Search results

Search for "phosphines" in Full Text gives 106 result(s) in Beilstein Journal of Organic Chemistry.

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

  • Maurizio Selva,
  • Alvise Perosa,
  • Sandro Guidi and
  • Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

Graphical Abstract
  • protonation or quaternization of neutral precursors (imidazoles, amines, phosphines, pyridine or sulfides) with Brønsted acids or haloalkanes/dialkylsulfates, respectively. In the next step, a variety of ionic liquids are obtainable by anion exchange, either through direct treatments with Lewis acids or by
  • diols can be carried out in the presence of basic (e.g., tertiary phosphines and amines, alkali metal hydroxides, alkoxides, halides, carbonates, alkali metal exchanged faujasites and hydrotalcites) or acidic catalysts or co-catalysts, and under thermal (non-catalytic) conditions. All applicable
  • phosphines and amines by dimethyl carbonate (Q = N, P). Bottom: anion metathesis of methyl carbonate onium salts. Synthesis of the acid polymeric IL. EGDMA: ethylene glycol dimethacrylate. The transesterification of sec-butyl acetate with MeOH catalyzed by some acidic imidazolium ILs. Top: phosgenation of
PDF
Album
Review
Published 26 Aug 2016

Experimental and theoretical investigations on the high-electron donor character of pyrido-annelated N-heterocyclic carbenes

  • Michael Nonnenmacher,
  • Dominik M. Buck and
  • Doris Kunz

Beilstein J. Org. Chem. 2016, 12, 1884–1896, doi:10.3762/bjoc.12.178

Graphical Abstract
  • of the CO ligand by phosphines in [M(CO)2Cl(NHC)] complexes (M = Rh, Ir) or even by DMSO [60][61][62] occurs at the trans-CO ligand. In some cases, loss of CO upon formation of dimers can be observed for rhodium NHC complexes [63][64][65]. Ligand exchange in square planar Rh(I) carbonyl complexes was
PDF
Album
Supp Info
Full Research Paper
Published 23 Aug 2016

A T-shape diphosphinoborane palladium(0) complex

  • Patrick Steinhoff and
  • Michael E. Tauchert

Beilstein J. Org. Chem. 2016, 12, 1573–1576, doi:10.3762/bjoc.12.152

Graphical Abstract
  • complexes only few examples featuring a η1-type Pd→B interaction have been reported [6][7]. However, these complexes require phosphines or pyridines as a stabilizing co-ligand, which can act as an inhibitor in catalytic transformations [7]. Similarly, monometallic 14 VE palladium complexes featuring a
PDF
Album
Supp Info
Letter
Published 22 Jul 2016

Ring-whizzing in polyene-PtL2 complexes revisited

  • Oluwakemi A. Oloba-Whenu,
  • Thomas A. Albright and
  • Chirine Soubra-Ghaoui

Beilstein J. Org. Chem. 2016, 12, 1410–1420, doi:10.3762/bjoc.12.135

Graphical Abstract
  • haptotropic rearrangement of 48 to 53. Notice that passage through the η2 intermediate causes the phosphines to become equivalent. Benn and co-workers [74] in fact observe phosphine equivalence with a barrier of approximately 13 kcal/mol for the naphthalene–Ni(PR3)2 compounds. Our calculations put 54 to be
  • found on the potential energy surface of C8F8–Pt(dpe). For clarity the groups around the phosphines have been removed. The relative energies for this compound, as well as COT–Pt(dpe) are given below each structure. The two important bonding interactions for transition state 31 are drawn in 33 and 34
PDF
Album
Supp Info
Full Research Paper
Published 07 Jul 2016

Conjugate addition–enantioselective protonation reactions

  • James P. Phelan and
  • Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

Graphical Abstract
  • reported the hydrophosphination of methacrylonitirle 174 catalyzed by nickel(II)/(R,R)-Pigiphos complex 171 (Scheme 41) [71]. The reaction proceeded in good yield for alkyl phosphines (71–97% yield) and with higher enantioselectivity for the more sterically encumbered alkyl groups (R = Ad, 97:3 er). Togni
PDF
Album
Review
Published 15 Jun 2016

NeoPHOX – a structurally tunable ligand system for asymmetric catalysis

  • Jaroslav Padevět,
  • Marcus G. Schrems,
  • Robin Scheil and
  • Andreas Pfaltz

Beilstein J. Org. Chem. 2016, 12, 1185–1195, doi:10.3762/bjoc.12.114

Graphical Abstract
  • from the secondary phosphines by deprotonation with KH in refluxing THF. The NeoPHOX ligands, which were obtained by this route in high overall yield, proved to be air and moisture stable and could be obtained in analytically pure form by simple filtration through silica gel [19]. Complexation with [Ir
PDF
Album
Supp Info
Full Research Paper
Published 13 Jun 2016

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

  • Barry M. Trost,
  • Michael C. Ryan and
  • Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

Graphical Abstract
  • , entry 5). In general, untethered, exogenous sulfoxides are poorer ligands to ruthenium than phosphines or phosphites. As the reaction temperature is lowered to 40 °C, however, one begins to see a significant decrease in reaction rate and conversion (Table 1, entry 6). The enantioselectivity of the
  • phosphines, biaryl sulfoxides, or monoaryl monoalkyl sulfoxides. After 1.5 hours, (S)-methyl p-tolyl sulfoxide also showed no conversion (Table 4, entry 5). Since subtle changes in the structure of the enyne substrate could have a significant impact on enantioselectivity, variations of the substituent on
PDF
Album
Supp Info
Full Research Paper
Published 07 Jun 2016

Enantioselective [3 + 2] annulation of α-substituted allenoates with β,γ-unsaturated N-sulfonylimines catalyzed by a bifunctional dipeptide phosphine

  • Huanzhen Ni,
  • Weijun Yao and
  • Yixin Lu

Beilstein J. Org. Chem. 2016, 12, 343–348, doi:10.3762/bjoc.12.37

Graphical Abstract
  • -sulfonylimines proceeded in an unexpected [3 + 2] annulation mode to afford a cyclopentene ring with an all-carbon quaternary center (Scheme 1) [48]. In recent years our group has developed a family of amino acid-derived bifunctional phosphines and has intensively investigated related asymmetric transformations
  • allenoate 1a and β,γ-unsaturated N-sulfonylimine 2a as a model reaction and evaluated a number of amino acid based bifunctional phosphines as catalyst. As shown in Table 1, simple L-valine-derived phosphines 3a–c were found to be effective in promoting the reaction, and products were obtained in moderate to
  • phosphine catalyst furnishes the final [3 + 2] annulation product 5. Conclusion In conclusion, we have described the first enantioselective [3 + 2] cycloaddition of α-substituted allenoates with β,γ-unsaturated N-sulfonylimines, catalyzed by amino acid-derived bifunctional phosphines. The [3 + 2] annulation
PDF
Album
Supp Info
Full Research Paper
Published 24 Feb 2016

Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

  • Sophie Letort,
  • Sébastien Balieu,
  • William Erb,
  • Géraldine Gouhier and
  • François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

Graphical Abstract
  • commercial impacts during the last decades, phosphates, phosphonates, phosphinates, or phosphines being prominent in several fields. As an example, drugs bearing an organophosphorus moiety hold a significant place in chemotherapy for the treatment of various diseases. Nevertheless, the high polarity of these
PDF
Album
Review
Published 05 Feb 2016

Pyridylidene ligand facilitates gold-catalyzed oxidative C–H arylation of heterocycles

  • Kazuhiro Hata,
  • Hideto Ito,
  • Yasutomo Segawa and
  • Kenichiro Itami

Beilstein J. Org. Chem. 2015, 11, 2737–2746, doi:10.3762/bjoc.11.295

Graphical Abstract
  • -catalyzed reactions, phosphines, N-heterocyclic carbenes, pyridines and salen ligands have been applied as ligands for controlling the stability of catalysts, and chemo-, regio- and enantioselectivities of the reactions [31][32][33][34][35][36]. Recent advances in the gold-catalyzed reactions are
PDF
Album
Supp Info
Full Research Paper
Published 28 Dec 2015

Aerobic addition of secondary phosphine oxides to vinyl sulfides: a shortcut to 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl)phosphine oxides

  • Svetlana F. Malysheva,
  • Alexander V. Artem’ev,
  • Nina K. Gusarova,
  • Nataliya A. Belogorlova,
  • Alexander I. Albanov,
  • C. W. Liu and
  • Boris A. Trofimov

Beilstein J. Org. Chem. 2015, 11, 1985–1990, doi:10.3762/bjoc.11.214

Graphical Abstract
  • )phosphine oxides in 70–93% yields. Keywords: addition; green method; phosphine oxides; regioselectivity; vinyl sulfides; Findings Tertiary phosphines and phosphine chalcogenides are important organophosphorus compounds that are widely used in industry, organic synthesis, polymer science, medicinal and
  • approaches to construct new C–P bonds, that provide straightforward access to tertiary phosphines and their chalcogenides [8][9][10][11][12]. Conventionally, the activation of the P–H bonds in this reaction is achieved by using radical initiators [13][14][15], Brønsted/Lewis acids [16][17] and bases [18][19
  • ][20] as well as transition metal catalysts [21][22][23]. Also, examples of the microwave-assisted [24][25] and photoinduced [26] addition are described. Recently, on example of secondary phosphines [27] as well as secondary phosphine sulfides [28] and selenides [29], it has been disclosed that the
PDF
Album
Supp Info
Letter
Published 23 Oct 2015

Ruthenium indenylidene “1st generation” olefin metathesis catalysts containing triisopropyl phosphite

  • Stefano Guidone,
  • Fady Nahra,
  • Alexandra M. Z. Slawin and
  • Catherine S. J. Cazin

Beilstein J. Org. Chem. 2015, 11, 1520–1527, doi:10.3762/bjoc.11.166

Graphical Abstract
  • general, the commonly used Ru(II)-based pre-catalysts have five ligands in the metal coordination sphere and adopt a distorted square pyramidal geometry (Figure 1). The basic components of this structure include two L-type ligands mutually trans (e.g., phosphines and N-heterocyclic carbene) and two
  • phosphines [14][15][16][17][18][19][20][21][22][23]. The most common phosphine, so called “throw-away ligand”, is tricyclohexyl phosphine [10][11][12][13][14][15][16][17][18][19][20][21][22][23]. In other words, such phosphorus donor ligands dissociate from the metal center to afford the 14e− active species
  • [10][11][12][13][24]. In order to reduce the cost of the Ru-based pre-catalyst, our group has investigated the use of phosphites as an economical alternative to phosphines. The reaction of triisopropyl phosphite with the pyridine-containing indenylidene complex [RuCl2(Ind)(SIMes)(py)] (SIMes = N,N
PDF
Album
Supp Info
Full Research Paper
Published 01 Sep 2015

Synthesis of γ-hydroxypropyl P-chirogenic (±)-phosphorus oxide derivatives by regioselective ring-opening of oxaphospholane 2-oxide precursors

  • Iris Binyamin,
  • Shoval Meidan-Shani and
  • Nissan Ashkenazi

Beilstein J. Org. Chem. 2015, 11, 1332–1339, doi:10.3762/bjoc.11.143

Graphical Abstract
  • unique interest from a synthetic point of view due to their ability to create new phosphines [48] or to be involved in various reactions (e.g., [2 + 3] cycloaddition) [49][50]. Moreover, propargyl compounds are known to undergo base catalyzed 1,3-prototropic rearrangments to the corresponding allenes [51
  • fact that the γ-hydroxypropyl substituent, which results directly from the ring opening of the phospholane, could provide a second ligation site upon complexation of the corresponding phosphines to a transition metal catalyst. These P,O bidentate ligands are quite useful in organometallic compounds
PDF
Album
Supp Info
Full Research Paper
Published 30 Jul 2015

Highly selective palladium–benzothiazole carbene-catalyzed allylation of active methylene compounds under neutral conditions

  • Antonio Monopoli,
  • Pietro Cotugno,
  • Carlo G. Zambonin,
  • Francesco Ciminale and
  • Angelo Nacci

Beilstein J. Org. Chem. 2015, 11, 994–999, doi:10.3762/bjoc.11.111

Graphical Abstract
  • overreactions giving the diallylated compounds [23][24], the need for catalysts that are tedious to prepare [18][19], and the use of toxic or expensive ligands such as phosphanes or phosphites [3][25]. Therefore, the careful selection of a suitable ligand capable for replacing phosphines and improving palladium
PDF
Album
Supp Info
Letter
Published 10 Jun 2015

Hydrogenation of unactivated enamines to tertiary amines: rhodium complexes of fluorinated phosphines give marked improvements in catalytic activity

  • Sergey Tin,
  • Tamara Fanjul and
  • Matthew L. Clarke

Beilstein J. Org. Chem. 2015, 11, 622–627, doi:10.3762/bjoc.11.70

Graphical Abstract
  • Abstract In the hydrogenation of sluggish unactivated enamine substrates, Rh complexes of electron-deficient phosphines are demonstrated to be far more reactive catalysts than those derived from triphenylphosphine. These operate at low catalyst loadings (down to 0.01 mol %) and are able to reduce
  • faster using Rh complexes of electron-withdrawing phosphines. In this paper, we report how a range of enamines can be successfully hydrogenated in high yield using low levels of rhodium, including some very deactivated enamines that do not hydrogenate using conventional catalysts. Results and Discussion
  • , particularly commercially available 7, 8 [25] or also commercial product 9, show faster rates of hydrogenation of 1e. It can be envisaged that other less electron-donating phosphines could also be used to good effect, providing they are stable under the reaction conditions. It is possible that stability is an
PDF
Album
Supp Info
Full Research Paper
Published 05 May 2015

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

  • William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

Graphical Abstract
  • several groups suggests that the inversion barrier is decreased to below 20 kcal/mol [28][29][30]. In order to extend the comparison from phosphines to phosphites, we recently showed that dinucleoside phosphite triesters, like phosphines, epimerize slowly – in this case at 150 °C with an inversion barrier
  • of 33 kcal/mol [31]. Since the replacement of an alkyl or aryl group in phosphines by an acyl group lowered the epimerization barrier by >13 kcal/mol, it seemed reasonable to propose the same could happen by a similar replacement of an alkoxy group in phosphite triesters. Although the required
  • differences in rates of diastereomer decomposition. Calculation of acylphosphonite inversion barrier. As described in the Introduction, inversion barriers for phosphines, acylphosphines, and phosphites are known. These were calculated first for validation of the method. The structures of chiral phosphine 18
PDF
Album
Supp Info
Full Research Paper
Published 30 Jan 2015

Enhancing the reactivity of 1,2-diphospholes in cycloaddition reactions

  • Almaz Zagidullin,
  • Vasili Miluykov,
  • Elena Oshchepkova,
  • Artem Tufatullin,
  • Olga Kataeva and
  • Oleg Sinyashin

Beilstein J. Org. Chem. 2015, 11, 169–173, doi:10.3762/bjoc.11.17

Graphical Abstract
  • : cycloaddition; phospholes; phosphorus heterocycles; polycyclic phosphines; retro-Diels–Alder reaction; Introduction Phospholes are weakly aromatic heterocycles and demonstrate rather different properties from those of their S, N and O counterparts [1][2]. Due to low their aromaticity, phospholes are of
  • significant interest for the preparation of highly effective catalysts, materials for light-emitting diodes and nonlinear optics [3][4]. In contrast to furans, thiophenes and pyrroles, phospholes display cycloaddition and complexation reactions and can be used as starting materials for caged phosphines
  • cycloaddition reactions, this work presents the opportunity for new polycyclic phosphines. ORTEP view of 2,3,4,4a,5,6-hexa(p-fluorophenyl)-1-ethyl-1,7,7a-triphospha-4,7-(ethylphosphinidene)indene (2e). Hydrogen atoms are omitted for clarity. Selected bond lengths [Å] and angles [°]: P1–C1 1.850(5); P1–С4 1.923
PDF
Album
Supp Info
Full Research Paper
Published 27 Jan 2015

Phosphinocyclodextrins as confining units for catalytic metal centres. Applications to carbon–carbon bond forming reactions

  • Matthieu Jouffroy,
  • Rafael Gramage-Doria,
  • David Sémeril,
  • Dominique Armspach,
  • Dominique Matt,
  • Werner Oberhauser and
  • Loïc Toupet

Beilstein J. Org. Chem. 2014, 10, 2388–2405, doi:10.3762/bjoc.10.249

Graphical Abstract
  • , Buchwald and Hartwig on the use of monophosphine ligands in cross-coupling reactions, notably carbon–carbon ones such as the Mizoroki–Heck [1][2][3] and Suzuki–Miyaura reactions [4][5][6], there is a renewed interest for tertiary phosphines that favour the formation of singly phosphorus-ligated complexes
  • to prevent the coordination of a second phosphorus atom [13][14] or cavity-shaped phosphines [15]. The use of sterically-hindered P(III)-derivatives, notably phosphites [16][17][18][19][20][21], has also proven beneficial in yet another carbon–carbon forming reaction, namely the rhodium-catalysed
  • complexes with MX2 (M = Pd, Pt) fragments that normally form [ML2X2] complexes with tertiary phosphines. When reacted with HUGPHOS-1 in CH2Cl2, both [PdCl2(PhCN)2] and [PtCl2(PhCN)2] afforded a mixture of complexes (Scheme 2). The presence of a unique broad signal in each 31P{1H} NMR spectrum is consistent
PDF
Album
Supp Info
Full Research Paper
Published 15 Oct 2014

Chiral phosphines in nucleophilic organocatalysis

  • Yumei Xiao,
  • Zhanhu Sun,
  • Hongchao Guo and
  • Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

Graphical Abstract
  • phosphines possessing various chiral skeletons that have been used in asymmetric nucleophilic organocatalytic reactions, including annulations of allenes, alkynes, and Morita–Baylis–Hillman (MBH) acetates, carbonates, and ketenes with activated alkenes and imines, allylic substitutions of MBH acetates and
  • acylations of alcohols. Our discussion is organized according to the structural features of the chiral phosphines, the reaction types, and the nature of the substrate. Because chiral phosphine-promoted Rauhut–Currier (RC) reactions [9][10] and MBH/aza-MBH reactions [21][22][23][24][25][26] have been
  • of inherent air-sensitivity, the storage of trialkylphosphines can be problematic. On the other hand, thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions [27][28][29][30]. Most of these phosphines are acyclic, usually possess low nucleophilic activity
PDF
Album
Review
Published 04 Sep 2014

Organophosphorus chemistry

  • Paul R. Hanson

Beilstein J. Org. Chem. 2014, 10, 2087–2088, doi:10.3762/bjoc.10.217

Graphical Abstract
  • inhibitors. More specifically, the Thematic Series spans new methods in C–P bond formation, chiral phosphines in nucleophilic organocatalysis, chiral N-phosphinyl auxiliaries, cyclic phosphonamide reagents in the total synthesis of natural products, phosphinate-containing heterocycles, new routes to
PDF
Editorial
Published 04 Sep 2014

Rasta resin–triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions

  • Xuanshu Xia and
  • Patrick H. Toy

Beilstein J. Org. Chem. 2014, 10, 1397–1405, doi:10.3762/bjoc.10.143

Graphical Abstract
  • ], and have reported the use of various polymer-supported phosphines as reagents, organocatalysts, and ligands in order to simplify product isolation [14][15][16][17][18]. Most recently we have studied the use of the rasta resin polystyrene architecture [19][20][21][22][23][24][25][26] as a platform for
PDF
Album
Supp Info
Letter
Published 20 Jun 2014

Synthesis, characterization and DNA interaction studies of new triptycene derivatives

  • Sourav Chakraborty,
  • Snehasish Mondal,
  • Rina Kumari,
  • Sourav Bhowmick,
  • Prolay Das and
  • Neeladri Das

Beilstein J. Org. Chem. 2014, 10, 1290–1298, doi:10.3762/bjoc.10.130

Graphical Abstract
  • nm (ε: 5.37 × 104 M−1 cm−1 for 7 and 7.38 × 104 M−1 cm−1 for 8) are observed, similar to that in case of the ethynyl derivatives. However, the higher magnitude of the absorbance in the case of the phosphines relative to that of the ethynyl derivatives is due to the large number of phenyl groups
PDF
Album
Supp Info
Full Research Paper
Published 05 Jun 2014

Preparation of phosphines through C–P bond formation

  • Iris Wauters,
  • Wouter Debrouwer and
  • Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

Graphical Abstract
  • Iris Wauters Wouter Debrouwer Christian V. Stevens Research Group SynBioC, Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium 10.3762/bjoc.10.106 Abstract Phosphines are an important class of
  • ligands in the field of metal-catalysis. This has spurred the development of new routes toward functionalized phosphines. Some of the most important C–P bond formation strategies were reviewed and organized according to the hybridization of carbon in the newly formed C–P bond. Keywords: cross-coupling
  • ; enantioselectivity; hydrophosphination; organophosphorus chemistry; phosphines; phosphine-boranes; substitution reactions; trivalent phosphorus; Introduction Phosphines are an important class of organophosphorus compounds. They are often used as ligands in metal complex catalysis and they have become a popular
PDF
Album
Review
Published 09 May 2014

Staudinger ligation towards cyclodextrin dimers in aqueous/organic media. Synthesis, conformations and guest-encapsulation ability

  • Malamatenia D. Manouilidou,
  • Yannis G. Lazarou,
  • Irene M. Mavridis and
  • Konstantina Yannakopoulou

Beilstein J. Org. Chem. 2014, 10, 774–783, doi:10.3762/bjoc.10.73

Graphical Abstract
  • ) satisfactory aqueous solubility and independent binding capacity of the cavities. Keywords: calculations; conformations; cyclodextrin; dimer; inclusion; PM3; Staudinger ligation; Introduction The Staudinger reaction [1] is a classical method for the preparation of amines from phosphines and azides [2][3
PDF
Album
Supp Info
Full Research Paper
Published 03 Apr 2014

Copper–phenanthroline catalysts for regioselective synthesis of pyrrolo[3′,4′:3,4]pyrrolo[1,2-a]furoquinolines/phenanthrolines and of pyrrolo[1,2-a]phenanthrolines under mild conditions

  • Rupankar Paira,
  • Tarique Anwar,
  • Maitreyee Banerjee,
  • Yogesh P. Bharitkar,
  • Shyamal Mondal,
  • Sandip Kundu,
  • Abhijit Hazra,
  • Prakas R. Maulik and
  • Nirup B. Mondal

Beilstein J. Org. Chem. 2014, 10, 692–700, doi:10.3762/bjoc.10.62

Graphical Abstract
  • summarized in Table 1, revealed the supremacy of copper catalysts in this particular reaction over the others; CuCl2 appeared to be the catalyst of choice (Table 1, entries 8–32). In order to explore the effect of ligands, a number of phosphines, bis-oxazocines, pyrazolyl-pyrimidines and phenanthroline
  • analogues were employed (Figure 1). As represented in Table 1, the monodentate ligands are in general less effective (55–58% yield; Table 1, entries 21–25) than bi-/tridentate ligands (65–94% yield; Table 1, entries 26–32), and phosphines in general proved less effective in terms of product yield (Table 1
PDF
Album
Supp Info
Full Research Paper
Published 20 Mar 2014
Other Beilstein-Institut Open Science Activities