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Preparation of diastereomericamidosulfites or phosphonic acid amidoesters derived from a diastereomerically or enantiomerically pure phenol residue containing a chiral auxiliary is presented. The a...

The interest of organophosphorus compounds bearing chirality on the phosphorus atom has greatly expanded in last decade, due to the development of efficient stereoselective synthetic methods, using...

The NHC PH adduct IMes: PH was used to form one- and two-centered coordination compounds with tungsten and boron atoms using one or two lone pairs of phosphorus atom.

Two stereoisomers, the trans form 1a and the cis form 1b, of 2,3,7,8-tetramethyl-5,10-diphenyl-5,10-dihydrophosphanthrene dioxide (1) were formed by spontaneous oxidation in air of the corresponding 5,10-dihydrophosphanthrenes 2 and were separated by recrystallization. Both 1a and 1b were characterized by X-ray crystallographic analysis, which revealed configurations at the phosphorus and conformations of the central tricyclic system. The 31P NMR of the reaction mixture showed at first two signals at −15.3 and −15.1 ppm, which shifted to 9.11 and 10.3 ppm after purification of the reaction mixture under aerobic conditions by oxidation of phosphorus atoms. The reaction of 1b with HSiCl3 in toluene-d8 at 100 °C gave no change, whereas 1a reacted with HSiCl3 to give reduced compounds 2a and 2b under the same conditions. The trans–cis isomerization of 2 occurred via vertex inversion at phosphorus atom. VT-NMR, X-ray analysis, and density functional theory (DFT) calculation showed that the conformatio...

We synthesized new phosphorus-containing linear and macrocyclic polyphenols using organic compounds containing phosphorus-carbon bonds and the phosphorus atom of various coordination, and also with reactive acetal, aldehyde, vinylethoxy, and methylene quinone fragments as starting materials. These achievements are briefly summarized.

The reaction of dialkylphosphonites with N-(bromomethyl)phthalimide furnishes alkyl phenyl hydrogenphosphinates, dialkyl phenylphosphonates, and N-[(bromomethyl)phthalimido)]-phosphinates. The stereoselectivity of the primary product of the reaction appears to increase with the increasing size of the groups attached to the phosphorus atom.

The reaction of [Cp*Mo(H)(CO) 2 {P(NMeCH 2 ) 2 (OMe)}] with TMSOTf (Me 3 SiOSO 2 CF 3 ) afforded [Cp*Mo(CO) 2 (OTf){P(NMeCH 2 ) 2 (OMe)}] ( 2 ), showing preferential hydrido abstraction rather than OMe abstraction at the phosphorus atom. [Cp*Mo(OTf)(CO) 3 ] reacted with P(NMeCH 2 ) 2 (OMe) to afford cationic phosphite complexes [Cp*Mo(CO) 4−n {P(NMeCH 2 ) 2 (OMe)} n ][OTf] [n = 1, 2 ( 6 )] but not to give 2. Structures of 2 and 6 were determined by single crystal X-ray diffraction studies.

2,3-Oxaphosphabicyclo[2.2.2]octene 1 reacts with alcohols simultaneously according to two competitive mechanisms: bimolecular addition-elimination and unimolecular elimination-addition with the intermediacy of metaphosphonate Ph-PO 2 ( 2 ). In 1,2-dichloroethane at 60°C, cyclic phosphinate 1 reacts with methanol in the bimolecular reaction five times faster than with tert-butanol. The reaction of metaphosphonate 2 with alcohols is unselective.

Two derivatives of acetaminophen have been efficiently prepared from 4-aminophenol via a two-step procedure involving acetylation of OH and NH 2 groups and then the reaction of the acetylated compounds with diakyl acetylenedicarboxylate in the presence of triphenylphosphine. The products were obtained in good yields.

Racemic chlorophosphines react stereoselectively with chiral l-phenylethylamines or amino acid esters to give diastereomerically enriched aminophosphines 3, which were isolated as diastereomerically pure crystalline borane complexes. Oxidation, thionation, the reaction with methyl iodide provide optically active derivatives of aminophosphines. (R,S)- and (S,S)-stereomers of phosphinic acid amides were separated by crystallization and a flash-chromatography. The stereochemical properties of phosphorus acid amides were investigated. The mechanism of asymmetric induction at the trivalent phosphorus atom was rationalized.

Several novel 1-(substituted phenyl)-2-phospholene 1-oxide derivatives, which are analogs of sugars having a phosphorus atom in place of the ring oxygen of normal sugars, were synthesized from the corresponding 2-phospholenes as the starting materials. Structures of all the synthesized compounds were unequivocally confirmed by IR, 1 H, 13 C, and 31 P NMR spectral, elemental, and X-ray crystallographic analyses.

A novel convenient "one-pot" synthesis of 2-oxo-1,2 u 5 -azaphosphacyclanes 1 and 1,2 u 4 -azaphosphacyclanium salts 2 via intramolecular N-alkylation of y -halogenalkyl-substituted iminophosphoryl compounds 3 has been developed. The common nature of the reaction of intramolecular cyclization of iminophosphoryl compounds having an alkoxy group at the phosphorus atom and the Arbuzov reaction has been established.

Effect of † * P--O orbital of C-apical O-equatorial (O-cis) spirophosphorane was investigated both experimentally and theoretically. O-cis phosphoranes revealed to be much more electrophilic on the phosphorus atom than O-trans isomers by experimental studies. Theoretically, the energy of the † * P--O orbital of O-cis phosphorane was calculated to be lower than that of the † * P--C orbital of O-trans phosphorane by 18.7 kcal/mol, and the result supports the enhanced electrophilicity of O-cis spirophosphoranes compared with O-trans isomer.

A general one-pot synthesis is described for the preparation, in good overall yields, of phosphinopeptides as building blocks for peptide synthesis in the field of new enzyme inhibitors. This method, consisting of the addition of alkyl hypophosphites to imines and then in the Michael-addition of the resulting alkyl α-aminophosphonites on acrylates, affords the possibility of variations for the substituents in α and β position to the phosphorus atom and in α position to the nitrogen atom.

An investigation employing the PM3 semiempirical self-consistent field molecular orbital method to calculate structure optimization and pyramidal phosphorus atom inversion barriers for phosphines and phosphine chalcogenides 1–16 has been undertaken. The calculated structural parameters (for 1–12) and inversion barriers (for 13–16) are in good agreement with experimental results. The conformational interconversion pathways for tri-o-tolylphohphine (9), tri-o-tolylphosphine oxide (10), tri-o-tolylphosphine sulfide (11) and tri-o-tolylphosphine selenide (12) were investigated in detail. For compounds 9–12, four rotamers are possible with respect to the position of the methyl groups. In the most stable geometry of 9, two of the methyl groups are close to the phosphorus lone pair. In 10, the methyl groups assume the paddle conformation, having all methyl groups close to the oxygen atom. In 11, the most stable rotamer is similar to that in 9. In the most stable rotamer of 12, all methyl groups are far ...

A method for the determination of 31P NMR chemical shift has been developed for dialkyl and diaryl phosphonates. Increment values of functions in the vicinity of the phosphorus atom have been calculated by multi-linear regression with “Systat”.

Compounds of the type ZP(RNCH2CH2)3N where Z = a lone pair are proving to be versatile reagents and catalysts for an ever increasing number of organic transformations. These properties stem from the extraordinary basicity and low nucleophilicity of the phosphorus atom when certain Z substituents induce the bridgehead nitrogen to transannulate (even partially) to the phosphorus. When Z = O, the phosphoryl oxygen also displays unusual basicity when transannulation is caused.

Spectra of a nuclear magnetic resonance of seleno- and telluro-phosphorus compounds on nuclei 77Se, 125Te, 31P are described. The dependences of spectral parameters on a structure of the substitutes at phosphorus atom in these compounds are discussed.

MNDO calculations are performed for studying correlation between the electronic and geometrical structures and 31P NMR chemical shifts of dicoordinated phosphenium cations. A simple relationship is introduced to elucidate the 31P NMR chemical shifts of the cations from the calculated net atomic charges of the related atoms, Wiberg bond orders between the phosphorus atom and the atoms attached to it, and the bond angle at the phosphorus. The agreement of the calculated numerical results with the experimental data shows that the relationship obtained in this paper is satisfactory for the prediction of the 31P NMR chemical shifts of the dicoordinated phosphenium cations.

Single crystal X-ray diffraction studies of the macrocyclic bis(bicyclophosphoranes), [N(CH2)CMe2O)2PO2]2[(CH2)2S(CH2)2] (1) and [N-(CH2CMe2O)2PO2]2[(CH2)2 NPh(CH2)2][(CH2)2N-tBu(CH2)2] (2). revealed trigonal bipyramidal structures at the phosphorus atom. A comparison is made with the structures of related bicyclic phosphoranes containing similar ring systems that comprise both saturated (1–4) and unsaturated (5–8) members. A molecular mechanics treatment is performed which shows close agreement between the calculated and X-ray structures of 1 and 2.

The synthesis, structure and chemical features of a new class of tricyclic phosphorus-containing heterocycles are reported. Special attention is paid to the dynamics of molecules and their tendency to enter into elimination reactions. A possibility to synthesize relatively stable dibenzo-1,3,2-diazaphosphepene containing a two-coordinated phosphorus atom is considered.

New hexacoordinate phosphonium salts Ar2RZP+ X-[ar=(8-dimethylamino)-1-naphthyl] with two N→P intramolecular coordinations are described. NMR studies of these salts and the X-ray structure of one of them, 5 (R=Ph, Z=H, X=Br) show that they have a dissymmetric structure with the two Me2N groups coordinated at the phosphorus centre. Salts 4 (R=Ph or Me, Z=CH2CO2Et) react slowly with PhCHO under Wittig conditions probably because of the steric hindrance around the phosphorus atom. This is confirmed by the higher reactivity of the less hindered pentacoordinate phosphonium salts ArR2PCCH2C02Et X− 11 (R=Ph or Me) which are also much more reactive than Ph3P+CH2CO2Et Br−. This study points out the increase of reactivity of these salts due to the N→P interaction.

Reactions of γ,γ-disubstituted allenylphosphonic acid derivatives and sulfur dichloride result in formation of various types of phosphorus-containing alkenylsulfenylchlorides depending on the nature of the substituents on the phosphorus atom and the allenic system. In particular, first sulfenylchlorides containing 1,3-alkadienyl moiety were obtained.

Eversince Seyferth ran the very odd reaction which he dit not add any word, this has remained as the first example of stereochemistry of phosphorus atom centered ligand coupling reaction in the hypervalent species and the reaction is the following.(1)

Intermediate 4 is unstable and rearranges into 5. Substitution of chlorine atoms in 5 by dialkylamino groups gives 8 and 9. 8 reacts with TEA to give phosphaalkene 10, which slowly dimerizes into 11. Methylenephosphinophosphorane 9 shows unusual properties. It adds isocyanates to two phosphorus atoms to give zwitterionic structural isomers 12a,b. The structure of 12a was resolved by X-ray analysis. 9 reacts with azides unexpectedly giving the zwitterionic product 13. Reaction of 9 with hexafluoroacetone is unusual and leads to the ylid 14a,b. According to the X-ray data it exists in zwitterionic form 14b and displays a new type of coordination at phosphorus atom. HFA can react in a similar way with other phosphines. For example, with 15 it gives the double ylid 16.

Some new organometallated phosphorus compounds can be derived from the isolobal analogy. With CpFe(CO)2 = Fp = ferrio substituent as the co-ordinating complex fragment on the central phosphorus atom, the syntheses, reactivities and structures of mono-, di- and triferriophosphines, -phosphonium salts and -chalcogeno- or -alkylidenephosphoranes are reported.

The reaction of the chloro-substituted o-aminobenzoic acids 1–3 with phosphorus trichloride led to the P-chlorobenzoxaza-substituted derivatives 4–6. The reaction of the previously known 5,6-benzo-2-chloro-1,3-dimethyl-1,3,2-diazaphosphorinan-6-one 7 with trimethylsilylcyanide furnished the P-cyano derivative 8. Its structure was confirmed by a single-crystal X-ray Structure analysis. The phosphorus atom lies out of the plane of the other atoms of the heterocycle and displays a short intermolecular P–O contact. Oxidative addition of tetrachloroorthobenzoquinone (TOB) at the A5P atom of 8, 9 and 12 gave the λ4-and λ5-P-compounds 10, 11 and 13, respectively. 5,6-Benzo-2-cyano-1,3-dimethyl-1,3,2-diazaphosphorinan-6-one 8 and 4,5-benzo-2-cyano-3-methyl-1,3,2-oxazaphosphorinan-6-one 9 reacted with dichloro(cycloocta-1,5-diene)platinum(II) [(COD)PtCl2] with formation of the 1:1 complexes 15 and 16. In the reaction of 8 with hexafluoroacetone (HFA) the unusual ester derivative 17 was formed. The charact...

By coupling in pairs in all possible ways the eight hybridization types of a neutral phosphorus atom, 37 modes of formation of a phosphorus—phosphorus bond are obtained. Some experimental results illustrate these modes and structural possibilities which offer the best hope of future success are predicted. Two other possibilities were also envisaged. The one in which one phosphorus atom is neutral, the other being cationic comprises 39 different P—P+ modes of hybridization. Coupling the eight neutral hybridization types of a phosphorus atom with the 13 possible anionic ones leads to 94 modes of formation of a P—P+ bond.

Di-1-adamantylchlorophosphine 3 is obtained by a three step sequence from commercially available adamantane. Despite the bulky 1-adamantyl groups at the phosphorus atom, it reacts readily with water to give di-1-adamantylphosphine oxide 4.

In order to complex cations and neutral molecules, hosts including the phosphoramide group have been designed and studied by nmr and X-ray crystallography. Macrocyclic derivatives containing the phosphoryl group can be easily synthesized from a diamine and an appropriate diaminophosphane. The complexation of alkaline and ammonium cations has been studied. The stability of the complexes is strongly related to the preorganized character of the phosphorus ligands. The formation of bis-macrocyclic compounds, bearing an asymmetric phosphorus atom is also reported.

The low-temperature X-ray crystal structures of 1,3,2-benzodithia-phosphenium tetrachloraluminate and the corresponding neutral 2-phenyl-1,3,2-benzodithia-phosphole have been determined at 210 K. A comparison of the X-XHO charge density studies for the two systems confirms that the phosphenium cation posseses a planar ‘aromatic’ configuration. However, there are strong indications for a substantial contribution to the structure from a quinoid-like structure with about 60% of the charge localised on the phosphorus atom.

Six-membered cyclophosphaeenes, I,3-diaza-and I,3,5-triaza-2-phosphorines are characterized by a dipolar structure of ylide type with & positive charge on phosphorus atom and negative one, delokalized in an azine fragment. In n-donor substituents at a phosphorus atom as well as in electron-acceptor substituents in 4,b heterocycle position this leads to an anomalous ratio of length of formally ordinary exo-cyclic and double endocyclic bonds PNexo > PNendo. Quantum chemical analysis of the situation performed by means of SCF method in CND0/2 approximation reveals more pronounced s-character of nitrogen atoms in exocyclic bonds in comparison to endocycli ones.

The reaction of ((2,2-dimethyl-1-(trimethylsiloxy)propylidene)-trimethylsilylphosphine], 1, with pentaborane(9) under mild conditions produced the bridged phosphinopentaborane cluster ((tBu) (Me3SiO)HCP(SiMe3))B5H8, 2, in high yield. This phosphaborane reacts readily with water to quantitatively produce the corresponding P—H substituted cage compound ((tBu)(Me3SiO)HCP(H))B5H8, 3, via an electrophilic exopolyhedral substitution reaction at the phosphorus atom. All new compounds have been characterized by a variety of spectroscopic methods including 1H, 13C, 11B, 31P NMR, FT-IR and mass spectroscopic analysis.

δ5-3-dimethylamino-3-oxo-1,2,3-diazaphospholines are prepared by cyclisation of bis(dimethylami-no)phosphinallene oxides containing two electrophilic sites in position 1.3 (phosphorus atom and medium carbon allenic) with hydrazine derivatives. Mechanistic explanations of these results have been described by NMR. The IR and the 31P, 13C, 1H chemical shifts of diazaphosphollines oxides are commented.

Ligands containing phosphoryl groups form coordination compounds with different metals. The coordination compounds of such ligands with alkali metal ions are considered. The effective charge of phosphorus atom in phosphoryl group is approximately + 1, and oxygen atom effective charge is approximately -1. Phosphorus and oxygen atoms effective charges depend on the nature of the substituents at phosphorus.

The first hypervalent compounds bearing both a pentacoordinate silicon atom and a pentacoordinate phosphorus atom were synthesized by the cooperative three-component reaction of a phosphoranide a silane, and THF.

The reactions of the cyclic derivatives of the two-coordinated phosphorus atom - 2-phenyl- and 2 -acetyl-2-H-l,2,3-diazaphospholes, dialkylphosphoe sulphenyklorides, dialkyldithio- and dialkylmonothiophosphates kads to the formation of the new P(III)-fUnctiohalized diazaphosphoknes.

The olygomers consisting of regularly repeating heterocyclic fragments were synthesized by the reaction of polycondensation of the ether of p-phenylenediboric acid and tetraoxymethyloldphosphioes obtained from the different diphosphines and aldehydes. The compounds with endocyclic phosphorus atom (I) were obtained in case of using the aliphatic aldehydes, and the compounds with exocyclic phosphoruscontaining group (II) were obtained when using the hydroxyaldehydes.

Phosphorus-containing crown-ethers functionalized by heterocycle fragments have essential advantages over the usual ones. The introduction of structural units of indoles, pyrroles and indolizines to phosphorus atom of the macrocyclic chain is capable to change lipophilic, complexing, biological and other properties of the initial crown-ethers. For synthesis of such compounds we have used dihalidophosphines obtained by direct substitution of the electron-rich aromatic compounds with phosphorus (III) halides. As a result, series of highly efficient macrocyclic compounds of a nowel type have been obtained.

Reactions of carboxylic acid lactams with tervalent phosphorus chlorides, leading to N- and/or O- derivatives have been investigated. Synthetic methods for imidoylphosphites and phosphonates, mono- and bisphosphorylated azadienes have been developed. Prototropic migrations in azaallylic triad, phosphorus atom migrations in N-C-O triad and imidoylphosphite-imidoylphosphonate rearrangement were found. It was encountered, that chlorination of amidophosphites containing one to three trihalogen acetamide groups is accompanied by chlorine or N-acylamide group shift and leads to cyclic and spirocyclic phosphoranes with 1,3,2-5-oxazaphosphetanic cycle.

A general method of phosphorus heterocycle synthesis has been developed. It is based on the interaction between α,β-ethylene, acetylene P(III) derivatives and reagents, which contain electrophilic and nucleophilic centres in α,β- and α,β-positions, e.g. compounds with activated multiple bonds; β-halogenalcanols and thiols; nitrilimines, nitrilylides as 1,3-dipoles. This process is an unsynchron-ic ionic cycloaddition which begins with the attack of a phosphorus atom to the electrophilic centre of a reagent.

To investigate the features of conformational behavior for phosphorus-containing seven-membered ring we have synthesized the following compounds: The study of the three-dimensional structure was carried out by means of IR, photoelectron and dynamic NMR spectro-scopy, and electro-optical methods; the x-ray data and theoretical calculations were also taken into consideration. The three-dimensional structure of these compounds is characterized by parameters like ring conformation (chair, boat, twist or twist-boat), axial or equatorial position of exocyclic substituents on phosphorus atom, and rotational orientation of irregular substituents (OAlk or OAr). We have analyzed various spectral tests for conformational study of these species on the basis of conformational composition in different media that promoted the investigation of complex three- and four-component conformational equilibria. All results are discussed in terms of modern theoretical conceptions of stereochemistry.

The reactions of halogenides of P(III) acids with lithium derivatives of azomethines depending on the substituents at the phosphorus atom, the structure of azomethines and conditions of the reaction were studied. A method for synthesizing tile C- and N-phorphorus(III) substituted azomethines was proposed

Recently we have found1 that the condensation of racemic alkylphenylphosphinochloridite with menthol affords a mixture of diastereomers. We have also demonstrated utility of this reaction f o r the synthesis of optically active phosphines and amides1,2. In this communication we present application of neomenthanethiol and menthaneamine as chiral auxiliaries inducing optical activity at the phosphorus atom.

The paper is concerned with rhodium(1) complexes of the type acacRh(CO)L, Rh(CO)ClL2, [Rh(CO)LCl]2, [acacRh(CO)[2L and [Rh(CO)LCl]n, where L: P are monodentate, P,N- and P,P-bidentate ligands including 1,3,2-diheterophospholane and phosphorinane cycles In our studies two synthetic approaches were used, viz. the interaction of tricoordinated phosphorus derivatives with the starting rhodium substrate proceeding via the associative mechanism and the reaction of pentacoordinated phosphorus derivatives (hydrospirophosphoranes) 31P, 1H, 13C NMR, IR spectroscopy as well as X-ray and chemical studies of rhodium-coordinated 1,3,2-diheterophos-phacyclanes were carried out. The properties of these organophosphorus ligands were shown to depend on the nature and configurational rigidity of the substituents X, Y, Z at the phosphorus atom. This is illustrated by the dependence of 1J(Rh, P) and ν (CO) on the size of the phosphorus ring and the position of the heteroatoms (O, N) in the ligand molecule.

The crown ethers 1,2, containing exocyclic phosphorus groups, were obtained1 by the interaction of, bromo-, iodo-, and sulpamidoderivatives of mono- and dibenzocrown ethers with esters of trivalent phosphoric acids, alkenylphos-phonates and phosphorus pentachloride in presence of metal catalysts. On the basis of these compounds the crown ethers with various substitutes at phosphorus atom (including the polymeric ones) were synthesized. Further reaction of the crown ether 1 (X = “-” R = Ph, R′ = H) with glycol dichlo-rides gave first phosphorus-containing bis-crown ethers 3.

This report presents the studies on various methods of obtaining, structure, and chemical properties of N-acidylated amides and thiamides of four-coordinated phosphorus atom acids expressed by a general formula The yield of compounds (I) is greatly affected by the nature of X and Y atoms, so there is no universal method of synthesis for them. The optimal methods of obtaining of the compounds I have been found. The structural investigations of the compounds (I), their alkaline salts, and their alkaline salt complexes with crown-ethers has been carried out using the IR, 1H, 31P and 13C NMR, X-ray and mass-spectroscopy.

It has been recently demonstrated in our laboratory CD that ribonucleoside cyclic 3′,5′-phosphorothioates react with epoxides to give as a major product corresponding cyclic 5′,3′-phosphates, We now report the results OF our ste-reochemical studies OF this reaction. WE have Found that the diastereomerically pure (Sp) 3′.5′-CUFLPS when treated with styrene [10O]-oxide in ethanol gives the same isotopomer OF 2′,3′-[10O]cUMP as that obtained From the reaction of endo-2′.3′-cUMPS with styrene [10O]-oxide. This result strongly supports our previous assumption that reaction of 3′,5′-cNMPS with epoxides proceeds via 3′-oxathiaphosphorylated intermediate (L) which is Formed with inversion and decomposes to 2′,3′-cNMP with retention of configuration at phosphorus atom.

Starting from phosphonic, phosphorous, phosphonous and phosphoric acid chlorides new crown ethers with three- and four-coordinated phosphorus atom in the cycle were formed.

The nucleophilic substitution reactions in the series (a) P-chloro-phosphaalkenes C1-P=CR1R2; (b) P-aryloxy-λ3-imino-phosphines ArO-P=NMes; (c) P-halodiphosphenes Hlg-P=P-Mes* were studied. Reactions of the phosphaalkene -1 with N- and P-nucleophiles of type 2 represent a convenient route to obtain various phosphadienes 3.1