Synthesis of organophosphorus compounds based on the reaction of elemental phosphorus with proton-donor reagents

Russian Journal of General Chemistry - Reaction of elemental (white) phosphorus with proton-donor reagents has been studied. The following organophosphorus compounds containing P-O and P-S bonds...     

Thiocyanic Acid Derivatives in Organophosphorus Syntheses

Abstract

The application of thiocyanates and isothiocyanates as convenient and available synthones in the the syntheses of a wide variety of nitrogen- and sulfur-containing organophosphorus compounds with linear, cyclic, bipolar structures has been investigated. Thiocyanates react with organophosphorus reagents depending on the reactivity of the latter via cyano- or thiocyanate-groups substitutions, or addition to C≡N bond. The examples of reactions, including hemolytic routes, have been found and studied. Isothiocyanates can add organophosphorus reagents both to C=N and C=S bonds.     

Recent advances in the use of phosphorus-centered radicals in organic chemistry

This tutorial review aims at presenting recent contributions dealing with organic chemistry of organophosphorus radicals. The first part briefly lays out the physical organic background of such intermediates. In a second part the use of organophosphorus radicals possessing a P-H bond that can undergo homolytic cleavage as alternative mediators is detailed. The third part is focused on radical additions of phosphorus-centered radicals to unsaturated compounds, an old reaction that is being rejuvenated. Lastly, radical eliminations of phosphorus-centered radical are introduced in the fourth part. Most of the latter are relatively novel reactions, and have never been reviewed previously.     

Synthesis and Reactivity of New Organophosphorus Compounds

Abstract

Synthesis of functionally substituted organophosphorus compounds on the basis of reactions of the tri-n-butylphosphine/carbon disulfide, tri-n-butylphosphine/phenylisothiocyanate, tris(dimethylamino)phosphine/phenylisothiocyanate adducts with a wide range of different dipolarophiles are reported. The development of application of S-Li tri-n-butylphosphonio-dithioformiate derivatives to the synthesis of new types of organophosphorus compounds are reported.     

Vibrational zero point energy of organophosphorus(V) compounds

The calculation of vibrational zero-point energies (ZPEs) of organophosphorus(V) compounds is reported. The contributions of P O and PS bonds have been determined and incorporated in our empirical formula to estimate vibrational zero point energies of the investigated compounds. The calculated ZPEs for more than 80 organophosphorus compounds (V) containing these bonds correlate well with the reported available values. In addition, the comparison of these results with those obtained by quantum chemistry methods (HF/6-31G*, B3LYP/6-31G*) and by a similar empirical approach, indicates the reliability of our empirical model.     

Spectral and gamma-irradiation study of some cyclodiphosphazane compounds

The aminolysis of hexachlorocyclodiphosphazane with substituted or unsubstituted arylamines, led to the preparation of some new organophosphorus compounds. It was also possible to isolate some new geometrical isomers containing substituted arylamines. It has been found that the aminolysis reactions of 1,3-diaryl-2,2,2,4,4,4-hexachlorocyclodiphosphazane take place without ring cleavage of the cyclodiphosphazane ring system, leading to 1,3-diaryl-2-oxo-2,2,4-arylcyclodiphosphazanes. The structures of these aminophosphorus compounds were substantiated on the basis of microanalytical data, infrared, ultraviolet and proton NMR spectroscopic evidence. Hexachlorocyclodiphosphazane and some aminosubstituted cyclodiphosphazane compounds were irradiated by gamma-rays and the ultraviolet measurements before and after irradiation were discussed. It was observed that all the absorption bands show the highest absorptivity values at a particular irradiation integral dose for each of the irradiated compounds. From the ultraviolet results and mass spectrometric data, it may be suggested that the possible decomposition sites of the amino-substituted cyclodiphosphazanes are at the double bond between the four-membered ring and the exocyclic phenyl ring and at the double bond between the four-membered ring and the oxygen atom.     

Synthesis and reactivity of substituted α‐carbonylphosphonites and their derivatives

Convenient methods for the synthesis of functionalized organophosphorus compounds containing carbonyl groups as well as di‐ or trialkoxymethyl fragments attached to phosphorus, and their derivatives, starting from the available derivatives of trivalent phosphorus acids, are proposed, and some properties of the new functionalized organophosphorus compounds are presented. So, the alkylation and acylation reaction of (dialkoxymethyl) phosphonites and their analogs have been studied. It is found that the Arbuzov rearrangement of these compounds was accompanied by the phosphorus–carbon bond cleavage with unique retention of the three‐coordinate phosphorus. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:352–372, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21024     

Synthesis of Functionalized Vinylgermanes through a New Ruthenium‐Catalyzed Coupling Reaction

Vinyl‐substituted germanes react stereo‐ and regioselectively with olefins in the presence of complexes containing Ru? H and Ru? Ge bonds with the formation of functionalized vinylgermanes that cannot be synthesized by olefin cross‐metathesis procedures. The reaction opens a new catalytic route for preparation of a class of organogermanes that are potent organometallic reagents for organic synthesis because they show very low toxicity and could replace organotin compounds. The mechanism of this new catalytic route was proven to involve an interesting insertion of the vinylgermane into the Ru? H bond and β‐Ge transfer to the metal with elimination of ethylene and generation of an Ru? Ge bond, followed by insertion of the alkene into the Ru? Ge bond and β‐H transfer to the metal to eliminate the substituted vinylgermane.     

New Types of Functionally Substituted Methylphosphonites and Their Derivatives

Abstract

Organophosphorus compounds containing a functional group in the a-position of the alkyl radical are of great interest in both theoretical fundamental investigations and for practical applications. Functionally substituted methyl-phosphonites and their derivatives, belonging to this broad class of organophosphorus compounds, are convenient objects for investigating mutual effects of trivalent phosphorus and a heteroatom, or functional groups attached to it in the a-position. They have also become key substances in obtaining new organophosphorus compounds. Functionally sub-stituted compounds of tetracoordinated phosphorus have been intensively investigated in recent years; rather convenient methods of synthesis of these compounds have been proposed and their properties have been studied in detail¹. However, the corresponding compounds of tricoordinated phosphorus are not available or difficult to obtain. Recently we re-ported on the properties of halogen-substituted methylphos-phines and their derivatives². The present paper is devoted to the synthesis and investigation of the reactivity of alkoxy-, dialkylamino- and carbonyl substituted methylphos-phonites and their derivatives. In synthesis of alkoxymeth-ylphosphonites and their analogs we were the first to use labile alkoxymethylmagnesium chlorides in the reactions with tricoordinated phosphorus acid chlorides³. Previously unknown dialkoxymethylphosphonites and their analogs were obtained from hypophosphorous acid and trialkylorthofor-mates. The process of esterification and dialkoxymethylat-ion of hypophosphorous acid, being dependent on a catalyst, proceeds in different ways and results in the formation of dialkoxymethylphosphonite structures     

Synthesis of functionalized vinylgermanes through a new ruthenium-catalyzed coupling reaction

Vinyl-substituted germanes react stereo- and regioselectively with olefins in the presence of complexes containing Ru-H and Ru-Ge bonds with the formation of functionalized vinylgermanes that cannot be synthesized by olefin cross-metathesis procedures. The reaction opens a new catalytic route for preparation of a class of organogermanes that are potent organometallic reagents for organic synthesis because they show very low toxicity and could replace organotin compounds. The mechanism of this new catalytic route was proven to involve an interesting insertion of the vinylgermane into the Ru-H bond and beta-Ge transfer to the metal with elimination of ethylene and generation of an Ru-Ge bond, followed by insertion of the alkene into the Ru-Ge bond and beta-H transfer to the metal to eliminate the substituted vinylgermane.     

Catalytic hydrofunctionalization of alkynes through P-H bond addition: the unique role of orientation and properties of the phosphorus group in the insertion step

The puzzling question of alkyne insertion into Pd-P and Pd-H bonds leading to the formation of new Pd-C, C-P, and C-H bonds was explored by theoretical calculations at the CCSD(T) and B3LYP levels of theory. The key factors responsible for selectivity of catalytic hydrofunctionalization of alkynes were resolved and studied in details for the models of hydrophosphorylation, hydrophosphinylation, and hydrophospination reactions. In contrast with the generally accepted mechanistic picture, the calculations have shown that several pathways are possible depending on the nature and geometrical arrangement of the phosphorus group. It was found that the product of alkyne insertion into the metal-hydrogen bond should be easily formed under kinetic-control conditions, while the product of alkyne insertion into the metal-phosphorus bond may be formed in certain cases under thermodynamic control. For the first time, the calculations have revealed the role of the oxygen atom in the reactivity of P=P(O)R(2) groups and the role of the interactions involving the lone pair of the P=PR(2) group in the reagent. The fundamental properties of the Pd-P, C-P, and P-H bonds were reported, and the larger bond strength upon increasing the number of oxygen atoms bound to phosphorus (P=PR(2), P(O)R(2), and P(O)(OR)(2)) have been shown. The relationship between bond energy, acidity, and reactivity of the studied phosphorus compounds has been determined.     

α—氨基膦（次膦）酸类衍生物的合成及其性质

采用8种合成方法,合成了38种α-氨基膦(次膦)酸类衍生物。发现部分α-氨基膦酸化合物中含有1个结晶水。测定了化合物的pK_α值。所有化合物都具有一定除草和杀菌活性。     

Highly enantiomerically enriched chlorophosphine boranes: synthesis and applications as P-chirogenic electrophilic blocks

The stereoselective synthesis of P-chirogenic chlorophosphine boranes 4 was investigated by HCl acidolysis of the corresponding aminophosphine boranes 10. The reaction afforded the P-N bond cleavage with inversion of the configuration at the phosphorus center, leading to the chlorophosphine boranes 4 with high to excellent enantiomeric purities (80-99% ee), except in the case of the chloro-1-naphthylphenylphosphine borane 4d. Reaction conditions and workup significantly influence the enantiomeric purity of the product, with the exception of the o-anisyl- and o-tolylchlorophenylphosphine boranes, 4b and 4c, which were found to be particularly stable even after purification by chromatography on silica gel. Reaction of the chlorophosphine boranes 4 with various nucleophiles, such as carbanions, phenolates, thiophenolates, or amides, afforded the corresponding organophosphorus borane complexes via P-C, P-O, P-S, and P-N bond formation, respectively, in 34-93% yield and with up to 99% ee. This work demonstrates the importance of chlorophosphine boranes 4 as new and powerful electrophilic building blocks for the highly stereoselective synthesis of P-chirogenic organophosphorus compounds.     

Radical Addition of Bis(Trimethylsilyl)Phosphonate to Vinyltrimethylsilane: Crystal Structure of (2-Trimethylsilylethyl)Phosphonic Acid

Abstract

The formation of phosphorus-carbon bond by free radical addition of phosphorus compounds containing P-H bond to olefins has been known since more than three decades ago. Alkyl or aryl phosphins, phosphinates, phosphonates and phosphorus or hypophosphorus acid have been used in these reactions, but a little attention have been paid to silyl phosphonates. As a part of ongoing study on the structure and reactivity of organosilicon-phosphonate compounds, we synthesized bis(trimethylsi1yl) (2-trimethylsilylethyl)phosphonate (I) by the reaction of bis(trimethylsily1) phosphonate with vinyltrimethylsilane in the presence of a peroxide. The product was characterized by its ¹H and ³¹P NMR and IR spectra. Hydrolysis of (I) led to the formation of corresponding phosphonic acid (n). The crystal structure of (11) has been determined by X-ray diffraction analysis.     

Phosphoric amides. 7—Mass spectrometry of phosphoric amido esters: Fragmentation patterns and migratory aptitudes

Mass spectra of 38 organophosphorus compounds, containing both phosphate ester (P(O)OR) and phosphoramidate (P(O)NR′R″) functional groups, were recorded and discussed. Attention was focused on P? N bond cleavage, which can involve simple fission, fission accompanied by hydrogen migration from the ester group and fission accompanied by the migration of the ester R group to the departing nitrogen atom. Fragmentations characteristic for the N(β-chloroethyl) derivatives (phosphorylated nitrogen mustards) are also presented.     

Selective reduction of organic compounds with Al-acetoxy- and Al-trifluoroacetoxydiisobutylalane

The new MPV-type reagents, Al-acetoxydiisobutylalane (DIBAOAc) and Al-trifluoroacetoxydiisobutylalane (DIBAO₂CCF₃), have been prepared and their reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined in order to find out a new reducing system with unique applicability in organic synthesis. In general, the reactivity of DIBAO₂CCF₃ appears to be much stronger than that of DIBAOAc, presumably due to the acidity increase by the electron-withdrawing fluorine-substituent. Both reagents reduce aldehydes and ketones relatively slowly, but show an excellent selectivity in 1,2-reduction of α,β-unsaturated carbonyl compounds to produce the corresponding allylic alcohols in an absolutely 100% purity. In addition, the reagents achieve the regioselective cleavage of phenyl- or alkyl-substituted epoxides to the less substituted alcohols in an excellent selectivity. Moreover, both reagents show interesting features in the stereoreduction of cyclic ketones. However, these reagents show a very low or/and no reactivity toward most organic functional groups other than carbonyl and epoxy function.     

Construction of highly substituted pyrazole derivatives with P–C bond: access to racemic and enantioselective forms by conjugate addition of diarylphosphane oxides to α,β-unsaturated pyrazolones

The synthesis of organophosphorus compounds is of great importance to industrial, agricultural, and pharmaceutical chemistry. In this paper, we have reported the synthesis of highly substituted pyrazole derivatives through P–C bond formation under catalyst-free conditions. On the other hand, the first catalytic asymmetric version of this reaction has also been developed under catalysis by an isosteviol derived thiourea organocatalyst. The optically active phosphorus-containing compounds have been obtained in good chemical yields with moderate enantioselectivities.     

反式和顺式含磷稠环6,13-二硫丙基-5,12-二氧-6,13-二硫羰基-6a,7,13a,14-四氮-6,13-二磷杂二苯并(a,h)蒽烷的晶体结构

采用X射线分析测定了标题化合物的晶体结构和分子结构。化合物C_(20)H_(22)-O_2N_4P_2S4(1)为反式构型,M_r=540.63,正交晶系,空间群Pcab,a=7.255(2),b=18.297(3),c=18.576(2),V=2465.9 ~3,Z=4,D_c=1.456g/cm~(-3),最终偏离因子R=0.058,R_ω=0.049;化合物(2)为顺式构型,单斜晶系,空间群Ic,a=14.649(5),b=7.009(2),c=22.694(8),β=100.60(3)°,V=2290.1 ~3,Z=4,D_c=1.643g/cm~(-3),最终偏离因子R=0.061,R_ω=0.065。晶体结构测定结果表明,这对顺反异构体的构象明显不同:反式异构体的分子本身有对称中心且与晶体学对称中心重合,氧,氮,磷杂六员环为椅式构象,磷硫单键为轴向键,磷硫双键为平伏键;顺式异构体的分子本身无对称中心,两个氧氮磷杂六员环分别为椅式和船式构象,环上的磷硫单键为平伏键,磷硫双键为轴向键,与反式异构体恰恰相反。     

Synthesis of phosphorus ylides bearing a P-H bond from a kinetically stabilized 1,3,6-triphosphafulvene

In mixing 2,4,6-tris(2,4,6-tri-tert-butylphenyl)-1,3,6-triphosphafulvene with alkyllithium compounds and acetic acid, both of nucleophilic alkylation and electrophilic protonation occurred at the exo sp2-phosphorus atoms to afford [2,4-bis(2,4,6-tri-tert-butylphenyl)-1,3-diphosphacyclopentadienylidene](alkyl)(2,4,6-tri-tert-butylphenyl)phosphoranes which are phosphorus ylides that bear a P-H bond. A phosphorus ylide bearing both P-H and P-F bonds was obtained by reaction of 2,4,6-tris(2,4,6-tri-tert-butylphenyl)-1,3,6-triphosphafulvene with hydrogen tetrafluoroborate, and the structure was determined by X-ray crystallography. Both P=C double bond and P(+)-C(-) zwitterionic character was indicated by the metric parameters. The isolated phosphorus ylide bearing a P-H bond, [2,4-bis(2,4,6-tri-tert-butylphenyl)-1,3-diphosphacyclopentadienylidene](2,4,6-tri-tert-butylphenyl)phosphorane, showed no isomerization by H-migration to the corresponding phosphinodiphospholes, probably due to the pi-accepting ability of the unsaturated PC bonds and aromaticity of the C3P2 ring. The ylide structure and aromaticity of 2,4-diphosphacyclopenta-2,4-dienylidenephosphorane was characterized by theoretical calculations. In addition, the regioselective protonation of the lithiated phosphinodiphospholes generated from the 1,3,6-triphosphafulvene is discussed.     

Newer Aspects in Synthetic Methodology of Pyridyl Chalcogen (E═Se/Te) Compounds

Abstract

A number of synthetic protocols for the synthesis of symmetrical dipyridyl chalcogenides/dichalcogenides have successfully been developed by employing cheap, economically viable and eco-friendly reagents. The reductive cleavage of Se–Se and Te–Te bond in these versatile compounds conveniently have been achieved and a number of hitherto unknown chelating seleno/telluro ethers with varying back bones have been prepared employing appropriate alkylating agents.