- The new diphosphanylphosphido complexes of tungsten(VI) and molybdenum(VI). Their synthesis, structures and properties
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We report on the reactivity of R2P-P(Li)-PR′2 (R = tBu, iPr, R′ = NEt2, iPr) towards diimido complexes [(dippN)2MCl2·dme] (M = Mo, W and dipp = 2,6-iPr2C6H3). A series of new complexes with diphosphanylphosphido ligands R2P-P-PR′2 were isolated. The solid-state structures of [(dippN)2M(Cl)(1,2-η-iPr2P-P-PiPr2)] (2Mo and 2W) and [(dippN)2M(Cl){1,2-η-tBu2P-P-P(NEt2)2}] (3Mo and 3W) were established by single-crystal X-ray diffraction analysis and indicate a side-on geometry of the R2P-P-PR′2 moiety. 3W and 3Mo are the first triphosphorus complexes with the amido ligand NEt2 on the P atom. [(dippN)2M(Cl)(1,2-η-tBu2P-P-PtBu2)] (1Mo and 1W) and 3Mo and 3W display similar side-on geometry in solution and in the solid state. By contrast, 2Mo and 2W reveal a dynamic behavior in solution. For the first time, the reactivity of diphosphanylphosphido complexes towards different nucleophiles was studied. The complexes react with the phosphorus nucleophile Ph2PLi, yielding phosphanylphosphinidene complexes [(dippN)2M(Cl)(η2-P-PR2)]? Li+ (M = Mo, W) together with related diphosphanes R′2P-PPh2. Carbon nucleophile MeLi does not yield [(dippN)2M(Cl)(η2-P-PR2)]? Li+ but substitutes a Cl ligand at the metal center. Moreover, we compare the coordination of the R2P-P-PR′2 moiety to different metal centers based on DFT methods.
- Wi?niewska,Grubba,Ponikiewski,Zauliczny,Pikies
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Read Online
- Prolinol as a Chiral Auxiliary in Organophosphorus Chemistry
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Several strategies for the development of the synthesis of P-chiral organophosphorus compounds with (L)-prolinol as a source of chirality have been examined. A reaction of L-prolinol with a set of different alkyl/arylphosphonous acid diamides led in most of the cases to the quantitative formation of the appropriate bicyclic oxazaphospholidines with complete diastereo and enantioselectivity. The latter were reacted with BH3 complex and the formed borane analogues were submitted to structural modifications leading to tertiary phosphine-boranes. Additionally, the effectiveness of oxazaphospholidines as ligands in transition metal asymmetric catalysis has been tested in hydrogenation of dehydroaminoacid esters and imine.
- Kozio?, Anna E.,W?odarczyk, Adam
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p. 1931 - 1941
(2021/04/06)
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- Hydrogen/Halogen Exchange of Phosphines for the Rapid Formation of Cyclopolyphosphines
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The hydrogen/halogen exchange of phosphines has been exploited to establish a truly useable substrate scope and straightforward methodology for the formation of cyclopolyphosphines. Starting from a single dichlorophosphine, a sacrificial proton "donor phosphine"makes the rapid, mild synthesis of cyclopolyphosphines possible: reactions are complete within 10 min at room temperature. Novel (aryl)cyclopentaphosphines (ArP)5 have been formed in good conversion, with the crystal structures presented. The use of catalytic quantities of iron(III) acetylacetonate provides significant improvements in conversion in the context of diphosphine (Ar2P)2 and alkyl-substituted cyclotetra- or cyclopentaphosphine ((AlkylP)n, where n = 4 or 5) formation. Both iron-free and iron-mediated reactions show high levels of selectivity for one specific ring size. Finally, investigations into the reactivity of Fe(acac)3 suggest that the iron species is acting as a sink for the hydrochloric acid byproduct of the reaction.
- Barrett, Adam N.,Woof, Callum R.,Goult, Christopher A.,Gasperini, Danila,Mahon, Mary F.,Webster, Ruth L.
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supporting information
p. 16826 - 16833
(2021/11/04)
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- Systematic Study of the Stereoelectronic Properties of Trifluoromethylated Triarylphosphines and the Correlation of their Behaviour as Ligands in the Rh-Catalysed Hydroformylation
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The stereoelectronic properties of a series of trifluoromethylated aromatic phosphines have been studied using different approaches. The σ-donating capability has been evaluated by nuclear magnetic resonance (NMR) spectroscopy of the selenide derivatives and the protonated form of the different trifluoromethylated phosphines. The coupling constants between phosphorous and selenium (1JSeP) and phosphorous and hydrogen (1JHP) can be predicted by empirical equations and correlate the basicity of the phosphines with the number and relative position of trifluoromethyl groups. In contrast, the π-acceptor character of the ligands has been evaluated by measuring the frequency of the CO vibration in the infrared (IR) spectra of the corresponding Vaska type iridium complexes ([IrCl(CO)(PAr3)2], PAr3=triarylphosphine). Moreover, the correlation between the electronic properties and the performance of these phosphines as ligands in the rhodium-catalysed hydroformylation of 1-octene has been established. Phosphines with the lowest basicity, that are those with the highest number of trifluoromethyl groups, gave rise to more active catalytic systems.
- Herrera, Daniel,Peral, Daniel,Cordón, Mercedes,Bayón, J. Carles
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supporting information
p. 354 - 363
(2020/12/30)
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- Reactivity of phospha-Wittig reagents towards NHCs and NHOs
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Phospha-Wittig reagents, RPPMe3(R = Mes* 2,4,6-tBu3-C6H2;MesTer 2,6-(2,4,6-Me3C6H2)-C6H3;DipTer 2,6-(2,6-iPr2C6H
- Gupta, Priyanka,Siewert, Jan-Erik,Wellnitz, Tim,Fischer, Malte,Baumann, Wolgang,Beweries, Torsten,Hering-Junghans, Christian
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supporting information
p. 1838 - 1844
(2021/02/16)
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- Ring-Opening Polymerization of Cyclic Phosphonates: Access to Inorganic Polymers with a PV-O Main Chain
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We describe a new class of inorganic polymeric materials featuring a main chain consisting of PV-O bonds and aryl side groups, which was obtained with >70 repeat units by ring-opening polymerization of cyclic phosphonates. This monomer-polymer system was found to be dynamic in solution enabling selective depolymerization under dilute conditions, which can be tuned by varying the substituents. The polymers show high thermal stability to weight loss and can be easily fabricated into self-standing thin films. Structural characterizations of the cyclic 6-and 12-membered ring precursors are also described.
- Arz, Marius I.,Annibale, Vincent T.,Kelly, Nicole L.,Hanna, John V.,Manners, Ian
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supporting information
p. 2894 - 2899
(2019/03/05)
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- Chemo-, Regio-, and Enantioselective Rhodium-Catalyzed Allylation of Triazoles with Internal Alkynes and Terminal Allenes
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The rhodium-catalyzed asymmetric N1-selective and regioselective coupling of triazole derivatives with internal alkynes and terminal allenes gives access to secondary and tertiary allylic triazoles in very good enantioselectivities. For this process, three new members of the JosPOphos ligand family have been prepared and employed in catalysis. The optimized reaction conditions enable the coupling of triazoles with internal alkynes as well as with allenes, displaying a high tolerance for functional groups. A gram scale reaction provided N1-allyltriazole, which was subjected to various transformations highlighting synthetic utility.
- Berthold, Dino,Breit, Bernhard
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supporting information
p. 598 - 601
(2018/02/10)
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- Ligand-controlled α- And β-arylation of acyclic N-boc amines
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The palladium-catalyzed ligand-controlled arylation of α-zincated acyclic amines, obtained by directed α-lithiation and transmetalation, is described. Whereas PtBu3 gave rise to α-arylated Boc-protected amines, more flexible N-phenylazole-based phosphine ligands induced major β-arylation through migrative cross-coupling. All manner of control: The arylation of α-zincated acyclic Boc-protected amines was selectively performed at the α- or β-position in a ligand-controlled manner. α-Arylation occurs by direct reductive elimination of the α-palladated intermediate whereas β-arylation involves palladium migration along the alkyl chain. Boc=tert-butoxycarbonyl.
- Millet, Anthony,Dailler, David,Larini, Paolo,Baudoin, Olivier
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supporting information
p. 2678 - 2682
(2014/03/21)
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- METHODS FOR PHOSPHINE OXIDE REDUCTION IN CATALYTIC WITTIG REACTIONS
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A method for increasing the rate of phosphine oxide reduction, preferably during a Wittig reaction comprising use of an acid additive is provided. A room temperature catalytic Wittig reaction (CWR) the rate of reduction of the phosphine oxide is increased due to the addition of the acid additive is described. Furthermore, the extension of the CWR to semi-stabilized and non-stabilized ylides has been accomplished by utilization of a masked base and/or ylide-tuning.
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Page/Page column 50
(2014/09/29)
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- Catalytic wittig reactions of semi- and nonstabilized ylides enabled by ylide tuning
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The first examples of catalytic Wittig reactions with semistabilized and nonstabilized ylides are reported. These reactions were enabled by utilization of a masked base, sodium tert-butyl carbonate, and/or ylide tuning. The acidity of the ylide-forming proton was tuned by varying the electron density at the phosphorus center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement of E selectivity up to >95:5, E/Z. Time for a tune up: Catalytic Wittig reactions with semi- and nonstabilized ylides were enabled by use of a masked base (NaOCO2tBu) and/or ylide tuning. The acidity of the ylide-forming proton was tuned by varying the electron density at the P center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement of E selectivity.
- Coyle, Emma E.,Doonan, Bryan J.,Holohan, Andrew J.,Walsh, Killian A.,Lavigne, Florie,Krenske, Elizabeth H.,O'Brien, Christopher J.
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supporting information
p. 12907 - 12911
(2016/02/18)
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- Intermolecular mizoroki-heck reaction of aliphatic olefins with high selectivity for substitution at the internal position
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New ligand for old reaction: The title reaction of aryltriflates with aliphatic olefins leads to substitution at the internal position with high selectivity. The ratio of the desired isomer (shown in the scheme) to the sum of all other isomers is generall
- Qin, Liena,Ren, Xinfeng,Lu, Yunpeng,Li, Yongxin,Zhou, Jianrong
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supporting information; experimental part
p. 5915 - 5919
(2012/07/30)
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- Mechanistic investigation of the nickel-catalyzed Suzuki reaction of N, O-acetals: Evidence for boronic acid assisted oxidative addition and an iminium activation pathway
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The mechanism of a recently reported Suzuki coupling reaction of quinoline-derived allylic N,O-acetals has been studied using a combination of structural, stereochemical, and kinetic isotope effect experiments. The data indicate that C-O activation is fac
- Sylvester, Kevin T.,Wu, Kevin,Doyle, Abigail G.
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supporting information
p. 16967 - 16970,4
(2012/12/12)
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- Mechanistic investigation of the nickel-catalyzed Suzuki reaction of N, O-acetals: Evidence for boronic acid assisted oxidative addition and an iminium activation pathway
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The mechanism of a recently reported Suzuki coupling reaction of quinoline-derived allylic N,O-acetals has been studied using a combination of structural, stereochemical, and kinetic isotope effect experiments. The data indicate that C-O activation is fac
- Sylvester, Kevin T.,Wu, Kevin,Doyle, Abigail G.
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supporting information
p. 16967 - 16970
(2013/01/15)
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- ETHYLENE TRIMERIZATION CATALYSTS COMPRISING P-N-P LIGANDS AND THEIR USE
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A new P-N-P ligand having the general formula (Ph1)(Ph2)P-N-P(Ph3)(Ph4) R2 wherein each Of Ph1, Ph2, Ph3 and Ph4 is a phenyl group bonded to a phosphorus gr
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Page/Page column 20
(2010/04/27)
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- Selective synthesis of chlorophosphoramidites using ionic liquids
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A range of chlorophosphoramidites have been prepared in ionic liquids and compared with material synthesised in molecular solvents. Through the use of ionic liquids as reaction media the moisture sensitivity and impurity issues hampering existing traditio
- Amigues, Eric J.,Hardacre, Christopher,Keane, Gillian,Migaud, Marie E.,Norman, Sarah E.,Pitner, William R.
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scheme or table
p. 1391 - 1396
(2010/05/18)
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- Structure-based rationale for selectivity in the asymmetric allylic alkylation of cycloalkenyl esters employing the Trost 'Standard Ligand' (TSL): Isolation, analysis and alkylation of the monomeric form of the cationic η3-cyclohexenyl complex [(η3-c-C6H 9)Pd(TSL)]+
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The solution-phase structures of the monomeric forms of the cationic Pd-η3-allyl and Pd-η3-cyclohexenyl complexes [Pd(R,R)-1(η3-C3H5)]+ (7 +) and [Pd(R,R)-1(η3-C6H9)] + (8+) bearing the trans-cyclohexylenediamine-based Trost 'Standard Ligand' (R,R)-1 have been elucidated by NMR, isotopic labeling and computation. In both complexes, (R,R)-1 is found to adopt a C1-symmetric conformation, leading to a concave shape in the 13-membered chelate in which one amide group in the chiral scaffold projects its NH unit out of the concave surface in close vicinity to one allyl terminus. The adjacent amide has a reversed orientation and projects its carbonyl group out of the concave face in the vicinity of the opposite allyl terminus. Stoichiometric and catalytic asymmetric alkylations of [8+][X-] by MCHE2 (E = ester, M = 'escort' counterion, X = Pd allyl counterion) show the same selectivities and trends as have been reported for in situ-generated catalysts, and a new model for the enantioselectivity has been explored computationally. Three factors are found to govern the regioselectivity (pro-S vs pro-R) of attack of nucleophiles on the η3-C6H9 ring in 8+ and thus the ee of the alkylation product: (i) a pro-R torquoselective bias is induced by steric interaction of the η3-C6H9 moiety with one phenyl ring of the ligand; (ii) pro-S delivery of the nucleophile can be facilitated by hydrogen-bonding with the concave orientated amide N-H; and (iii) pro-R delivery of the nucleophile can be facilitated by escort ion (M) binding to the concave orientated amide carbonyl. The latter two opposing interactions lead to the selectivity of the alkylation being sensitive to the identities of X- and M+. The generation of 8+ from cyclohexenyl ester substrate has also been explored computationally. The concave orientated amide N-H is able to activate the leaving group of the allylic ester by hydrogen bonding to its carbonyl group. However, this interaction is only feasible for the (S)-enantiomer of substrate, leading to the prediction of a powerful kinetic resolution (kS ? kR), as is found experimentally. This new model involving two regiochemically distinct (NH) and (CO) locations for nucleofuge or nucleophile binding, may prove of broad utility for the interpretation of the selectivity in asymmetric allylic alkylation reactions catalyzed by Pd complexes of (R,R)-1 and related ligands.
- Butts, Craig P.,Filali, Emane,Lloyd-Jones, Guy C.,Norrby, Per-Ola,Sale, David A.,Schramm, York
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supporting information; experimental part
p. 9945 - 9957
(2009/12/08)
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- CHIRAL PHOSPHORUS COMPOUNDS
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The present invention provides P-chiral compounds of general formula (II) and (III): wherein at least one of R21, R25, R26 and R30 is independently selected from C1-4 alkyl, CF3, C1-4 alkoxy, phenyl and benzyloxy and the remaining substituents selected from R21, R25, R26 and R30 are hydrogen; at least one of R22, R24, R27 and R29 are independently selected from C1-4 alkyl, CF3, C1-4 alkoxy, phenyl and benzyloxy and the remaining substituents selected from R22, R24, R27 and R29 are hydrogen; and R23 and R28 are independently selected from hydrogen, C1-4 alkyl, CF3, C1-4 alkoxy, phenyl and benzyloxy; Formula (III): wherein at least one of R21, R25, R26 and R30 is independently selected from phenyl and benzyloxy and the remaining substituents selected from R21, R25, R26 and R30 are hydrogen; and R22, R23, R24, R27, R28 and R29 are independently selected from hydrogen, C1-4 alkyl, CF3, C1-4 alkoxy, phenyl and benzyloxy.wherein at least one of R21, R25, R26 and R30 is independently selected from phenyl and benzyloxy and the remaining substituents selected from R21, R25, R26 and R30 are hydrogen; and R22, R23, R24, R27, R28 and R29 are independently selected from hydrogen, C1-4 alkyl, CF3, C1-4 alkoxy, phenyl and benzyloxy.
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Page/Page column 27
(2008/12/04)
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- IONIC LIQUID CONTAINING PHOSPHONIUM CATION HAVING P-N BOND AND METHOD FOR PRODUCING SAME
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An ionic liquid which contains an organic matter represented by the following general formula (1) as a cation component. The ionic liquid is stably in a liquid state over a wide temperature range and is excellent in electrochemical stability. The ionic liquid is advantageously used for applications such as electric power storage devices, lithium secondary batteries, electrical double layer capacitors, dye-sensitized solar cells, fuel cells, and reaction solvents.
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Page/Page column 8
(2008/12/07)
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- Molecular studies of the initiation and termination steps of the anionic polymerization of P=C bonds
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The initiation and termination steps of the anionic polymerization of P=C bonds have been modeled. The initiation step was investigated through the stoichiometric reaction of MesP=CPh2 (1) with RLi (R = Me or n-Bu). In each case, the addition w
- Gillon, Bronwyn H.,Noonan, Kevin J.T.,Feldscher, Bastian,Wissenz, Jennifer M.,Kam, Zhi Ming,Hsieh, Tom,Kingsley, Justin J.,Bates, Joshua I.,Gates, Derek P.
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p. 1045 - 1052
(2008/09/16)
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- Novel palladium complexes employing mixed phosphine phosphonates and phosphine phosphinates as anionic chelating [P,O] ligands
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A route to various substituted phosphine phosphonic acid compounds of the general form Ar2PC6H4PO(OH)2 (Ar = Ph, o-MeC6H4, o-MeOC6H4) has been investigated. These comp
- Reisinger, Corinna M.,Nowack, Ruediger J.,Volkmer, Dirk,Rieger, Bernhard
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p. 272 - 278
(2007/10/03)
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- OPTICALLY ACTIVE PHOSPHITES AND PHOSPHORAMIDITES BEARING BIPHENOL SKELETONS WITH AXIAL CHIRALITY, AND THEIR USE IN CATALYTIC ASYMMETRIC REACTIONS
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Novel optically active ligands which are mondentate phosphites and phosphoramidites, and bidentate phosphites and phosphoramidites; optically active catalysts comprising a reaction mixture of the ligand and a transition metal or its compound; and processes of using the optically active catalysts to produce optically active compounds.
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Page/Page column 65-66
(2010/12/01)
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- Solid-phase chemical synthesis of phosphonoacetate and thiophosphonoacetate oligodeoxynucleotides
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Phosphonoacetate and thiophosphonoacetate oligodeoxynucleotides were prepared via a solid-phase synthesis strategy. Under Reformatsky reaction conditions, novel esterified acetic acid phosphinodiamidites were synthesized and condensed with appropriately protected 5′-O-(4, 4′-dimethoxytrityl)-2′-deoxynucleosides to yield 3′-O-phosphinoamidite reactive monomers. These synthons when activated with tetrazole were used with an automated DNA synthesizer to prepare phosphonoacetic acid modified internucleotide linkages on controlled pore glass. The phosphinoacetate coupling products were quantitatively oxidized at each step with (1S)-(+)-(10-camphorsulfonyl)oxaziridine or 3H-1,2-benzodithiol-3-one-1,1-dioxide to produce mixed sequence phosphonoacetate and thiophosphonoacetate oligodeoxynucleotides with an average per cycle coupling efficiency of greater than 97%. Completely deprotected, modified oligodeoxynucleotides were purified by reverse-phase HPLC and characterized by ion exchange HPLC, 31P NMR, and MALDI/TOF mass spectroscopy. Both analogues were stable toward hydrolysis with snake venom phosphodiesterase and stimulated RNase H1 activity.
- Dellinger, Douglas J.,Sheehan, David M.,Christensen, Nanna K.,Lindberg, James G.,Caruthers, Marvin H.
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p. 940 - 950
(2007/10/03)
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- Synthesis, characterization, and properties of the polyphosphinoboranes [RPH-BH2]n (R = Ph, iBu, p-nBuC6H4, p-dodecylC6H4): Inorganic Polymers with a phosphorus-boron backbone
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The polyphosphinoboranes [PhPH-BH2]n (1), [iBuPH-BH2]n (2), [(p-nBuCsH4)PH-BH2]nn (3), and [(p-dodecylC6H4)PH-BH2]n (4) were prepared from the corresponding phosphine-borane adducts RPH2·BH3 (R = Ph, iBu.p-nBuC6H4, p-dodecylC6H4) via a rhodium-catalyzed dehydrocoupling procedure at elevated temperatures (ca. 90-130°C). Samples of polymers 1 and 2 and the new materials 3 and 4 were characterized by multinuclear NMR spectroscopy, and the molecular weights were determined by light scattering methods in THF or CH2Cl2 solutions. The absolute weight-average molecular weight of 2 was determined by static light scattering and found to be Mw = 13 100, and values of Mw of ca. 20 000 were estimated for the sample of polymers 1 and the new material 3 using dynamic light scattering (DLS). The molecular weights of polymers 3 and 4 were also analyzed by gel permeation chromatography using polystyrene standards, and values up to Mw = ca. 80 000, Mn = ca. 10 000 were determined for 3 and Mw = ca. 168 000, Mn = ca. 12 000 for 4. The chemical stability of 1 in THF toward HNEt2 or nBu3P was demonstrated using NMR spectroscopy and DLS analysis, which indicated that no significant polymer degradation occurred. WAXS analysis of 1 and 3 showed that the polymers are amorphous. The glass transition temperatures (Tg) of polymers 2, 3, and 4 were analyzed by DSC and were detected at ca. 5, 8, and -1°C, respectively. TGA analysis on 1-3 revealed T5% values (temperature for which 5% or the weight is lost) of 240°C for 1 and ca. 150-160°C for 2 and 3. After heating to 1000°C, ceramic yields in the range of 35-80% were obtained. The high ceramic yield for 1 (75-80%) indicates that this material is of interest as a pyrolytic precursor to boron phosphide-based solid-state materials.
- Dorn, Hendrik,Rodezno, Jose M.,Brunnhoefer, Bjoern,Rivard, Eric,Massey, Jason A.,Manners, Ian
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p. 291 - 297
(2007/10/03)
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- REACTIONS OF 2-DIETHYLAMINO-5-METHYL-1,3,2-OXATHIAPHOSPHOLENE WITH PROTON-DONOR REAGENTS AND CHLOROPHOSPHINES
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The ethanolysis ond phenolysis of 2-diethylamino-5-methyl-1,3,2-oxathiaphospholene were studied.In the first case we observe the initial splitting of the endocyclic P-E bonds, and in the second case the replacement of the dialkylamino group by the phenoxy group, with the cyclic fragment retained.Similarly to the phenolysis, the phospholene reacts with hydrogen chloride and carboxylic acids. 2-Dialkylamino(alkoxy)-1,3,2-oxathiaphospholenes undergo exchange reactions with P(III) chlorides on heating.
- Burilov, A.R.,Nikolaeva, I.L.,Pudovik, M.A.
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p. 685 - 687
(2007/10/02)
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- FEATURES OF THE REACTION OF N-BENZOYL- AND N-PHOSPHINOYL-TRIFLUOROACETIMIDOYL CHLORIDES WITH PHOSPHORUS(III) AMIDES
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Reaction of N-substituted trifluoroacetimidoyl chlorides CF3C(Cl)=NX with P(III) amides leads to aminophosphonium salts CF3C+(NR2)3>=NX Cl-, which are stable in the solid state and decompose in solvents of low polarity to give amidines CF3C(NR2)=NX and aminochlorophosphines (R2N)nPCl(3-n).The stability of these salts decreases in the following series of X: PhC(O) > Cl2P(O) > (EtO)2P(O), and of R: Et > Me; and increases with increase in solvent polarity.Reaction of imidoyl chlorides with o-phenylene diethylphosphoramidite depends on the nature of the N-substituent: with X = PhC(O) -cycloaddition is realized, leading to spirophosphoranes, while with X = P(O)Cl2 or P(O)(OEt)2 amination occurs, leading to formation of amidines and aminochlorophosphines.In the reactions of imidoyl chlorides with Ph3P the phosphorane Ph3PF2 was detected, which was probably formed via halogenophilic attack.
- Onys'ko, P. P.,Kolodka, T. V.,Kolotilo, N. V.,Kudryavtsev, A. A.,Sinitsa, A. D.
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p. 359 - 364
(2007/10/02)
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- ON DERIVATISATION REACTIONS OF 2-CHLORO-3-DICHLOROPHOSPHANYL-1,3,2-OXAZAPHOSPHORINANE
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Derivatisation reactions of 2-chloro-3-dichlorophosphanyl-1,3,2-oxazaphosphorinane 1b with protic nucleophiles like HNEt2, C2H5OH, CH3OH and the Franz-reagent NEt33HF forming the substituted N-phosphanylphosphorinanes 2-10 are described.Furthermore the temperature dependence of the 2JPNP-coupling constant of 2-chloro-3-dichlorophosphanyl-1,3,2-oxazaphosphorinane 1b and 2-diethylamino-3-bis(diethylamino)phosphanyl-1,3,2-oxazaphoshorinane 2 in a range from 203 K to 353 K was investigated.Key words: N-phosphanylphosphorinanes; 2-chloro-3-dichlorophosphanyl-1,3,2-oxazaphosphorinane; temperature dependence of 2JPNP.
- Mundt, Cornelia,Riesel, Lothar
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p. 169 - 178
(2007/10/02)
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- An Improved Synthesis of the Strong Base P(MeNCH2CH2)3N
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The proazaohosphatrane P(MeNCH2CH2)3N is synthesized in high yield from (HMeNCH2CH2)3N and ClP(NEt2)2.The last compound is synthesized from inexpensive PCl3 and HNEt2. Key Words: strong non-ionic base; proazaphosphatrane; high yield synthesis
- Tang, Jian-sheng,Verkade, John G.
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p. 2903 - 2904
(2007/10/02)
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- Catalytic Enantioselective Hydrosilylation of Aromatic Ketones Using Rhodium Complexes of TADDOL-Derived Cyclic Phosphonites and Phosphites
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Cyclic phosphonites and phosphites 2-4 are readily available from Cl2PR and (R,R)- or (S,S)-α,α,α',α'-tetraaryl-1,3-dioxolane-4,5-dimethanols (=TADDOLs 1, which, in turn, are only two steps away from tartrate); the X-ray crystal structure of one representative, the phenyl phosphonite 2b, was determined.Five previously described and six new ones of the chiral P derivatives were tested as ligands for Rh1- and Pd0-catalyzed reactions such as hydrocarbonylations, hydroborations, and hydrosilylations of C=C bonds; while the resulting catalysts were highly active and regioselective, they did not lead to useful enantiomer enrichment in the products (Scheme 1).In contrast, hydrosilylation of phenyl and 2-naphthyl methyl or ethyl ketone by Ph2SiH2 (1.2 equiv.) gave, after desilylation, the corresponding secondary alcohols of (R)-configuration with up to 87percent ee in the presence of 0.1 equiv. of the penta(2-naphthyl)-substituted phosphonite 3d and 0.02 mol-equiv. of Rh (Table 1 ).
- Sakaki, Jun-ichi,Schweizer, W. Bernd,Seebach, Dieter
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p. 2654 - 2665
(2007/10/02)
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- Phenylfluorophosphoranes: axial-equatorial fluorine exchange in RC6H4PF3H and intermolecular exchange in the PhPF2(H)OMe-MeOH-base system
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Activation parameters for axial-equatorial fluorine exchange in arylfluorophophoranes PC6H4PF3H, where R = o-CF3, m-CF3, m-CH3, were studied by the dynamic nmr technique. Δ G298(excit.) varied between 53 and 56 kJ mol-1.The synthesis of difluoromethoxyphenylphosphorane, PhPF2(H)OMe, from PhPF2 and MeOH is catalyzed by small amounts of Et3N, pyridine, PhPF3H, or HF.Rapid intermolecular ligand exchange occurs in PhPF2(H)OMe after addition of methanol and a base such as triethylamine or pyridine.Under these conditions, exchange of fluorine, hydrogen, and methoxy ligands occurs, as shown by 1H, 19F, and 31P nmr.From a line shape analysis of the 31P nmr spectrum, the rate of P-F cleavage was found to be first order (1.17 +/- 0.2) in Et3N concentration, with Δ G(excit.)298 = 50 kJ mol-1 and Δ S (excit.) = -67 J mol-1 deg-1.An equilibrium constant of 1.8 at 25 deg C was found for the reaction of PhPF2(H)OMe with PhPF2.
- Kruczynski, Leonard J.,Lemire, Alberta E.,Marat, Kirk,Janzen, Alexander F.
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p. 488 - 491
(2007/10/02)
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- OBERFLAECHEN-REAKTIONEN 15 Heterogene Dechlorierungen von Phosphorchloriden (X)PCl3 und R-PCl2 an , , x/TiO2> und sowie spektroskopische Evidenz fuer das Entstehen von Diphospha-dicyan PC-CP aus Cl2P-CC-PCl2
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Stimulated by the successful generation of unsaturated molecules with low-coordinated phosphorus centers by heterogeneous surface dechlorination, Cl2P-CC-PCl2 is synthesized and characterized by PE and mass spectra.In addition, curls, wool and catalysts x/TiO2> or are tested as potential dechlorinating agents for phosphorus halides like OPCl3, SPCl3, H3C-PCl2, H5C2-PCl2, (H3C)3C-PCl2 or H5C6-PCl2 in a gasflow reactor under reduced pressure and yield, inter alia, the following representative results: due to the thermodynamically favored formation of , or at the Mg surface, P4 is the only gaseous product identified from reactions of OPCl3 and SPCl3 with metal at higher temperatures.On the contrary, passing H3C-PCl2 at 600K over yields a reaction mixture containing P(CH3)3, (H3C)2P-P(CH3)2 (H3C-P)5 and CH4, which suggests an intermediate formation of surface phosphinidenes Mg>.Analogously, the pentamer (H3C-H2C-P)5 can be isolated from ethyldichlorophosphane.Reaction of the evaporated diphospha-cyanogen precursor Cl2P-C-PCl2 with the catalyst produces predominantly PCl3, and P4, but PE and mass spectra provide evidence that also minor amounts of the hitherto unknown molecule PC-CP are formed.
- Bock, H.,Bankmann, M.
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p. 167 - 191
(2007/10/02)
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- Synthesis of Triphenylphosphane-en-ynes and Phosphindoles as well as X-Ray Analyses of two Phosphindoles
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By means of aminochlorophenylphosphanes triphenylphosphanes are prepared, in which the o-positions are optionally substituted by trans-phenylethenyl and phenylethinyl groups (4a - c and 5a - c).Surprisingly, the intermediate chlorophosphanes 3a and c can
- Butters, Thomas,Winter, Werner
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p. 990 - 1002
(2007/10/02)
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- Bis(dialkylamino)phosphines
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Reactions of LiAlH4 with sufficiently sterically hindered (R2N)2PCl derivatives (R = isopropyl and ethyl but not methyl) in diethylether give the corresponding (R2N)2PH derivatives as air-sensitive, vacuum-destillable liquids.Analogous reactions of LiAlH4 with sufficiently sterically hindered heterocycles (CH2)n(NR)2PCl (R = tert-butyl, n = 2 and 3; R not methyl, n not 2) give the corresponding heterocyclic PH derivatives (CH2)n(NR)2PH.The dialkylamino groups in (R2N)2PH undergo successive alcoholysis with the alcohols R'OH (R' = methyl, ethyl, isopropyl, andtert-butyl) to form (R2N)(R'O)PH and (R'O)2PH derivatives, which are identified by their phosphorus-31 NMR spectra.The derivatives (R2N)(R'O)PH (R = isopropyl; R'= methyl, ethyl, isopropyl, and tert-butyl) can be isolated by vacuum distillation as air-sensitive liquids, but the derivatives (R'O)2PH generally decompose upon attempted vacuum distillation.The (R2N)2PH derivatives undergo base-catalyzed addition to (R2N)2PCH=CH2 to give the corresponding diphosphines (R2N)2PCH2CH2P(NR2)2, provided that the R2N groups are not too bulky .The mass spectra and NMR spectra of the new organophosphorus compounds are described.
- King, R.B.,Sundaram, P.M.
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p. 1784 - 1789
(2007/10/02)
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- SOME EXCHANGE REACTION IN THE SERIES OF THIODERIVATIVE ACIDS OF TRIVALENT PHOPHORUS
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1.It was shown that reactions of thioesters of acids of trivalent phosphorus with PIII acid halides proceed with substitution of the thioalkyl groups. 2.Thiosphosphorous acid chlorides interact readily with aminophosphites, leading to products of exchange of chlorine atoms for amide groups.
- Sinyashin, O. G.,Ofitserov, E. N.,Batyeva, E. S.,Pudovik, A. N.
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p. 2078 - 2080
(2007/10/02)
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- NMR study (1H, 13C and 31P) of the nPX3-n compounds (X=Cl, C2H5; n=0,1,2,3)
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1H, 13C and 31P NMR data of the compounds nPX3-n (X=Cl, C2H5; n=0,1,2,3) are reported.While the 1H and 13C resonances from the PEt moiety rather follow the electron-withdrawing effect of the -NEt substituent, 1H and 13C chemical shift data from the -NEt2 moiety reveal a quite important shift contribution originating from sterically induced polarization of the C-H bonds. 31P chemical shift data are interpreted in terms of inductive effects but the anomalous diamagnetic shift deviation from linearity for X=Cl suggests a minor contribution from multiple bonding.The general trend observed in the 31P-couplings is quite straightforward and can be qualitatively explained by Bent's rule.
- Linthoudt, J. P. van,Berghe, E. V. van den,Kelen, G. P. van der
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p. 315 - 320
(2007/10/02)
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