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Search for "organometallic complexes" in Full Text gives 31 result(s) in Beilstein Journal of Organic Chemistry.
Atherton–Todd reaction: mechanism, scope and applications
- Stéphanie S. Le Corre,
- Mathieu Berchel,
- Hélène Couthon-Gourvès,
- Jean-Pierre Haelters and
- Paul-Alain Jaffrès
Beilstein J. Org. Chem. 2014, 10, 1166–1196, doi:10.3762/bjoc.10.117
- et al. [95] reports the amination of either triaryl phosphate or dialkyl aryl phosphate catalyzed by nickel organometallic complexes. It is an additional illustration of the use of aryl phosphate, which can be readily obtained by AT reactions. Beside the use of phosphorus species as a substrate in
Graphical Abstract
Scheme 1: Pioneer works of Atherton, Openshaw and Todd reporting on the synthesis of phosphoramidate starting...
Scheme 2: Mechanisms 1 (i) and 2 (ii) suggested by Atherton and Todd in 1945; adapted from [1].
Scheme 3: Two reaction pathways (i and ii) to produce chlorophosphate 2. Charge-transfer complex observed whe...
Scheme 4: Mechanism of the Atherton–Todd reaction with dimethylphosphite according to Roundhill et al. (adapt...
Scheme 5: Synthesis of dialkyl phosphate from dialkyl phosphite (i) and identification of chloro- and bromoph...
Scheme 6: Synthesis of chiral phosphoramidate with trichloromethylphosphonate as the suggested intermediate (...
Scheme 7: Selection of results that address the question of the stereochemistry of the AT reaction (adapted f...
Scheme 8: Synthesis of phenoxy spirophosphorane by the AT reaction (adapted from [34]).
Scheme 9: Suggested mechanism of the Atherton–Todd reaction, (i) and (ii) formation of chlorophosphate with a...
Scheme 10: AT reaction in biphasic conditions (adapted from [38]).
Scheme 11: AT reaction with iodoform as halide source (adapted from [37]).
Scheme 12: AT reaction with phenol at low temperature in the presence of DMAP (adapted from [40]).
Scheme 13: Synthesis of a triphosphate by the AT reaction starting with the preparation of chlorophosphate (ad...
Scheme 14: AT reaction with sulfonamide (adapted from [42]).
Scheme 15: Synthesis of a styrylphosphoramidate starting from the corresponding aniline (adapted from [43]).
Scheme 16: Use of hydrazine as nucleophile in AT reactions (adapted from [48]).
Scheme 17: AT reaction with phenol as a nucleophilic species; synthesis of dioleyl phosphate-substituted couma...
Scheme 18: Synthesis of β-alkynyl-enolphosphate from allenylketone with AT reaction (adapted from [58]).
Scheme 19: Synthesis of pseudohalide phosphate by using AT reaction (adapted from [67]).
Scheme 20: AT reaction with hydrospirophosphorane with insertion of CO2 in the product (adapted from [69]).
Scheme 21: AT reaction with diaryl phosphite (adapted from [70]).
Scheme 22: AT reaction with O-alkyl phosphonite (adapted from [71]).
Scheme 23: Use of phosphinous acid in AT reactions (adapted from [72]).
Scheme 24: AT reaction with secondary phosphinethiooxide (adapted from [76]).
Scheme 25: Use of H-phosphonothioate in the AT reaction (adapted from [78]).
Scheme 26: AT-like reaction with CuI as catalyst and without halide source (adapted from [80]).
Scheme 27: Reduction of phenols after activation as phosphate derivatives (adapted from [81] i ; [82], ii; and [83], iii).
Scheme 28: Synthesis of medium and large-sized nitrogen-containing heterocycles (adapted from [85]).
Scheme 29: Synthesis of arylstannane from aryl phosphate prepared by an AT reaction (adapted from [86]).
Scheme 30: Synthesis and use of aryl dialkyl phosphate for the synthesis of biaryl derivatives (adapted from [89])....
Scheme 31: Synthesis of aryl dialkyl phosphate by an AT reaction from phenol and subsequent rearrangement yiel...
Scheme 32: Selected chiral phosphoramidates used as organocatalyst; i) chiral phosphoramidate used in the pion...
Scheme 33: Determination of ee of H-phosphinate by the application of the AT reaction with a chiral amine (ada...
Scheme 34: Chemical structure of selected flame retardants synthesized by AT reactions; (BDE: polybrominated d...
Scheme 35: Transformation of DOPO (i) and synthesis of polyphosphonate (ii) by the AT reaction (adapted from [117] ...
Scheme 36: Synthesis of lipophosphite (bisoleyl phosphite) and cationic lipophosphoramidate with an AT reactio...
Scheme 37: Use of AT reactions to produce cationic lipids characterized by a trimethylphosphonium, trimethylar...
Scheme 38: Cationic lipid synthesized by the AT reaction illustrating the variation of the structure of the li...
Scheme 39: Helper lipids for nucleic acid delivery synthesized with the AT reaction (adapted from [130]).
Scheme 40: AT reaction used to produce red/ox-sensitive cationic lipids (adapted from [135]).
Scheme 41: Alkyne and azide-functionalized phosphoramidate synthesized by AT reactions,(i); illustration of so...
Scheme 42: Cationic lipids exhibiting bactericidal action – arrows indicate the bond formed by the AT reaction...
Scheme 43: β-Cyclodextrin-based lipophosphoramidates (adapted from [138]).
Scheme 44: Polyphosphate functionalized by an AT reaction (adapted from [139]).
Scheme 45: Synthesis of zwitterionic phosphocholine-bound chitosan (adapted from [142]).
Scheme 46: Synthesis of AZT-based prodrug via an AT reaction (adapted from [143]).
Metal and metal-free photocatalysts: mechanistic approach and application as photoinitiators of photopolymerization
- Jacques Lalevée,
- Sofia Telitel,
- Pu Xiao,
- Marc Lepeltier,
- Frédéric Dumur,
- Fabrice Morlet-Savary,
- Didier Gigmes and
- Jean-Pierre Fouassier
Beilstein J. Org. Chem. 2014, 10, 863–876, doi:10.3762/bjoc.10.83
- organometallic complexes are mostly employed as radical sources: they exhibit an excellent visible-light absorption, long lived excited states and suitable redox potentials and they work through either an oxidation or a reduction cycle [1][2][3][4][5][6][7][8][9][10][11][12]. To avoid, however, the high cost
Graphical Abstract
Scheme 1: Examples of photoinitiating systems.
Figure 1: Previously reported PIC (based on metal complexes) [45-52].
Figure 2: Previously reported PIC (metal free organic molecules) [54,55].
Scheme 2: Reaction mechanisms for the three-component system PIC/eA/E-Z.
Scheme 3: Reaction mechanisms for the two-component system PIC/eA.
Scheme 4: Reaction mechanisms for the system PIC/eA/add.
Scheme 5: Reaction mechanisms for the system PIC/eD/B-Y.
Figure 3: Typical oxidation and reduction agents used through the photoredox catalysis approach in polymeriza...
Figure 4: Typical monomers that can be polymerized through a photoredox catalysis approach.
Scheme 6: Reaction mechanisms for the system Ru(bpy)32+/Ph2I+/R3SiH.
Scheme 7: Reaction mechanisms for the Ru(ligand)32+/Ph3S+/R3SiH system.
Scheme 8: Reaction mechanisms for the Ru(ligand)32+/Ph2I+/NVK system upon visible lights.
Scheme 9: Reaction mechanisms for the violanthrone/Ph2I+/TTMSS (R3SiH) system upon red lights.
Scheme 10: Reaction mechanisms for the Tr-AD/R-Br/MDEA system upon visible lights.
Scheme 11: The photoredox catalysis for controlled polymerization reactions.
Scheme 12: Reaction mechanisms for the Ru(ligand)32+/MDEA/R-Br system upon visible lights.
Scheme 13: Reaction mechanisms for the Violanthrone/Ru(ligand)32+/Ph2I+/R3SiH system upon visible lights.
Scheme 14: Reaction mechanisms for the MK/amine/triazine system upon visible lights.
Figure 5: The new proposed PIC (Ir(piq)2(tmd)).
Figure 6: UV–visible light absorption spectra for Ir(piq)2(tmd) (2) and Ir(ppy)3 (1); solvent: acetonitrile.
Figure 7: (A) cyclic voltamogramm for Ir(piq)2(tmd) in acetonitrile; (B) absorption (a) and luminescence (b) ...
Figure 8: Photolysis of a Ir(piq)2(tmd)/Ph2I+ solution ([Ph2I+] = 0.023 M, in acetonitrile) upon a halogen la...
Figure 9: ESR spin-trapping spectra for the irradiation of a Ir(piq)2(tmd)/Ph2I+ solution in the presence of ...
Figure 10: (A) Photopolymerization profile of EPOX; photoinitiating system: Ir(piq)2(tmd)/Ph2I+/NVK (1%/2%/3%)...
Figure 11: (A) Photopolymerization profile of TMPTA; initiating systems: (1) Ir(piq)2(tmd)/MDEA (1%/2%) and (2...
True and masked three-coordinate T-shaped platinum(II) intermediates
- Manuel A. Ortuño,
- Salvador Conejero and
- Agustí Lledós
Beilstein J. Org. Chem. 2013, 9, 1352–1382, doi:10.3762/bjoc.9.153
- been invoked as crucial intermediates in reactions involving late transition-metal complexes. Ligand dissociation, forming intermediates with open coordination sites, has been proposed as the initial step in many reactions involving square-planar d8 organometallic complexes [1]. Four-coordinate square
Graphical Abstract
Figure 1: Qualitative orbital diagram for a d8 metal in ML4 square-planar and ML3 T-shaped complexes.
Figure 2: Walsh diagram for the d-block of a d8 ML3 complex upon bending of one L–M–L angle.
Figure 3: Neutral Y-shaped Pt complex Y1 [15]. Angles are given in degrees.
Figure 4: General classification of T-shaped Pt(II) structures according to the fourth coordination site.
Figure 5: Hydride, boryl and borylene true T-shaped Pt(II) complexes.
Figure 6: NHC-based true T-shaped Pt(II) complexes.
Figure 7: Phosphine-based agostic T-shaped Pt(II) complexes. Compounds in brackets correspond with hydrido–al...
Figure 8: Phenylpyridine and NHC-based agostic T-shaped Pt(II) complexes.
Figure 9: Counteranion coordination in T-shaped Pt(II) complexes.
Figure 10: Phosphine-based solvento Pt(II) complexes.
Figure 11: Nitrogen-based solvento Pt(II) complexes.
Figure 12: Pincer-based solvento Pt(II) complexes.
Figure 13: Structure of the QM/MM optimized cisplatin–protein adduct [94].
Figure 14: NMR coupling constants used for the characterization of three-coordinate Pt(II) species.
Figure 15: The chemical formula of the complexes discussed in Table 2.
Scheme 1: Halogen abstraction from 1.
Scheme 2: Halogen abstraction from 2 forming the dicationic complex T3 [22].
Scheme 3: Hydrogenation of complexes A5a and A5b [39].
Scheme 4: Hydrogenation of complexes 3 and A5c [40].
Scheme 5: Intermolecular C–H bond activation from T5a [28].
Scheme 6: Protonation of complexes 4 [35,36].
Scheme 7: Cyclometalation of 5 [43].
Scheme 8: Protonation of 6.
Scheme 9: Reductive elimination of ethane from 7.
Scheme 10: Reductive elimination of methane from six-coordinate Pt(IV) complexes.
Scheme 11: Proposed dissociative mechanism for the fluxional motion of dmphen in [Pt(Me)(dmphen)(PR3)]+ comple...
Figure 16: Feasible interactions for unsaturated intermediates 11b (left) and 12b (right) during fluxional mot...
Scheme 12: Halogen abstraction from 13a,b and subsequent cyclometalation to yield complexes A5a,b [39].
Scheme 13: Proposed mechanism for the acid-catalyzed cyclometalation of 14 via intermediate 15 [41].
Scheme 14: Proposed mechanism for the formation of 19 [102].
Scheme 15: Cyclometalation of 20 via thioether dissociation [117].
Figure 17: Gibbs energy profile (in chloroform solvent) for the cyclometalation of 23 [120].
Scheme 16: Coordination of tmtu to 29 and subsequent C–H bond activation via three-coordinate species 31 and 32...
Scheme 17: Cyclometalation process of NHC-based Pt(II) complexes [28,44].
Scheme 18: Cyclometalation process of complex A9 [43].
Scheme 19: “Rollover” reaction of 38 and subsequent oligomerization [123].
Scheme 20: Proposed mechanism for the formation of cyclometalated species 44 [124].
Scheme 21: Self-assembling process of 45 by “rollover” reaction [126].
Scheme 22: “Rollover” reaction of A9. Energies (solvent) in kcal mol−1 [127].
Scheme 23: Proposed mechanisms for the “rollover” cyclometalation of 52 in gas-phase ion-molecule reactions [128].
Scheme 24: β-H elimination and 1,2-insertion equilibrium involving A1d and the subsequent generation of 57 [35].
Scheme 25: Proposed mechanism for thermolysis of 7b and 7c in benzene-d6 and cyclohexane-d12 solvents [101].
Scheme 26: β-H elimination process of A11a [28].
Scheme 27: Intermolecular C–H bond activation from 62 [95].
Scheme 28: Reductive elimination of methane from 65 followed by CD3CN coordination or C–D bond-activation proc...
Figure 18: DFT-optimized structures describing the κ2 (69, left) and κ3 (69’, right) coordination modes of [Pt...
Scheme 29: Intermolecular arene C–H bond activation from NHC-based complexes [28].
Figure 19: Energy profiles (in benzene solvent) for the benzene C–H bond activation from A11a, A11b, T5a and T...
Scheme 30: Intermolecular arene C–H bond activation from PNP-based complex 71 [12].
Scheme 31: Intermolecular C–H bond-activation by gas-phase ion-molecule reactions of 74 [7,142].
Scheme 32: Dihydrogen activation through complexes A5a, A5b [39], A5c [40] and S1a [54].
Scheme 33: Dihydrogen activation through complexes A7 and 16 [41]. For a: see Scheme 13.
Scheme 34: Br2 and I2 bond activations through complexes A11a and T5a [143].
Scheme 35: Detection and isolation of the Pt(III) complex 81a [143].
Scheme 36: Cl2 bond activation through complexes 82 and 83 [144].
Scheme 37: cis–trans Isomerization mechanism of the solvento Pt(II) complexes S5 [2,61].
Figure 20: Energy profiles for the isomerization of complexes [Pt(R)(PMe3)2(NCMe)]+ where R means Me (85a, red...
Figure 21: DFT-optimized structure of intermediate 86 [62]. Bond distances in angstrom and angles in degrees.
Scheme 38: Proposed dissociative ligand-substitution mechanism of cis-[Pt(R)2S2] complexes (87) [117].
Scheme 39: Proposed mechanisms for the ligand substitution of the dinuclear species 91 [146].
Dimerization of a cell-penetrating peptide leads to enhanced cellular uptake and drug delivery
- Jan Hoyer,
- Ulrich Schatzschneider,
- Michaela Schulz-Siegmund and
- Ines Neundorf
Beilstein J. Org. Chem. 2012, 8, 1788–1797, doi:10.3762/bjoc.8.204
- (cymantrene) complexes to tumor cell lines, inducing high cellular toxicity. In order to increase the potential of the organometallic complexes to kill tumor cells, we were looking for a way to enhance cellular uptake. Therefore, we designed a branched dimeric variant of sC18, (sC18)2, which was shown to have
- a cell-penetrating peptide. Keywords: anti-tumor agents; cell-penetrating peptides; drug delivery; internalization studies; organometallic complexes; peptides; Introduction A substantial problem concerning promising drug candidates is often their incapacity to reach their full therapeutic
- pronounced after introduction of an enzymatic cleavage site [12]. However, the aim of the present study was to investigate whether the cytotoxic effect of these organometallic complexes can be further increased by conjugating them to a dimeric variant of sC18, (sC18)2, since previous studies demonstrated
Graphical Abstract
Figure 1: Flow cytometric uptake studies of carboxyfluorescein-labeled (sC18)2 in HEK-293 (human embryonic ki...
Figure 2: Top: Fluorescence microscopic images of unfixed HEK-293 cells after 30 min incubation with 1 µM CF-...
Figure 3: Cell viability of different cell lines after 24 h incubation with (sC18)2 at different concentratio...
Figure 4: Cell lysis of HEK-293 cells induced by (sC18)2 after 1 h incubation. Experiments were conducted in ...
Scheme 1: Synthesis of (sC18)2 bioconjugates (a) and chemical structures of the coupled anti-tumor agents (b)...
Figure 5: Chromatogram and ESI-MS of purified Cym2-GFL-(sC18)2. The gradient was 10→60% acetonitrile in water...
Figure 6: Circular dichroism spectra of the (sC18)2 conjugates. Spectra were acquired in 10 mM phosphate buff...
Figure 7: Cell viability of (a) HT-29 and (b) MCF-7 cells after 24 h incubation with the (sC18)2 conjugates a...
Figure 8: Brightfield microscopic images of unfixed HT-29 cells after 24 h incubation with the (sC18)2 conjug...
Figure 9: Cell lysis of (a) HT-29 and (b) MCF-7 cells induced by the (sC18)2 conjugates at different concentr...
Meta-metallation of N,N-dimethylaniline: Contrasting direct sodium-mediated zincation with indirect sodiation-dialkylzinc co-complexation
- David R. Armstrong,
- Liam Balloch,
- Eva Hevia,
- Alan R. Kennedy,
- Robert E. Mulvey,
- Charles T. O'Hara and
- Stuart D. Robertson
Beilstein J. Org. Chem. 2011, 7, 1234–1248, doi:10.3762/bjoc.7.144
- -complexation approaches. The results of this study highlight the inherent complexity of these metallation reactions even at the metal stage, with a diverse array of organometallic complexes isolated, prior to the recognised intricacies of subsequent electrophilic interception. Collectively, these results
Graphical Abstract
Scheme 1: Proposed stepwise mechanism for the zincation of benzene.
Figure 1: Molecular structure of 2 with selective atom labelling. Hydrogen atoms and minor disorder component...
Scheme 2: Synergic metallation of N,N-dimethylaniline (A) with sodium TMP-zincate 1 to produce 2, which was s...
Figure 2: Molecular structure of 3 with selective atom labelling and thermal ellipsoids drawn at the 50% prob...
Scheme 3: Indirect zincation of N,N-dimethylaniline producing 4, 5 and 6, which was then quenched with I2 to ...
Figure 3: Molecular structure of 4 with selective atom labelling and thermal ellipsoids drawn at the 50% prob...
Figure 4: Solvent-separated ion-pair structure of 5 with selective atom labelling and thermal ellipsoids draw...
Figure 5: Molecular structure of 6 with selective atom labelling and thermal ellipsoids drawn at the 50% prob...
Figure 6: Aromatic region of 1H NMR spectra for deuterated benzene solutions of (a) the crude mixture obtaine...
Figure 7: Relative energy sequence of the four theoretical regioisomers of the experimentally observed produc...
Stereoselectivity of supported alkene metathesis catalysts: a goal and a tool to characterize active sites
- Christophe Copéret
Beilstein J. Org. Chem. 2011, 7, 13–21, doi:10.3762/bjoc.7.3
- –inorganic materials [43], where surface functionalities such as typical organic ligands are perfectly distributed within the pore networks of a mesoporous silica. For other approaches used to prepare supported homogeneous catalysts, see the reviews [44][45][46]. Selective grafting of organometallic
- complexes onto these pendant ligands can then be performed. Using this technology, several materials containing N-heterocyclic metal units (M–NHC) have been prepared, including a system containing a Ru–NHC unit (Scheme 5), which displayed unprecedented activity in the metathesis of ethyl oleate with
Graphical Abstract
Scheme 1: Alkene metathesis mechanism.
Scheme 2: Metathesis possibilities.
Scheme 3: Metathesis with Re-based alumina supported catalysts.
Figure 1: (E/Z) ratio as a function of conversion. a) MeReO3 supported on alumina and b) MeReO3 supported on ...
Scheme 4: Alkene selectivity of metathesis reactions.
Scheme 5: Hybrid organic–inorganic catalyst containing a Ru–NHC unit.
