- A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics
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The kinetics of quinuclidine displacement of BH3 from a wide range of Lewis base borane adducts have been measured. Parameterization of these rates has enabled the development of a nucleofugality scale (NFB), shown to quantify and predict the leaving group ability of a range of other Lewis bases. Additivity observed across a number of series R′3-nRnX (X = P, N; R′ = aryl, alkyl) has allowed the formulation of related substituent parameters (nfPB, nfAB), providing a means of calculating NFB values for a range of Lewis bases that extends far beyond those experimentally derived. The utility of the nucleofugality parameter is explored by the correlation of the substituent parameter nfPB with the hydrolyses rates of a series of alkyl and aryl MIDA boronates under neutral conditions. This has allowed the identification of MIDA boronates with heteroatoms proximal to the reacting center, showing unusual kinetic lability or stability to hydrolysis.
- García-Domínguez, Andrés,Gonzalez, Jorge A.,Leach, Andrew G.,Lloyd-Jones, Guy C.,Nichol, Gary S.,Taylor, Nicholas P.
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supporting information
(2022/01/04)
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- Method for synthesizing tert-butyl diphenylphosphine compound
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The invention discloses a method for synthesizing a tert-butyl diphenylphosphine compound, and belongs to the field of organic synthesis. The method comprises the following step: in an anhydrous and oxygen-free atmosphere, tert-butyl alcohol is taken as a raw material and reacts with diphenylphosphine under the action of a catalyst to generate tert-butyl diphenylphosphine. Compared with the prior art, the method has the advantages of mild reaction conditions, simple operation, high yield, simple and easily available raw materials and reduced production cost, and is suitable for industrial production.
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Paragraph 0006; 0014-0017
(2021/07/14)
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- Versatile Visible-Light-Driven Synthesis of Asymmetrical Phosphines and Phosphonium Salts
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Asymmetrically substituted tertiary phosphines and quaternary phosphonium salts are used extensively in applications throughout industry and academia. Despite their significance, classical methods to synthesize such compounds often demand either harsh reaction conditions, prefunctionalization of starting materials, highly sensitive organometallic reagents, or expensive transition-metal catalysts. Mild, practical methods thus remain elusive, despite being of great current interest. Herein, we describe a visible-light-driven method to form these products from secondary and primary phosphines. Using an inexpensive organic photocatalyst and blue-light irradiation, arylphosphines can be both alkylated and arylated using commercially available organohalides. In addition, the same organocatalyst can be used to transform white phosphorus (P4) directly into symmetrical aryl phosphines and phosphonium salts in a single reaction step, which has previously only been possible using precious metal catalysis.
- Arockiam, Percia Beatrice,Lennert, Ulrich,Graf, Christina,Rothfelder, Robin,Scott, Daniel J.,Fischer, Tillmann G.,Zeitler, Kirsten,Wolf, Robert
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supporting information
p. 16374 - 16382
(2020/11/03)
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- Rational design of a second generation catalyst for preparation of allylsilanes using the silyl-Heck reaction
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Using rational ligand design, we have developed of a second-generation ligand, bis(3,5-di-tert-butylphenyl)(tert-butyl)phosphine, for the preparation of allylsilanes using the palladium-catalyzed silyl-Heck reaction. This new ligand provides nearly complete suppression of starting material alkene isomerization that was observed with our first-generation catalyst, providing vastly improved yields of allylsilanes from simple alkene starting materials. The studies quantifying the electronic and steric properties of the new ligand are described. Finally, we report an X-ray crystal structure of a palladium complex resulting from the oxidative addition of Me3SiI using an analogous ligand that provides significant insight into the nature of the catalytic system.
- McAtee, Jesse R.,Yap, Glenn P. A.,Watson, Donald A.
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supporting information
p. 10166 - 10172
(2014/08/05)
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- Ambident PCN heterocycles: N- and P-phosphanylation of lithium 1,3-benzazaphospholides
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Synthetic and structural aspects of the phosphanylation of 1,3benzazaphospholides 1L1, ambident benzofused azaphosphacyclopentadienides, are presented. The unusual properties of phospholyl-l,3,2-diazaphospholes inspired us to study the coupling
- Aluri, Bhaskar R.,Burck, Sebastian,Gudat, Dietrich,Niemeyer, Mark,Holloczki, Oldamur,Nyulaszi, Laszlo,Jones, Peter G.,Heinicke, Joachim
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experimental part
p. 12263 - 12272
(2010/06/11)
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- Reduction of tertiary phosphine oxides with DIBAL-H
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(Chemical Equation Presented) The reduction of tertiary phosphine oxides (TPOs) and sulfides with diisobutylaluminum hydride (DIBAL-II) has been studied in detail. An extensive solvent screen has revealed that hindered aliphatic ethers, such as MTBE, are optimum for this reaction at ambient temperature. Many TPOs undergo considerable reduction at ambient temperature and then stall due to inhibition. 31P and 13C NMR studies using isotopically labeled substrates as well as competition studies have revealed that the source of this inhibition is tetraisobutyldialuminoxane (TIBAO), which builds up as the reaction proceeds. TIBAO selectively coordinates the TPO starting material, preventing further reduction. Several strategies have been found to circumvent this inhibition and obtain full conversion with this extremely inexpensive reducing agent for the first time. Practical reduction protocols for these critical targets have been developed.
- Busacca, Carl A.,Raju, Ravinder,Grinberg, Nelu,Haddad, Nizar,James-Jones, Paul,Lee, Heewon,Lorenz, Jon C.,Saha, Anjan,Senanayake, Chris H.
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p. 1524 - 1531
(2008/04/12)
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- SHOP-type nickel complexes with alkyl substituents on phosphorus, synthesis and catalytic ethylene oligomerization
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The β-keto phosphorus ylides (n-Bu)3P=CHC(O)Ph 6, (t-Bu)2PhP=CHC(O)Ph 7, (t-Bu)Ph2P=CHC(O)Ph 8, (n-Bu) 2PhP=CHC(O)Ph 9, (n-Bu)Ph2P=CHC(O)Ph 10, Me 2PhP=CHC(O)Ph 11 and Ph3P=CHC(O)(o-OMe-C6H 4) 12 have been synthesized in 80-96% yields. The Ni(ii) complexes [N=iPh{Ph2PCHC(O=)(o-OMeC6H4)}(PPh 3)] 13, [N=iPh{Ph(t-Bu)PCHC(O=)Ph}(PPh3)] 15, [N=iPh{(n-Bu)2PCHC(O=)Ph}(PPh3)] 16 and [N=iPh{Ph(n-Bu)PCHC(O=)Ph}(PPh3)] 17 have been prepared by reaction of equimolar amounts of [Ni(COD)2] and PPh3 with the β-keto phosphorus ylides 12 or 8-10, respectively, and characterized by 1H and 31P{1H} NMR spectroscopy. NMR studies and the crystal structure determination of 13 indicated an interaction between the hydrogen atom of the C-H group α to phosphorus and the ether function. The complexes [N=iPh{Ph2PCHC(O=)Ph}(Py)] 18, [N=iPh{Ph(t-Bu)PCHC(O=) Ph}(Py)] 19, [N=iPh{(n-Bu)2PCHC(O=)Ph}(Py)] 20, [N=iPh{Ph(n-Bu) PCHC(O=)Ph}(Py)] 21 and [N=iPh{Me2PCHC(O=)Ph}(Py)] 22 have been isolated from the reactions of [Ni(COD)2] and an excess of pyridine with the β-keto phosphorus ylides Ph3PCH=C(O)Ph 3 or 8-11, respectively, and characterized by 1H and 31P{ 1H} NMR spectroscopy. Ligands 3, 8, 10 and 12 have been used to prepare in situ oligomerization catalysts by reaction with one equiv. of [Ni(COD)2] and PPh3 under an ethylene pressure of 30 or 60 bar. The catalyst prepared in situ from 12, [Ni(COD)2] and PPh 3 was the most active of the series with a TON of 12 700 mol C 2H4 (mol Ni)-1 under 30 bar ethylene. When the β-keto phosphorus ylide 8 was reacted in situ with three equiv. of [Ni(COD)2] and one equiv. of PPh3 under 30 bar of ethylene, ethylene polymerization was observed with a TON of 5500 mol C 2H4 (mol Ni)-1. The Royal Society of Chemistry.
- Kermagoret, Anthony,Braunstein, Pierre
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p. 822 - 831
(2008/09/20)
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- Homolytic substitution at phosphorus for the synthesis of alkyl and aryl phosphanes
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(Chemical Equation Presented) A transition-metal-free radical phosphonation using Me3SnPPh2 and the less toxic Me 3SiPPh2 is reported. These readily available reagents react highly efficiently with primary and secondary alkyl radicals. Moreover, aryl radicals and tertiary alkyl radicals are phosphonated with Me 3SnPPh2 (see scheme; R = aryl, alkyl, vinyl; X = 1, Br, OC(S)imidazolyl). DFT calculations provide insights into the mechanism of the reaction.
- Vaillard, Santiago E.,Mueck-Lichtenfeld, Christian,Grimme, Stefan,Studer, Armido
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p. 6533 - 6536
(2008/09/17)
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- Expanding the range of "Daniphos"-type P∩P- and P∩N-ligands: Synthesis and structural characterisation of new [(η6-arene)Cr(CO)3] complexes
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New P∩P- and P∩N-ligands have been synthesised whose core structure is an [(η6-arene)Cr(CO)3] unit. These new ligands, which extend the range of "Daniphos" ligands, are endowed with central and planar chirality and have been prepared through a stereoselective synthetic strategy from optically pure benzylamines bearing a second substituent on the arene other than the benzyldimethylamino group. Because the two faces of unsymmetrically 1,2- and 1,3-disubstituted benzylamine are diastereotopic, which means that diastereomeric complexes arise upon coordination of the Cr(CO) 3 fragment to either of these two faces, the synthetic plan has been adjusted by exploiting the trimethylsilyl group as a temporary steric modulator in order to access both complexes with high diastereoselectivity. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Alberico, Elisabetta,Braun, Wolfgang,Calmuschi-Cula, Beatrice,Englert, Ulli,Salzer, Albrecht,Totev, Daniel
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p. 4923 - 4945
(2008/09/17)
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- Radical phosphination of organic halides and alkyl imidazole-1- carbothioates
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Taking advantage of a radical-based methodology, mild and chemoselective phosphination reactions of organic halide and alkyl imidazole-1-carbothioates have been developed. The mild reaction conditions allow labile functional groups to survive during the reaction. Copyright
- Sato, Akinori,Yorimitsu, Hideki,Oshima, Koichiro
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p. 4240 - 4241
(2007/10/03)
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- Tri(tert-butyl)plumbyl-phosphanes, synthesis and multinuclear magnetic resonance
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The reaction of tri(tert-butyl)plumbyl-lithium (1) with various phosphorus chlorides was studied. With diphenyl-and amino(phenyl)phosphorus chlorides the formation of hexa(tertbutyl)diplumbane (2) and tetraphenyldiphosphane (3) or the respective 1,2-bis(amino)-1,2-diphenyl-diphosphanes [e.g. 5: amino = PhCH2(tBu)N] was dominant. The presence of at least one tert-butyl group at the phosphorus atom gave access to tri(tert-butyl)plumbyl-di(tert-butyl)phosphane (4) and to tri(tert-butyl)plumbyl-amino(tert-butyl)phosphanes [amino = tBu(H)N (6), Me(Ph)N (7), PhCH2(Me)N (8), PhCH2(tBu)N (9)] via the reaction of 1 with the corresponding phosphorus chlorides. Side products were again 2 and the corresponding diphosphanes, unidentified compounds, and in two cases, bis(phosphanyl)-di(tert-butyl)plumbanes [phosphanyl = tBu(H)N(tBu)P (10), Me(Ph)N(tBu)P (11)]. Trimethylplumbyl-benzyl(methyl)-amino(tert-butyl)phosphane (12) was prepared for comparison. All compounds were characterized by their 1H, 13C, 15N (9), 31P and 207Pb NMR data. The coupling constants 1J(207Pb,31P) are large and negative, whereas the coupling constants 1J(207Pb, 13C) are small and can be of either sign. The coupling constants 2J(31P-N-13C) of 6 - 12 indicate a preferred conformation of the substituents at phosphorus and nitrogen.
- Herberhold, Max,K?hler, Christian,Tr?bs, Volker,Wrackmeyer, Bernd
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p. 939 - 945
(2007/10/03)
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- [Cp2ZrHCl](n) A useful reducing agent in phosphorus chemistry
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Selective reductions of P=O, P=S, >C=C2ZrHCl](n) are described, as well as halogen-hydride exchanges.
- Zablocka, Maria,Delest, Bruno,Igau, Alain,Skowronska, Aleksandra,Majoral, Jean-Pierre
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p. 5997 - 6000
(2007/10/03)
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- SRN1 Reactions of t-Butyl Chlorides
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t-Butyl chloride and 2-chloro-2-methyl-1-phenylpropane reacted with Ph2P- ions under irradiation to give reduction and substitution products and 6-chloro-6-methylhept-1-ene (used as a radical probe) reacted to give the cyclized substitution product.The bromides gave only elimination products.
- Santiago, Ana N.,Rossi, Roberto A.
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p. 206 - 208
(2007/10/02)
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- ELECTRON-TRANSFER PROCESSES. PART 40. REACTION OF ALKYL RADICALS WITH DIPHENYLPHOSPHIDE ANION
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The anion Ph2P- (K+, 18-crown-6) reacts with t-BuHgCl in HMPA to form Ph2PCMe3 by a free radical chain mechanism.In Me2SO, PhP(O)CMe3 is produced.Reaction of Ph2P- with PhCOCH2HgCl yields the oxidative dimerization product isolable from HMPA but readily converted to Ph2P(O)P(O)Ph2 in Me2SO.
- Russell, Glen A.,Khanna, Rajive K.
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p. 271 - 274
(2007/10/02)
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- Process for the preparation of bulky alkyldiarylphosphines and unsymmetrical aryldialkyl phosphines
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A process for the selective production of bulky alkyldiarylphosphines and unsymmetrical dialkylarylphosphines comprising reacting a first Grignard reagent having a bulky alkyl group with an aryldichlorophosphine and thereafter and without isolating the resulting bulky alkylarylchlorophosphine intermediate, reacting said intermediate with a second Grignard reagent having a different, less bullky alkyl group or an aryl group to provide the product phosphine.
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- Free Radical Reactions of 1,1-Diarylethylenes with t-Butylmercury Chloride
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The photostimulated reactions of Bu(t)HgCl with 1,1-diarylethylenes yield different products for the aryl groups C6H5, p-O2NC6H4, or p-MeOC6H4 reflecting the donor or acceptor properties of Bu(t)CB2C(*)(Ar)2.
- Russell, Glen A.,Khanna, Rajive K.,Guo, Deliang
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p. 632 - 634
(2007/10/02)
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- Preparation and Characterization of Trichlorostannylplatinum Hydride Complexes Containing Sterically Bulky Phosphine Ligands
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Trichlorostannylplatinum(II) hydride complexes containing sterically bulky phosphine ligands, trans-(R3P)2PtH(SnCl3)(1) R3P=t-BuPh2P, Cy3P, t-Bu2MeP) have been prepared by the reaction of hydrated tin(II) dichloride with respective chloro-platinum hydride complexes.A trans-geometry has been assigned for the complexes (1) on the basis of 1H and 31P NMR spectral studies.An unusually large magnitude of two-bond tin-hydrogen coupling (JSn-H ca.1598-1682 Hz) has been observed in the PMR spectra of these complexes.From the reaction of tin (II) dichloride with trans-(t-Bu3P)2PtH(Cl), surprisingly, a complex corresponding to (t-Bu3P)PtCl(SnCl3) (3) has been obtained.In solutions, one of the tri-t-butylphosphines of 3, undergoes intramolecular metalation generating a new, probably a platinum (IV) complex, .
- Goel, Anil B.,Goel, Sarla
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p. 980 - 982
(2007/10/02)
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- SYNTHESIS AND INFRARED STUDY OF (C6H5)nPX3-nCr(CO)5 (X=Cl, Br, I, H; n=0-3) AND (C6H5)2PRCr(CO)5 (R=METHYL, ETHYL, i-PROPYL, t-BUTYL) COMPOUNDS
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A method for the preparation of (C6H5)nPX3-nCr(CO)5 complexes in the crystalline state is described.The carbon-oxygen stretching vibration, νCO(A1 eq.), of the complexes with X=Cl, Br, I is mainly determined by the inductive effect of the (C6H5)nPX3-n group.For X=H, the νCO band is defined by the concomitant influence of the ?, ? and steric effects.
- Vincent, E.,Verdonck, L.,Kelen, G. P. van der
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