Synthesis Of Organophosphorus Research Articles

Organophosphorus Synthesis beyond P-Cl Bond: The Development of Shelf-stable Reagents for [RP] Transfer

: The direct chlorine-free incorporation of P1 units into organic molecules has very important synthetical value owing to environmental considerations and the prospect of accessing unique compounds with fascinating structures and useful properties. This selective survey presents a panorama of phosphorus species that are synthetic equivalents of free singlet phosphinidenes [R-P] and highlights the state-of-art of the [RP]-transfer reactions with emphasis on the synthesis of molecular architectures difficult to reach using traditional methods. Among stabilized phosphinidene precursors capable of RP-transfer are terminal transition-metal phosphinidene and phosphinidenoid complexes, dibenzo-7λ3- phosphinobornadienes, phosphinidene-phosphoranes, inversely polarized phosphaalkenes, phosphaketenes, intramolecularly base-stabilized phosphinidenes, (cyclo)polyphosphines and diphosphenes.

Palladium-Catalyzed Chemoselective Phosphorylation of Poly(pseudo)halides: A Route for Organophosphorus Synthesis.

We present an advancement in synthesizing organophosphorus compounds via chemoselective phosphorylation achieved by a palladium and SelectPhos ligand system (Pd/L1). This catalysis system exhibits remarkable chemoselectivity, even in poly(pseudo)halide substrates and overcoming toxicity and substrate scope limitations. The catalytic system is robust, which is demonstrated across diverse substrates such as chloroaryl and bromoaryl triflates. Furthermore, we present a one-pot sequential strategy combining phosphorylation with Suzuki-Miyaura coupling, providing a versatile platform for the efficient synthesis of complex organophosphorus compounds, challenging conventional reactivity paradigms.

Chemistry of Phosphorus Ylides. Part 47. Synthesis of Organophosphorus and Selenium Pyrazolone Derivatives, Their Antioxidant Activity, and Cytotoxicity against MCF7 and HepG2

Reaction of oxobutenyl- and oxophenylpropenyl-phenylpyrazolones with the active phosphacumulenes, iminovinylidene- and oxovinylidenetriphenylphosphoranes has led to pyranopyrazole and phosphoranylidenepyranopyrazole, respectively. Reaction of the pyrazolones with the stablized phosphonium ylides has resulted in pyrazolodienoates. Reaction of Woolin’s (diselenadiphosphetandiselenides) reagent with the pyrazole derivative substrates has resulted in formation of different phosphorus-selenium heterocyclic pyrazole derivatives such as oxaselenaphosphinin-, selenoxobutenyl-, selenidodiselenaphosphinyl-, and diselenidoselenadiphosphetanylvinyl pyrazoles. The possible reaction mechanism is considered, and structural elucidations are based on spectroscopic data. Antitumor and antioxidant activities of the new compounds have been evaluated. The structure-activity relationship (SAR) for the products is discussed.

The Impact of Microwaves on Organophosphorus Chemistry.

A personal account on the pioneering results on microwave (MW)-assisted organophosphorus syntheses obtained in the last decade is presented. The broad spectrum of the reactions studied exemplifies the advantages of the MW technique as a green tool regarding efficiency and the simplification of catalyst systems. Theoretical calculations for a few typical models helped us to explore the scope and limitations of the application of MW irradiation.

Application of One-Pot Three-Component Condensation Reaction for the Synthesis of New Organophosphorus–Sulfur Macrocycles

An efficient approach has been developed for the synthesis of new phosphorus–sulfur heterocycles by a one-pot three-component condensation reaction of a four-membered-ring thionation reagent [Lawesson’s reagent or its ferrocene analogue (2,4-diferrocenyl-1,3,2,4-diathiadiphosphetane 2,4-disulfide)], an alkane- or arenedithiol, and a dihaloalkane at room temperature in the presence of triethylamine. The simple synthesis method with mild conditions (room temperature and normal reactant concentrations) enhances further the application of the multicomponent reaction in the preparation of novel phosphorus–sulfur heterocycles. Six representative X-ray structures confirmed the formation of these macrocycles.

Synthesis of Secondary Phosphine Oxides by Substitution at Phosphorus by Grignard Reagents

Secondary phosphine oxides (SPOs) are important starting materials in organophosphorus syntheses, and may be the ligands in transition metal complexes. SPOs are obtained from phosphorus trichloride via double substitution by a Grignard reagent followed by hydrolysis, or from dialkyl phosphites by reaction with two equivalents of a Grignard reagent. The preparation of SPOs with two different substituents is of special importance. This minireview gives useful hints for the synthesis of a variety of SPOs that are useful intermediates. Keywords: Dialkyl phosphites, grignard reagents, P(III)-chlorides, secondary phosphine oxides, substitution, ligand.

Advantages of the Microwave Tool in Organophosphorus Syntheses

The microwave (MW) technique has become an important tool also in the organophosphorus field of organic chemistry. On the one hand, otherwise reluctant reactions, such as the esterification of P-acids, may be enhanced by the effect of MW, while on the other hand, catalysts may be omitted, or catalyst systems may be simplified on MW irradiation. This later group includes the Kabachnik–Fields reactions, alkylation of active methylene-containing compounds, O-alkylations, deoxygenations, as well as the Hirao reaction. It is also the purpose of this review to elucidate the scope and limitations of the MW tool, to interpret the MW effects, and to model the distribution of local overheatings and their beneficial effect.1 Introduction2 The Esterification of Phosphinic Acids2.1 Synthetic Results2.2 Scope and Limitation of the Application of MWs2.3 Modelling the Distribution of the Local Overheatings and Predicting­ Their Effect3 The Simplification of Catalytic Systems3.1 Replacement of the Catalyst by MW Irradiation3.1.1 The Kabachnik–Fields Reaction3.1.2 Solid–Liquid Phase Alkylation of Active Methylene-Containing Compounds3.1.3 Solid–Liquid Phase Alkylation of Phosphinic Acids3.1.4 The Deoxygenation of Phosphine Oxides3.2 The Hirao Reaction without Added P-Ligands4 Conclusions

Milestones in microwave-assisted organophosphorus chemistry

Abstract Our recent results in the field of microwave (MW)-assisted organophosphorus syntheses, especially regarding esterifications, condensations, substitutions and additions are surveyed. Beside making organic chemical reactions more efficient, it was possible to perform transformations that are reluctant on conventional heating. Another option is to substitute catalysts, or to simplify catalyst systems under MW conditions. It is also the purpose of this paper to elucidate the scope and limitations of the MW tool, to interpret the MW effects, and to model the distribution of the local overheatings and their beneficial effect. All these considerations are possible on the basis of the enthalpy of activations determined by us utilizing the Arrhenius equation and the pseudo first order kinetic equation.

Green chemical syntheses and applications within organophosphorus chemistry

Application of the microwave (MW) technique offers many advantages in organophosphorus syntheses. Reluctant reactions may take place on MW irradiation. In most cases, MWs make the reactions more efficient in respect of rate, selectivity and yield. The benefits are shown via representative examples. MW irradiation may replace a catalyst, or simplify catalytic systems. The synthesis of catalysts incorporating heterocyclic P-ligands is also discussed. Where it was relevant, structural chemical details were also provided.

Green chemistry of aldehydes and tertiary phosphines in organic and organophosphorus syntheses

GRAPHICAL ABSTRACT

ChemInform Abstract: Features of Homolytic Organophosphorus Synthesis and Its Application

AbstractReview: 25 refs.

Features of homolytic organophosphorus synthesis and its application

The features and selected applications of the homolytic organophosphorus synthesis based on the addition of phosphorous acid and its acid esters to unsaturated compounds, discovered by A.N. Pudovik in 1954.

The Potential of Microwave in Organophosphorus Syntheses

GRAPHICAL ABSTRACT

Environmentally Friendly Chemistry with Organophosphorus Syntheses in Focus

The use of the microwave (MW) technique has many advan­tages in organophosphorus chemistry. MW irradiation may replace a catalyst, or simplify a catalytic system. New reactions may also become possible under MW irradiation. In most cases, microwaves just make the reactions more efficient in respect of rate, selectivity and yield. The benefits are shown via representative examples. In another field, our methods developed for the resolution of cyclic phosphine oxides and phosphinates are summarized. After deoxygenation, the racemic or optically active P-heterocycles were used as P-ligands in platinum complexes that together with other derivatives are potential catalysts. The third topic embraces the optimization of the synthesis of dronic acids/dronates. Starting from the cor­responding carboxylic acids and using methanesulfonic acid as the solvent, 3 equivalents of phosphorus trichloride is enough as the P-reactant. Applying sulfolane as the solvent, the opti­mum set of reactants comprises 2 equivalents of phosphorus trichloride and phosphorous acid.

Cleavage of PO in the Presence of P–N: Aminophosphine Oxide Reduction with In Situ Boronation of the PIII Product

In contrast to tertiary phosphine oxides, the deoxygenation of aminophosphine oxides is effectively impossible due to the need to break the immensely strong and inert PO bond in the presence of a relatively weak and more reactive PN bond. This long-standing problem in organophosphorus synthesis is solved by use of oxalyl chloride, which chemoselectively cleaves the PO bond forming a chlorophosphonium salt, leaving the PN bond(s) intact. Subsequent reduction of the chlorophosphonium salt with sodium borohydride forms the P(III) aminophosphine borane adduct. This simple one-pot procedure was applied with good yields for a wide range of PN-containing phosphoryl compounds. The borane product can be easily deprotected to produce the free P(III) aminophosphine. Along with no observed PN bond cleavage, the use of sodium borohydride also permits the presence of ester functional groups in the substrate. The availability of this methodology opens up previously unavailable synthetic options in organophosphorus chemistry, two of which are exemplified.

Phosphinate Chemistry in the 21st Century: A Viable Alternative to the Use of Phosphorus Trichloride in Organophosphorus Synthesis.

Organophosphorus compounds are important in everyday applications ranging from agriculture to medicine and are used in flame retardants and other materials. Although organophosphorus chemistry is known as a mature and specialized area, researchers would like to develop new methods for synthesizing organophosphorus compounds to improve the safety and sustainability of these chemical processes. The vast majority of compounds that contain a phosphorus-carbon bond are manufactured using phosphorus trichloride (PCl3) as an intermediate. However, these reactions require chlorine, and researchers would like to avoid the use of PCl3 and develop safer chemistry that also decreases energy consumption and minimizes waste. Researchers have already proposed and discussed two primary strategies based on elemental phosphorus (P4 or Pred) or on phosphine (PH3) as alternatives to PCl3. However, phosphinates, an important class of phosphorus compounds defined as any compound with a phosphorus atom attached to two oxygens, R(1)R(2)P(O)(OR) (R(1)/R(2) = hydrogen/carbon), offer another option. This Account discusses the previously neglected potential of these phosphinates as replacements of PCl3 for the preparation of organophosphorus compounds. Because of their strong reductive properties, industry currently uses the simplest members of this class of compounds, hypophosphites, for one major application: electroless plating. In comparison with other proposed PCl3 surrogates, hypophosphorous derivatives can offer improved stability, lower toxicity, higher solubility, and increased atom economy. When their reducing power is harnessed to form phosphorus-carbon or phosphorus-oxygen bonds, these compounds are also rich and versatile precursors to organophosphorus compounds. This Account examines the use of transition metal-catalyzed reactions such as cross-coupling and hydrophosphinylation for phosphorus-carbon bond formation. Because the most important industrial organophosphorus compounds include compounds triply or quadruply bound to oxygen, I also discuss controlled transfer hydrogenation for phosphorus-oxygen bond formation. I hope that this Account will further promote research in this novel and exciting yet much underdeveloped area of phosphinate activation.

Synthesis of organophosphorus modified nanoparticles and their reinforcements on the fire safety and mechanical properties of polyurea

Novel organophosphorus modified nanoparticles (FRs-nanoparticles) were synthesized by the hydrolysis and condensation of both 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide modified vinyl trimethoxy silane (DOPO-VTS) and 3-triethoxysilylpropylamine. FRs-nanoparticles were incorporated into the polyurea matrix in different ratios via in situ polymerization, resulting in the formation of organic/inorganic nanocomposites. The nanocomposites were characterized by thermogravimetric analysis (TGA), real-time fourier transform infrared spectra (RTIR), microscale combustion calorimeter (MCC) and tensile testing machine. The TGA results revealed that FRs-nanoparticles could slightly catalyze the thermal degradation of the nanocomposites in nitrogen atmosphere, but significantly improve the thermal stability of the nanocomposites in air atmosphere. The T0.5 (50wt.% weight loss) of the nanocomposites was delayed by 32°C in air atmosphere. Moreover, the char yield increased from 2.3wt.% to 8.9 wt.% at 550°C when the loadings of FRs-nanoparticles was 10wt.%, indicating the catalyzing charring effect of FRs-nanoparticles. The MCC results revealed that all the nanocomposites exhibited much lower flammability compared with virgin polyurea. Furthermore, the tensile test indicated that the FRs-nanoparticles could also improve the mechanical properties of polyurea.

Ambident Reactivity of Chloro(dialkylamino)(diphenylphosphinoyl)methanes

Abstract The chemical properties of chloro(dialkylamino)(diphenylphosphinoyl)methanes have been studied using the simplest compound of this series, chloro(dimethylamino)(diphenylphosphinoyl)methane, as an example. Chloro(dimethylamino)(diphenylphosphinoyl)methane shows ambident reactivity when reacting with electrophiles and nucleophiles depending on coreactant nature, it behaves as either electrophilic substrate or phosphorus nucleophile. This fact can be explained by its dissociation in solutions with both C–Cl bond cleavage to give (dimethylamino)(diphenylphosphinoyl)methyl cation and Cl− anion and C–P bond cleavage to form chloro(dimethylamino)methyl cation and diphenylphosphinite anion. The capability of chloro(dimethylamino)(diphenylphosphinoyl)methane to produce spontaneously Ph2PO–anion allows us to recommend application in organic and organophosphorus synthesis as a synthetic equivalent (synthon) of diphenylphosphinite anion.

Reactions of amino acids with arylchlorophosphoranes and chlorophosphonium compounds

It is known that one of the general and accessible synthesis methods for organylphosphonic acids dichloride, which are the key compounds of organophosphorus synthesis [1], is the reaction of chlorophosphonium compounds I (adducts of alkenes with phosphorus pentachloride) and organylchlorophosphoranes II with various oxygen-containing compounds [2]. In the development of this method the use of the reagents with different nucleophilic centers as the transformers of chlorides I and II into organyldichlorophosphonates is promising. We have shown that amino acids can be used as such compounds. The reactions of organyltrichlorophosphonium hexachlorophosphates Ia–If and chlorophosphoranes IIa– IIg with amino acids were carried out at a molar ratio of reagents 1:(2–1). The reaction proceeds rapidly at 20–25°C for 0.1–0.2 h. The amino acid chloride hydrochlorides formed as yellow-orange solutions or precipitates. The composition of compounds was confirmed by the qualitative and quantitative analysis, and also by the data of infrared spectra, which contain the absorption bands of stretching and bending vibrations of C=O (1716–1736 cm) and N–H bonds (3150–3305, 1610–1658 cm). DOI: 10.1134/S1070363211040293

ChemInform Abstract: Ionic Liquids and Water as “Green” Solvents in Organophosphorus Synthesis

AbstractReview: 124 refs.