus derivatives, with an emphasis on the final products depending on the applied reagents. No reaction occurred upon treatment with either triphenyl- or tricyclohexylphosphine, whereas addition of triethyl phosphite or tri(n-butyl)phosphine resulted in pinacol rearrangement. Structure elucidation of the isolated 5H-spiro(benzo[1,2-b:6,5-b′]dithiophene-4,4′-cyclopenta[2,1-b:3,4-b′]dithiophen)-5-one was achieved by combined NMR experiments, theoretical chemical shift and geometry calculations, and single crystal X-ray analysis.

Expeditious Microwave-Assisted Synthesis of Functionalized Oxaphosphaphenanthrenes and Chromenes via Multicomponent Reactions of Trivalent Phosphorus Nucleophiles

Stable derivatives of oxaphosphaphenanthrenes were prepared by using the reactions of dialkyl acetylenedicarboxylate with 3-bromo-2-naphthol in the presence of trimethyl or triphenyl phosphite under microwave conditions at 70°C in good yields. Under similar conditions, chromene derivatives were produced by using triethyl phosphite and dialkyl acetylenedicarboxylate in the presence of OH-acids in excellent yields.