685-83-6Relevant academic research and scientific papers
The new diphosphanylphosphido complexes of tungsten(VI) and molybdenum(VI). Their synthesis, structures and properties
Wi?niewska,Grubba,Ponikiewski,Zauliczny,Pikies
, p. 10213 - 10222 (2018)
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.
Prolinol as a Chiral Auxiliary in Organophosphorus Chemistry
Kozio?, Anna E.,W?odarczyk, Adam
, p. 1931 - 1941 (2021/04/06)
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.
Hydrogen/Halogen Exchange of Phosphines for the Rapid Formation of Cyclopolyphosphines
Barrett, Adam N.,Woof, Callum R.,Goult, Christopher A.,Gasperini, Danila,Mahon, Mary F.,Webster, Ruth L.
supporting information, p. 16826 - 16833 (2021/11/04)
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.
Systematic Study of the Stereoelectronic Properties of Trifluoromethylated Triarylphosphines and the Correlation of their Behaviour as Ligands in the Rh-Catalysed Hydroformylation
Herrera, Daniel,Peral, Daniel,Cordón, Mercedes,Bayón, J. Carles
supporting information, p. 354 - 363 (2020/12/30)
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.
Reactivity of phospha-Wittig reagents towards NHCs and NHOs
Gupta, Priyanka,Siewert, Jan-Erik,Wellnitz, Tim,Fischer, Malte,Baumann, Wolgang,Beweries, Torsten,Hering-Junghans, Christian
supporting information, p. 1838 - 1844 (2021/02/16)
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
Ring-Opening Polymerization of Cyclic Phosphonates: Access to Inorganic Polymers with a PV-O Main Chain
Arz, Marius I.,Annibale, Vincent T.,Kelly, Nicole L.,Hanna, John V.,Manners, Ian
supporting information, p. 2894 - 2899 (2019/03/05)
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.
Chemo-, Regio-, and Enantioselective Rhodium-Catalyzed Allylation of Triazoles with Internal Alkynes and Terminal Allenes
Berthold, Dino,Breit, Bernhard
supporting information, p. 598 - 601 (2018/02/10)
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.
Ligand-controlled α- And β-arylation of acyclic N-boc amines
Millet, Anthony,Dailler, David,Larini, Paolo,Baudoin, Olivier
supporting information, p. 2678 - 2682 (2014/03/21)
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.
METHODS FOR PHOSPHINE OXIDE REDUCTION IN CATALYTIC WITTIG REACTIONS
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Page/Page column 50, (2014/09/29)
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.
Catalytic wittig reactions of semi- and nonstabilized ylides enabled by ylide tuning
Coyle, Emma E.,Doonan, Bryan J.,Holohan, Andrew J.,Walsh, Killian A.,Lavigne, Florie,Krenske, Elizabeth H.,O'Brien, Christopher J.
supporting information, p. 12907 - 12911 (2016/02/18)
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.
