- The Use of Catalytic Amounts of CuCl and Other Improvements in the Benzyne Route to Biphenyl-Based Phosphine Ligands
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Biphenyl-based phosphine ligands can be prepared on a significantly larger scale than previously possible as a result of the following discoveries and improvements to the original experimental procedure: the finding that CuCl catalyzes the coupling of hindered dialkylchlorophosphines with Grignard reagents; the development of conditions that permit ClPCy2 to be prepared and utilized in situ; the development of a more reliable large-scale preparation of 2-dimethylaminophenylmagnesium halide.
- Kaye, Steven,Fox, Joseph M.,Hicks, Frederick A.,Buchwald, Stephen L.
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- DIALKYL(2-ALKOXY-6-AMINOPHENYL)PHOSPHINE, THE PREPARATION METHOD AND USE THEREOF
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The present invention relates to the compound of dialkyl(2-alkoxy-6-aminophenyl)phosphine and the preparation method thereof and the application in the palladium catalyzed coupling reactions of aryl chloride and ketone. The dialkyl(2-alkoxy-6-aminophenyl)phosphine of the present invention could coordinate with the palladium catalyst to highly selectively activate the inert carbon-chlorine bond, and to catalyze direct arylation reaction in the α-position of ketones to produce corresponding coupling compounds. The preparation method of the present invention is a simple one-step method which produces the air-stable dialkyl(2-alkoxy-6-aminophenyl)phosphine. Compared with the synthetic routes of ligands to be used in the activation of carbon-chlorine bonds in the prior arts, the preparation method of the present invention has the advantages of short route and easy operation.
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- Zheda-phos for general α-monoarylation of acetone with aryl chlorides
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A new, readily available, and air-stable monophosphine ligand, i.e., Zheda-Phos, has been developed for the general and highly effective palladium-catalyzed monoarylation of acetone with aryl chlorides. The reaction rate is of first-order dependence with the aryl chloride. Copyright
- Li, Pengbin,Lue, Bo,Fu, Chunling,Ma, Shengming
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supporting information
p. 1255 - 1259
(2013/06/27)
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- STRUCTURE AND METHOD FOR SYNTHESIZING AND USING DIALKYL(2,4,6- OR 2,6-ALKOXYPHENYL)PHOSPHINE AND ITS TETRAFLUOROBORATE
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The current invention relates to the structure, synthesis of dialkyl(2,4,6- or 2,6-alkoxyphenyl)phosphine or its tetrafluoroborate, as well as its applications in the palladium catalyzed carbon-chlorine bond activation for Suzuki coupling reactions and carbon-nitrogen bond formation reactions. The dialkyl(2,4,6- or 2,6-alkoxyphenyl)phosphine or its tetrafluoroborate could coordinate with the palladium catalyst to activate the inert carbon-chlorine bond highly selectively and catalyze Suzuki coupling reaction with arylboronic acid or carbon-nitrogen bond formation reaction with organic amines. The current invention uses only one step to synthesize dialkyl(2,4,6- or 2,6-alkoxyphenyl)phosphine and its tetrafluoroborate is stable in the air. Compared with known synthetic routes of ligands used in activating carbon-chlorine bonds, the method of current invention is short, easy to operate. Moreover, with this type of ligands, the Suzuki coupling products of optically active chlorolactones and arylboronic acids would maintain their configuration and optical purity.
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- 2,6-diisopropoxyphenyl(dicyclohexyl)phosphine: A new ligand for palladium-catalyzed amination reactions of aryl chlorides with potassium hydroxide as the base
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A new, readily available monophosphine tetrafluoroborate salt [L2·HBF4] was developed for the palladium-catalyzed amination reaction of aryl chlorides in moderate to high yields with the cheap and easily available potassium hydroxide as the base. The reaction enjoys a wide scope, lower reaction temperatures, shorter reaction times, high yields, and low catalyst loading when compared to some of same amination reactions reported in the literature. Based on a kinetic study, 31P NMR measurements, and DFT calculations, a mechanism involving a 1:1 Pd/L species is proposed.
- Lue, Bo,Li, Pengbin,Fu, Chunling,Xue, Liqin,Lin, Zhenyang,Ma, Shengming
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experimental part
p. 100 - 112
(2011/04/12)
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- Application of a readily available and air stable monophosphine HBF4 salt for the Suzuki coupling reaction of aryl or 1-alkenyl chlorides
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In this Letter, a readily available monophosphine HBF4 salt was applied for the Suzuki coupling reactions of organoboronic acids to afford the cross-coupling products in high to excellent yields. Both aryl or 1-alkenyl boronic acids and chlorides may be used. It is also suitable for sterically hindered cases.
- Lü, Bo,Fu, Chunling,Ma, Shengming
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supporting information; experimental part
p. 1284 - 1286
(2010/04/27)
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- METHOD FOR PREPARING HALOGENATED ORGANOPHOSPHINES
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The present application relates to a process for preparing a halogenated organophosphine, comprising reacting a primary or secondary organophosphine with a halogenating agent selected from (A) a compound of formula (I) : (HaI)3C-C(O)-X (I) wherein X is selected from alkyl, aryl, aralkyl, alkaryl, cycloalkyl, NR1R2, C(HaI)3, OR3, -0-C(O)-R3', or -Y-Z-Y-C(O)- C(HaI)3; R1 and R2 are each independently selected from hydrogen, alkyl, aryl, aralkyl, alkaryl, or cycloalkyl; R3 is selected from H, alkyl, aryl, aralkyl, alkaryl, cycloalkyl, or triorganosilyl; R3' is selected from C(HaI)3, alkyl, aryl, aralkyl, alkaryl, cycloalkyl; Y is independently selected from 0 or NH; Z is independently selected from alkylene, arylene, aralkylene, alkarylene, or cycloakylene; and Hal is selected from Cl or Br; or (B) a derivative of a polyol, polyamine or polyaminoalcohol comprising two or more hydroxyl and/or amino groups, in which a hydrogen atom in each of the hydroxyl and/or amino groups is replaced with a group -C(O)-C(HaI)3, wherein Hal is selected from Cl or Br.
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Page/Page column 16
(2009/12/28)
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- Industrial-scale palladium-catalyzed coupling of aryl halides and amines - A personal account
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The palladium-catalyzed coupling of amines and aryl halides or aryl alcohol derivatives has matured from an exotic small-scale transformation into a very general, efficient and robust reaction during the last ten years. This article reports several applications of this method from an industrial vantage point, including ligand synthesis, synthesis of arylpiperazines, arylhydrazines and diarylamines. Much emphasis in placed on issues of scale-up and safety to underline the potential of C-N couplings as solutions for industrial-scale synthetic problems.
- Buchwald, Stephen L.,Mauger, Christelle,Mignani, Gerard,Scholz, Ulrich
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- Sterically crowded diphosphinomethane ligands: Molecular structures, UV-photoelectron spectroscopy and a convenient general synthesis of tBu2PCH2PtBu2 and related species
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A series of highly crowded symmetric and unsymmetric diphosphinomethanes R2PCH2PR′2, important ligands in transition metal chemistry and catalysis, namely tBu2PCH2ptBu2 (dtbpm, 11), Cy2PCH2PCy2 (dcpm, 2), tBu2PCH2PCy2 (ctbpm, 3), tBu2PCH2PiPr2 (iptbpm, 4) and tBu2PCH2PPh2 (ptbpm, 5), has been prepared in high yields, using a general and convenient route, which is described in detail for 1. Other than 4, which is a colourless liquid, these compounds are crystalline solids at room temperature. Their molecular structures have been determined by single crystal X-ray diffraction, along with that of the higher homologue of 1, tBu2CH2CH2tBu 2 (dtbpe, 6). The solid-state structures of the dioxide of 1, tBu2P(O)CH2P(O)tBu2 (7), and of two phosphonium cations derived from 1, protonated [tBu2P(H)CH2PtBu2] + (8+) and the chlorophosphonium ion [tBu2P(Cl)CH2PtBu2] + (9+), are also described and show a distinct structural influence of the tetracoordinate P centres. The gas phase UV-photoelectron spectra of the diphosphines 1-6 have been measured. Their first two ionisation potentials are found to be nearly degenerate and all are in the low energy range from 7.5 to 7.8 eV. Comparison with related mono- and bidentate phosphines demonstrates that 1-6 are excellent σ-donors towards metals, in accord with their known coordination chemistry. Molecular geometries and electronic structures of the diphosphine systems have been studied by quantum chemical calculations and are compared to experiment. Unlike standard semiempirical methods (AM1, PM3, MNDO), which give rather poor minimum structures and seem inadequate for such sterically crowded systems, ab initio calculations (RHF/6-31G**) predict molecular geometries with reasonable accuracy and reflect the observed trends in experimental ionisation potentials.
- Eisentraeger, Frank,Goethlich, Alexander,Gruber, Irene,Heiss, Helmut,Kiener, Christoph A.,Krueger, Carl,Notheis, J. Ulrich,Rominger, Frank,Scherhag, Gunter,Schultz, Madeleine,Straub, Bernd F.,Volland, Martin A. O.,Hofmann, Peter
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p. 540 - 550
(2007/10/03)
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- Asymmetric hydrogenation reactions mediated by a new class of bicyclic bisphosphinites
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The bicyclic alcohol (-)-4 was prepared from (-)-bicyclo[3.2.0]hept-2- en-6-one (-)-1 in 50% yield. The diol (-)-4 was coupled to selected chlorophosphines 6-12 to produce a series of bisphosphinites 13-19 in 89-95% yield. From these bisphosphinites were prepared the rhodium complexes 20-26 which were characterised by 31P NMR and used in situ for the asymmetric hydrogenation of α-enamides 27-29. Complexes 21, 23-25 proved to be the superior catalysts for the production of (R)-N-acetylphenylalanine (91, 84, 90 and 87.5% ee) from 27 and (S)-N-acetylalanine methyl ester (70, 72, 68 and 71% ee) from 28.
- Derrien, Nadine,Dousson, Cyril B.,Roberts, Stanley M.,Berens, Ulrich,Burk, Mark J.,Ohff, Manuela
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p. 3341 - 3352
(2007/10/03)
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- Mono-, Di- and Trichloroacetylditolyl- and -dicyclohexylphosphanes
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Reaction of the acid chlorides X1X2X3CC(O)Cl (1ax-bz) with the silylphosphanes Me3SiPR2 (2a, b) results in the formation of the mono-, di- and trichloroacetylditolyl- and -dicyclohexylphosphanes X1X2X3CC(O)PR2 (3ax-bz). 3bx-bz are thermally unstable and decompose at 20 deg C to give ClP(c-C6H11)2.Stereochemical effects cause the 31P signal in the spectra of the series 3ax-az and 3bx-bz to shift to higher fields with increasing content of chlorine in the acetyl group. - Keywords: Chloroacetyldiorganylphosphanes, NMR Spectra
- Lindner, Ekkehard,Merkle, Ralf Dieter
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p. 1580 - 1582
(2007/10/02)
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