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[16]Norcorrole is an antiaromatic ring-contracted porphyrinoid. Here, we show that the phosphorus insertion of the free-base [16]norcorrole switches its antiaromaticity to aromaticity. The treatment of a free-base meso-dimesityl[16]norcorrole with phosphorus tribromide in pyridine afforded an [18]norcorrole P(V) complex, which exhibited porphyrin-like absorption and fluorescence spectra. The phosphorus center adopted a distorted tetragonal pyramidal coordination geometry. The distinct aromatic nature of the [18]norcorrole P(V) complex was corroborated both experimentally and theoretically.

Dichlorophosphoranides featuring N,N-dimethyl-N′-arylformamidine substituents were isolated as individual compounds. Dichlorophosphoranide 9 was prepared by the multicomponent reaction of C-trimethylsilyl-N,N-dimethyl-N′-phenylformamidine and N,N-dimethyl-N′-phenylformamidine with phosphorus trichloride. Its molecular structure derived from a single-crystal X-ray diffraction was compared to the analogous dibromophosphoranide prepared previously by us by the reaction of phosphorus tribromide with N,N-dimethyl-N′-phenylformamidine. It was shown that a chlorophosphine featuring two N,N-dimethyl-N′-mesitylformamidine substituents reacted with hydrogen chloride to form dichlorophosphoranide 11. Its molecular structure was also determined by X-ray analysis and compared with that of closely related dichlorophosphoranide C.

This study describes simple synthetic method to prepare 1-(2-methoxybenzyl)-1,10-phenanthrolin-1-ium bromide from gandapura oil. The salt were synthesized in four steps. Initially, commercial gandapura oil was directly subjected to the alkylation reaction under basic condition using dimethyl sulfate to give methyl 2-methxybenzoate in 86% yield. Next, the produced benzoate ester was reduced by LiAlH4 to produce 2-methoxybenzyl alcohol in 67% yield. The treatment of benzyl alcohol with phosphorus tribromide under solvent free condition produced the corresponding benzyl bromide (in 67% yield), which was directly introduced into bimolecular nucleophilic substitution reaction with 1,10-phenantroline monohydrate to finally give the desired product in 63% yield.

The chemical reactivity of 3-(dimethylamino)-1-(2-hydroxyphenyl)prop-2-en-1-one (1) towards some phosphorus reagents was studied. The enaminone 1 was cyclized into diethyl 2-phosphonochromone 2 via its treatment with diethyl phosphite in basic medium. However, its reaction with triethoxy phosphonoacetate gave the substituted pyrone phosphonate 3. In addition, two novel examples of 4-(dimethylamino)-6-(2-hydroxyphenyl)-2-sulfido-4H-1,3,2-oxathia-phosphinines 6 and 7 were obtained from treatment of enaminone 1 with O,O-diethyl dithiophosphoric acid and Lawesson’s reagent. When enaminone 1 was also treated with phosphorus decasulfide, it was turned into 4H-thiochromene-4-thione while its treatment with phosphorus tribromide, phosphorus oxychloride, or phenylphosphonic dichloride, 4H-4-oxo-chromene was isolated in all cases. The possible reaction mechanisms of the formation of these products were discussed. The structures of newly isolated products were established by elemental analysis and spectral t...

ansa metallocene complexes of Ti, Zr and Hf were synthesized, characterized and tested as catalysts for homogeneous ethylene polymerization. The ligand system comprises two indenyl moieties tethered at the 1,1′-positions via a 2,2′-dimethyl biphenylene bridge. The ligand precursor was obtained by the reduction of diphenic acid using lithium aluminum hydride (LiAlH4), followed by the reaction with phosphorus tribromide, and, finally, the reaction with indenyllithium. The corresponding group (IV) metal complexes were synthesized by deprotonation of the ligand precursors using n-BuLi followed by reactions of the corresponding metal tetrachloride. After activation with methylaluminoxane (MAO), the zirconium and hafnium complexes proved as highly active catalysts for ethylene polymerization. The zirconium complex 6 showed the best performance with 12,460 kg PE/mol cat. h. The titanium complex 5 showed no catalytic activity obviously because of decomposition reactions.

Novel chromonyl phosphonic acid 3, diethyl chromonyl phosphonate 4, and diethyl chromonyl pyridinyl phosphonate 5 were obtained from treatment of 2-cyano-3-(4-oxo-4H-chromen-3-yl) prop-2-enamide (2) with phosphorous acid and its diesters. Also, an efficient route to functionalized phosphorus heterocycles such as 1,2,3-diazaphosphinane, 1,2,3-thiazaphosphinine and 1,2-azaphosphole bearing a chromone ring was achieved via reaction of compound 2 with some phosphorus sulfides and phosphorus tribromide. A key part of the reaction mechanisms is discussed. Structures of the new synthesized products were established on the basis of spectral data (IR, ESI-MS, 1H-, 13C and 31P-NMR spectra). An efficient route to functionalized phosphorus heterocycles such as 1,2,3-diazaphosphinane, 1,2,3-thiazaphosphinine and 1,2-azaphosphole bearing a chromone ring was achieved via reaction of 2-cyano-3-(4-oxo-4H-chromen-3-yl)prop-2-enamide with some phosphorus sulfides and phosphorus tribromide.

The purpose of this paper is to study the molecular dynamics simulation of phosphorus tribromide (PBr3) as the condensed inorganic liquid. To this aim, four regional intermolecular potential functions of phosphorus tribromide in the gas phase were considered. The potential energy data of 9 phosphorous tribromide configuration dimers were calculated at the B3LYP/6-31 + G (d) level of theory. The calculated potential data were employed to construct a 4-site all-atom force field model. Then, the force field parameters were used to perform the molecular dynamics simulations and compared the simulation results with experimental data. Quantitative agreements for the atomic number density, internal energy, enthalpy, heat capacity and radial distribution function over a wide range of experimental conditions were obtained as a consequence of the parameters force field validation without using experimental data a priori.

In certain countries, many of the reagents used to transform carboxylic acids to acyl halides such as phosphorus trichloride, phosphorus tribromide, phosphorus pentachloride, phosphoryl chloride, thionyl chloride and sulfuryl chloride are difficult to come by. Against this background, the authors developed the reaction system triphenylphosphine (PPh3) – bromotrichloromethane (BrCCl3) to prepare acyl halides in situ. In the following, the use of this reagent combination is joined with the reaction of the in situ prepared acyl halides with nitrogen nucleophiles, specifically with hydrazines, methylamine and anilines. The reaction is also used in an intramolecular variant by the reaction of maleanilic acids to N-arylmaleimides.

Cyclic zwitterionic phosphoranides 2a,b were found to be intermediate products in the reaction of N,N-dimethyl-N′-(aryl)formamidines with PBr3. The structure of phosphoranide 2a was determined by means of the X-ray and quantum chemistry investigations. Mechanism of its formation was proposed based on Density functional theory (DFT) calculations. Reactions of 2 with amines and selenium yielded either C-phosphorylated formamidines or benzazaphospholes. The first example of intramolecular heterocyclization of a pentavalent phosphorus derivative 15b into 3Н-1,3-benzazaphosphole has been demonstrated.

α-Azido alcohols are generated by treating aldehydes with hydrazoic acid in chloroform. These adducts are transformed into geminal azido–halo compounds through the reaction with phosphorus trichloride or phosphorus tribromide, whereas α-azidoalkyl esters are isolated after interaction with acyl chlorides.

A series of novel 1,3,4,2-oxadiazaphosphepino[6,7-c]quinolinones 3–5, 9, and 11 have been synthesized from treatment of 4-hydroxy-1-methyl-3-[1-(2-phenylhydrazinylidene)ethyl]quinolin-2(1H)-one (2) with some phosphorus sulfides, diethyl phosphite and phenyl phosphonic dichloride, respectively, in dry dioxane. Also, reaction of hydrazone 2 with tris(2-chloroethyl)phosphite under the same reaction conditions gave pyrazolo[3,4:4′,3′]quinolino[5,1-c][1,4,2]oxazaphosphinine 10. However, when hydrazone 2 was treated with phosphonic acid, phosphorus tribromide or phosphorus oxychloride, 3,5-dimethyl-1-phenyl-1,5-dihydro-4H-pyrazolo[4,3-c]quinolin-4-one (7) was isolated in all cases. The compounds were evaluated for their antioxidant activities. Among the synthesized compounds, 1,3,4,2-oxadiazaphosphepino[6,7-c]quinolinone-2-sulfide 5 and its analogue 2-oxide 11 exhibited higher antioxidant activities than the standard antioxidant.

A scalable and cycle process for 2,4-dibromopyrimidine is developed by bromination of 2,4-dichloropyrimidine using phosphorus tribromide. Compared with the literature reported before, the amount of bromination agent-phosphorus tribromide has been greatly reduced and purification of the product by recrystallization is realized. The total yield of 2,4-dibromopyrimidine can reach to 85.4%. The process is more suitable for scale-up production.

A range of inorganic and organoelement halides was evaluated as acidic promoters of direct Nin-formylation of tryptophan. In addition to Me3SiBr, the less expensive PBr3 was found to be highly efficient and was selected for further optimization. A convenient and reproducible synthetic procedure for Nin-formyltryptophan hydrobromide developed in this way was scaled to 150 mmol and successfully extended to some derivatives of Trp and closely related indoles as detailed in the present paper. The scope of the method seems to be restricted to indoles substituted at C-3. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

A new synthesis of 7-dehydrocholesterol (provitamin D3) from cholesterol is described, which gives a higher yield than the well known Windaus synthesis. The synthesis is carried out via a 7-bromocholesteryl ester, from which hydrogen bromide is eliminated to give an ester of 7-dehydrocholesterol. Careful hydrolysis of the impure 7-bromocholesteryl benzoate affords either 7-α- or 7-β-hydroxycholesteryl-3 benzoate depending on the reagent. The two epimeric 7-bromocholesteryl benzoates are prepared from the hydroxy-compounds by interaction with phosphorus tribromide; the two hydroxy-compounds are regenerated by hydrolysis.

The behaviour of poly(methyl methacrylate) was examined in the presence of phosphorus tri-bromide (PBr3) with varying concentrations. Films were cast from common solvent and subjected to TG, DTA, DTG, IR and Py-GC-MS for evaluating the degradation routes. Despite early decomposition of the blends, certain tempera-ture zones were identified for stabilization of the system. New products were found and mecha-nisms of their formation were proposed. Pyro-lysis of the blends was also carried out at dif-ferent temperatures to ascertain the nature of interaction between the constituents of the system.

3-(4-chlorophenoxy)-2,4-diisopropyl-2,3,4,5-tetrahydro-1H-benzo[e][1,3,2]diaza-phosphepine was synthesized starting from 1,2-bis(bromomethyl)benzene by reacting with 2 equimolar isopropyl amine, one equimolar PBr3 and then one equimolar 4-chlorophenol, respectively. The Staudinger reaction of the diazaphphosphine with a series of alkyl azides gave the corresponding iminophosphoranes. Antibacterial activities of the synthesized iminophosphoranes were screened

A facile and efficient synthesis Of Substituted pyridin-2(1H)-ones has been developed by the reaction of readily available 1-carbamoyl-]-[3-(dimethylamino)propenoyl]cyclopropanes with phosphoryl chloride or phosphorus tribromide in dichloromethane at room temperature.

Phosphorylation of N-trimethylsilyl- and N-dimethyl-tert-butylsilylpyrroles with phosphorus tribromide in pyridine proceeds selectively at position 3 of the pyrrole ring. Removal of the trialkylsilyl protecting group has furnished the first representatives of N-unsubstituted 3-phosphorylated pyrroles. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:93–96, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20416

6‐Substituted‐dibenzo[d, f][1,3,2]dioxaposphepin‐6‐oxides, sulfides, and selenides (5a–i, 6a–d, and 7a–d) were synthesized by reacting 2,2′‐biphenol (1) with phosphorus tribromide in the presence of triethylamine at 0–30°C and subsequent reaction of the monobromide (2) with different Grignard reagents (3) at room temperature. The products (4) were converted to corresponding oxides, sulfides, and selenides (5a–i, 6a–d, and 7a–d) by oxidation with H2O2 at room temperature and refluxing with sulfur and selenium respectively. The chemical structures of all the products were confirmed by analytical, IR, NMR (1H, 13C, and 31P), and mass spectral data. Most of these compounds exhibited moderate antimicrobial activity.

Chlorination of α-hydroxyphosphonate anthracen-9-yl(5,5-dimethyl-2-oxo-2λ 5 -1,3,2-dioxaphosphinan-2-yl)methanol ( 11) using thionyl chloride unexpectedly yields 10-(5,5-dimethyl-2-oxo-2λ 5 -1,3,2-dioxaphosphinan-2-ylmethylene)anthracen-9(10 H)-one ( 13), 2-(10-chloroanthracen-9-ylmethyl)-5,5-dimethyl-2λ 5 -1,3,2-dioxaphosphinan-2-one ( 14), and 10-(5,5-dimethyl-2-oxo-2λ 5 -1,3,2-dioxaphosphinan-2-ylmethylene)-9,10-dihydroanthracen-9-ol ( 15) in addition to 2-[anthracen-9-yl(chloro)methyl]-5,5-dimethyl-2λ 5 -1,3,2-dioxaphosphinan-2-one ( 12). The reaction of 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphinane ( 5) with 9-anthraldehyde leads to 2-chloro-1,1-dimethylethyl hydrogen 10-(5,5-dimethyl-2-oxo-2λ 5 -1,3,2-dioxaphosphinan-2-ylmethylene)-4a,9,9a,10-tetrahydroanthracen-9-ylphosphonate ( 20) in addition to 12. Bromination of 11 with phosphorus tribromide affords the 10-bromoanthracen-9-yl product, 2-(10-bromoanthracen-9-ylmethyl)-5,5-dimethyl-2λ 5 -1,3,2-dioxaphosphinan-2-one ( 22). Reaction of 12 with 4-chloro- or 4-nitrobenzaldehyde in the presence of sodium hydride affords the products, 9-(2-arylvinyl)anthracenes 23 and 24 in an uncommon Horner-Wadsworth-Emmons-type reaction. Compound 22 underwent the normal Horner-Wadsworth-Emmons reaction with benzaldehydes or ferrocenecarbaldehyde to afford disubstituted alkenes. One of these alkenes, ( E)-9-bromo-10-[2-(4-bromophenyl)vinyl]anthracene ( 26), undergoes Sonogashira coupling with terminal alkynes to afford the conjugated alkynes ( E)-9-bromo-10-[2-(4-ethynylphenyl)vinyl]anthracenes 30- 32 in moderate yields. X-ray crystal structures of 12- 15, 20, 23 and ( E)-9-bromo-10-[2-(4-methoxyphenyl)vinyl]anthracene ( 27) have been determined.

Novel fluorinated silane coupling agents with a biphenyl structure, C n F 2 n +1 (C 6 H 4 ) 2 CH 2 CH 2 Si(OCH 3 ) 3 ( n = 4, 6, and 8), were synthesized with the aim to improve the heat-resistance, oxidation-resistance, and acid-resistance of the surface modified with a common fluorinated silane coupling agent. Alcohols, Rf (C 6 H 4 ) 2 CH(OH)CH 3 , were obtained by reducing the intermediates, Rf (C 6 H 4 ) 2 COCH 3 , the products of the reaction of 4-acetyl-4′-bromobiphenyl with perfluoroalkyl iodides in the presence of copper powder. The reaction of the alcohols with phosphorus tribromide gave olefins, Rf (C 6 H 4 ) 2 CH CH 2 , which were then allowed to react with tetramethoxysilane in the presence of hexachloroplatinate(IV) catalyst to yield novel fluorinated silane coupling agents with a biphenyl structure. The coupling agents with four and six carbon atoms in their fluorocarbon chains were obtained as a colorless liquid while that with 8 carbon atoms was a white gel. Evaluations were made of the coupling agents using surfaces modified with them in terms of water contact angles, heat-resistance, oxidation-resistance, and acid-resistance. The agents behaved similarly to the conventional fluorinated silane coupling agents with respect to water contact angles, oxidation-resistance, and acid-resistance, whereas the former showed an extremely higher heat-resistance (up to 350 °C). In addition, C 6 H 5 C 6 H 4 CH 2 CH 2 Si(OCH 3 ) 3 and CH 3 (C 6 H 4 ) 2 CH 2 CH 2 Si(OCH 3 ) 3 with no fluoroalkyl group were synthesized and the heat-resistance of glass surfaces modified with these compounds was examined.

An expeditious synthesis of aryl substituted E‐homoallylic bromides has been accomplished by the cleavage of cyclopropylcarbinols with phosphorus tribromide.

Allylic alcohols 3 – 18 and 36 were efficiently isomerized to corresponding saturated carbonyls 19 – 34 and 37 in excellent yields under mild reaction conditions (5–9 min, 0 °C) using PBr 3 .

The investigation concerns the effect of a bulky substituent at the pyrrole nitrogen atom on the orientation and regioselectivity of pyrrole phosphorylation with phosphorus(III) halides. As shown, phosphorylation of N-iso-propylpyrrole with phosphorus tribromide or trichloride proceeds nonregioselectively at positions 2 and 3 but it is followed by the 2 3 migration of the dihalogenophosphine group which quantitatively yields the 3-isomer. N-tert-butylpyrrole is regioselectively phosphorylated with halogenophosphines at position 3. The tert-butyl substituent at the nitrogen atom does not preclude the binding of even two or three pyrrolyl residues to the phosphorus atom. The key compounds, 3-pyrrolyldihalogenophosphines, were isolated in a pure state, characterized and used to obtain a number of stable phosphorus(V) derivatives. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:599–604, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20158

A further member of 2,4,6-trialkyl-phenyl-phos-pholes, the ditertbutylmethylphenyl derivative (1c) was characterized by Bird index and by the sum of angles at the phosphorus atom to describe the flattening of the P-pyramid. Both numbers suggested a slight aromaticity. The reaction of arylphospholes with phosphorus tribromide was extended to phosphole 1c leading this occasion, after further steps, to the mixture of 3- and 2-substituted products (3c-1 and 3c-2, respectively). A triisopropylphenyl-2H-phosphole (4) formed by sigmatropic rearrangement was utilized in the preparation of new 1-phosphanorbornene derivatives, such as sulfide 6 and hemi-oxides 8-1 and 8-2. Further oxidation of the latter species (8-1 and 8-2) led to the decomposition of the dimeric structure (11). 4 could also be trapped by benzaldehyde to afford the oxaphosphanorbornene (10) as one diastereomer. Finally, the reversible formation of 2H-phosphole 4 from 1H-phosphole 1a at 150°C was proved. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:104–222, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20077

Novel 3 substituted 1,5-dihydro-2,4,3-benzodioxaphosphepine 3-oxides (5a–h) were synthesized by reacting 1,2-benzenedimethanol (1) with phosphorus tribromide in the presence of triethylamine at 0–30°C and subsequent reaction of the monobromide (2) with different Grignard reagents (3) at room temperature. The products (4) were converted to corresponding oxides 5a–i by oxidation with H2O2 at room temperature. The chemical structures of all the products were confirmed by analytical, IR and NMR (1H, 13C, and 31P) spectral data. Their antifungal and antibacterial activity is also evaluated. Most of these compounds exhibited moderate antimicrobial activity in the assay. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:572–575, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20154

The reaction of 1-(tri-tert-butylphenyl)phosphole (1) with phosphorus tribromide gave the 3-dibromophosphino intermediate (2) selectively that was useful in the synthesis of phosphonic amides 4, H-phosphinic amide 6 and H-phosphinates 8. A similar transformation of the 1-(triisopropylphenyl)phosphole (9) led to a 2-substitution furnishing phosphonic amides 12 or H-phosphinates 14. The phosphorylated phospholes (4, 6, 8) were tested as ligands of transition metal complexes in hydroformylation.

Phosphorylation of N-arylpyrroles with phosphorus tribromide proceeds regioselectively at the position 2 of the heterocyclic system. A 2-to-3 migration of the dibromophosphino group has been discovered, with its ease depending on the electronic nature of a substituent on the phenyl ring, solvent polarity, and the presence of pyridine hydrobromide in the reaction mixture. Further phosphorylation of 2- and 3-monophosphorylated N-arylpyrroles regioselectively involves the respective positions 4 and 5 of the heterocycle and is governed by the electron-acceptor effect of the phosphorus-containing substituent. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:223–228, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10012

A reaction of phosphorus tribromide with a compound containing two 2,5-dimethyl-1-arylpyrrolyl-3 residues bound through a phosphorus atom gave rise to a new phosphorus-containing heterocyclic system, 1,4-diphosphinine. The new products thus obtained have been characterized and described. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:46–52, 2002; DOI 10.1002/hc.1105

This study covers phosphorylation of heterocyclic analogues of N-methyldiphenylamine with phosphorus tribromide in pyridine solution. The reaction is found to proceed regioselectively in accordance with the orienting effect of the amino group. Mono and bis-phosphorylated derivatives of the heterocycles have been isolated and characterized. It is pointed out that the heterocyclic systems under study exhibit reduced reactivity in electrophilic phosphorylation as compared to N-methyldiphenylamine. The results of calculations by the PM3 method are reported for the starting molecules and their σ-complexes. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:652–657, 2001

Methodology has been developed for the general synthesis of optically active beta-amino acid N-carboxyanhydrides (beta-NCAs) through cyclization of N(beta)-Boc or N(beta)-Cbz beta-amino acids using phosphorus tribromide. The formation of beta-NCAs was confirmed by spectroscopy as well as an X-ray structural determination of beta-homoalanine-N-carboxyanhydride. The beta-NCA molecules could be polymerized in good yield to give optically active poly(beta-peptides) that adopt stable chiral conformations in solution. For example, helical oligo(L-beta-homophenylalanine) was synthesized by polymerization of L-beta-homophenylalanine-N-carboxyanhydride.

Oligocycles with a 7-thiabicyclo[2.2.1]hept-5-ene unit have been prepared stereoselectively by cycloaddition of thiophene S-oxides to alkenes and subsequent deoxygenation of the sulfoxy bridge of the cycloadducts with PBr3.

C-Phosphorylation of 2-thiazolylformamidines by phosphorus tribromide was studied. It was shown that the 1,3-diazabut-1-enyl (formamidine) substituent can be used as both an activating and protective group. 5-Phosphorylated thiazoles containing either a formamidine fragment or an amino group were obtained. Some properties of the compounds synthesized were studied.

Hydride reduction of a series of substituted cis,cis-2,4-diene-1,6-dioates 1 provided the corresponding 1,6-diols 2, most of which were converted to the 1,6-dibromides 3 with phosphorus tribromide. Reaction of a selection of these dibromides with primary alkylamines in the presence of sodium hydrogen carbonate provided a simple and mild synthesis of substituted dihydroazepines 4. The cleanest products were obtained with toluene-p-sulfonamide as the nitrogen source. Bis(dihydroazepines) 5 were also synthesised from diamines while hydrazine yielded a hydrazinium salt 6. Aniline could be induced to take part in the reaction in the presence of butyllithium furnishing a low yield of N-phenyldihydroazepines 8.

The heat of formation of PBr 2 + , 842.9±1.5 kJ/mol at 0 K, has been determined by the dissociative photoionization of the phosphorus tribromide by threshold photoelectron photoion coincidence spectroscopy (TPEPICO) technique. Also measured was the adiabatic ionization energy of the phosphorus tribromide, 9.35±0.02 eV, and the new value of the 0 K heat of formation of PBr 3 · + ion was determined, 787±2 kJ/mol. The performance of G2 and density functional theory calculations with four functionals, B3PW91, B3P86, B3LYP, and BLYP in characterizing the ionization energy of PBr 3 and the appearance energy of the fragment PBr 2 + ion was examined.

1,2,3-diazaphospholines of new type containing an enamine residue, conjugated with the diazaphospholine cycle, were synthesized by phosphorylation of N,N-dimethyl- and N-substituted hydrazones of ω...

Depending on the reaction conditions, the condensation of triphenylphosphonium bis(trimethylsilyl)methylide 1 with phosphorus trichloride and phosphorus tribromide gives the cyclic trimers (Ph3P=CP-X)3, X = Cl, Br, trihalo-tris(triphenylphosphoranediyl)-1,3,5- triphosphinanes 3 and 5. In solution the compounds dissociate to give the ionic forms 4 and 6 which rapidly exchange the halide between the halophosphine and the phosphenium moieties. The exchange is slowed down when the halide ion is replaced by a tosylate ion. Substitution of the covalent chloride of 4 for diphenylphosphino groups gives again an ionic product 10, while the introduction of a morpholino group as well as the replacement of all chloride by triflate give dicationic compounds 12 and 13. Reaction of 3 with gallium trichloride finally leads to the tris(triphenylphosphonio)-1,3,5-triphosphinine trication as a major equilibrium participant.

An achiral (3) and two chiral pyridine-based macrobicyclic clefts (4 and 5) have been prepared by treating 2,6-bis[[2',6'-bis(bromomethyl)-4'-methylphenoxy]methyl]pyridine (2) with the appropriate achiral and chiral glycols. Starting 2 was prepared by first treating 2,6-bis(hydroxymethyl)-4-methylphenol with 2,6-[(tosyloxy)methyl]pyridine followed by phosphorus tribromide. Achiral macrobicyclic cleft 3 formed a complex at 25 degrees C in 50% CH(3)OH/50% CHCl(3) (v/v) with a primary ammonium salt (log K = 3.15) as evidenced by a significant change in the (1)H NMR spectrum. Highly organized (S,S,S,S)-4, prepared by treating 2 with (1S,5S)-3-oxapentane-1,5-diol, exhibited recognition at 25 degrees C in 20% C(2)H(5)OH/80% 1,2-C(2)H(4)Cl(2) (v/v) for the (S)-enantiomer of alpha-(1-naphthyl)ethylammonium perchlorate (NapEt) over its (R)-form (Delta log K = 0.85). This high recognition factor probably reflects an increase in molecular rigidity by the introduction of a second macro ring on the monocyclic pyridinocrown ligand.

Phosphorus trichloride in a basic medium is a convenient reagent for the direct C-phosphorylation of electron-rich aromatic heterocycles. The compounds obtained can be used for the synthesis of various types of heteroaryl and diheteroaryl derivatives of tri- and pentavalent phosphorus. © 1995 John Wiley & Sons, Inc.

The reaction of 2-methylbenzofuran and 2,3-dihydro-2-methylene-1,4-benzodioxin with phosphorus tribromide in alkaline media was used to produce the corresponding dibromophosphines, and other phosphorylated derivatives of these heterocyclics were produced on the basis of them.

The (2+1) resonance‐enhanced multiphoton ionization spectrum of phosphorus atoms is reported for the wavelength range 300–317 nm. Atomic phosphorus is formed by multiphoton photodissociation of phosphorus tribromide vapor. Photoelectron spectroscopy conducted at phosphorus ionization resonances produces pure populations of P+(3PJ) and P+(1D2) ions. Production of a mixture of phosphorus ionic states indicates a clear propensity to preserve the ion core electron configuration upon ionization of phosphorus. Four spin‐changing transitions are assigned supported by photoelectron spectral data.

The reaction of 2-alkyl-3-(trimethylsilyl)oxiranes (1a or 1b) with anions generated from alkyl phenyl sulfones (2a-f) followed by hydrolysis affords sec-alkyl alcohols (3-7). An analogous reaction in the presence of BF 3 .Et 2 O affords adducts (8-11). Treatment of (8-11) with NaOH under phase-transfer conditions affords stereospecifically the corresponding allylic alcohols (4a-5c). Reaction of oxirane (1a) with anions derived from sterically hindered sulfones (2e) or (2f) in the presence of BF 3 .Et 2 O was investigated. Reaction of compounds (8), (9) with phosphorus tribromide in pyridine affords β,γ-unsaturated sulfones (19)