Organometallic chemistry

Editors: Prof. Bernd F. Straub and Prof. Lutz Gade
Universität Heidelberg

Over a period of many decades, the chemistry of metal–carbon bonds has given rise to an ever-growing field of fundamental research and applied science, merging the reactivity of inorganic complexes with the structural diversity of organic compounds. The contributions in this Thematic Series reflect the broad impact of organometallic compounds in various fields of modern chemical research. These include the tailoring of new ancillary ligands, the investigation of more active and more selective homogeneous catalysts, catalytic transformations in the total synthesis of natural products, the theoretical and kinetic unravelling of reaction mechanisms, and the verification of rare coordination modes. These various facets underline the importance of organometallic chemistry in its own right, but also demonstrate the vital role that research in organometallic chemistry plays as a provider of invaluable tools for other chemistry sub-disciplines.

Organometallic chemistry

Bernd F. Straub,
Rolf Gleiter,
Claudia Meier and
Lutz H. Gade

Editorial
Published 19 Oct 2016

PDF
Album
1. Figure 1: Peter Hofmann.
  
  Jump to Figure 1

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 2216–2221, doi:10.3762/bjoc.12.213

Full Text

A modular approach to neutral P,N-ligands: synthesis and coordination chemistry

Vladislav Vasilenko,
Torsten Roth,
Clemens K. Blasius,
Sebastian N. Intorp,
Hubert Wadepohl and
Lutz H. Gade

Full Research Paper
Published 29 Apr 2016

PDF
Album
1. Graphical Abstract
2. Figure 1: P,N-ligand frameworks studied in this work.
  
  Jump to Figure 1
3. Scheme 1: Synthesis of N-phosphanylformamidines 2 and 3. Reaction conditions: (i) t-BuLi, THF, −78 °C to rt, ...
  
  Jump to Scheme 1
4. Scheme 2: Synthesis of phosphanylformamidines 5 and 7. Reaction conditions: (i) t-BuLi, THF, −78 °C to rt, 1 ...
  
  Jump to Scheme 2
5. Scheme 3: Synthesis of complexes [2-M(cod)]X, [3-M(cod)]X, [5-M(cod)]X and [7-M(cod)]X. M = Rh, Ir; X = BF₄⁻ ...
  
  Jump to Scheme 3
6. Figure 2: Molecular structures of [2a-Rh(cod)]⁺ (A), [5-Ir(cod)]⁺ (B), and [7-Rh(cod)]⁺ (C,D). Anisotropic di...
  
  Jump to Figure 2
7. Figure 3: Coordination of ligands 2a and 5 to Rh(III) and Ir(III) precursors. Yields: [2a-Cp*RhCl]BF₄ = 87%, [...
  
  Jump to Figure 3
8. Figure 4: Molecular structures of [2a-Cp*IrI]⁺ (left) and [5-Cp*IrI]⁺ (right). Anisotropic displacement ellip...
  
  Jump to Figure 4
9. Figure 5: Formation of palladium complexes of ligands 2a, 5 and 7. (A) Formation of [2a-PdCl₂] and [2a-PdCl]₂...
  
  Jump to Figure 5
10. Figure 6: Molecular structures of [2a-PdCl₂] (left) and [5-Pd(2-Me-allyl)]⁺ (right). Anisotropic displacement...
  
  Jump to Figure 6
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 846–853, doi:10.3762/bjoc.12.83

Full Text

Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

Sebastian Bretzke,
Stephan Scheeff,
Felicitas Vollmeyer,
Friederike Eberhagen,
Frank Rominger and
Dirk Menche

Full Research Paper
Published 02 Jun 2016

PDF
Album
1. Graphical Abstract
2. Figure 1: Modular concept for manzacidin synthesis based on a Tsuji–Trost coupling of joint intermediate 5.
  
  Jump to Figure 1
3. Scheme 1: General concept for heterocycles synthesis based on a nucleophilic addition and Tsuji–Trost couplin...
  
  Jump to Scheme 1
4. Scheme 2: Synthesis of homoallylic alcohol 12 by multi-component reactions.
  
  Jump to Scheme 2
5. Scheme 3: Preparation of urea-type cyclization precursor 19.
  
  Jump to Scheme 3
6. Scheme 4: Stereodivergent synthesis of 1,3-syn- and anti-tetrahydropyrimidinones [31].
  
  Jump to Scheme 4
7. Scheme 5: Stereoselective synthesis of all possible stereoisomers of the manzacidin core amine by asymmetric ...
  
  Jump to Scheme 5
8. Scheme 6: Synthesis of the authentic cyclization precursor 5.
  
  Jump to Scheme 6
9. Figure 2: X-ray structure of 39.
  
  Jump to Figure 2
10. Scheme 7: Divergent Tsuji–Trost coupling and completion of the synthesis of authentic pyrimidinones 3 and 4.
  
  Jump to Scheme 7
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 1111–1121, doi:10.3762/bjoc.12.107

Full Text

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

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

Full Research Paper
Published 07 Jun 2016

PDF
Album
1. Graphical Abstract
2. Scheme 1: Divergent behavior of the palladium and ruthenium-catalyzed Alder–ene reaction.
  
  Jump to Scheme 1
3. Scheme 2: Some asymmetric enyne cycloisomerization reactions.
  
  Jump to Scheme 2
4. Figure 1: (a) Mechanism for the redox biscycloisomerization reaction. (b) Ruthenium catalyst containing a tet...
  
  Jump to Figure 1
5. Scheme 3: Synthesis of p-anisyl catalyst 1.
  
  Jump to Scheme 3
6. Figure 2: Failed sulfinate ester syntheses.
  
  Jump to Figure 2
7. Scheme 4: Using norephedrine-based oxathiazolidine-2-oxide 7 for chiral sulfoxide synthesis.
  
  Jump to Scheme 4
8. Scheme 5: (a) General synthetic sequence to access enyne bicycloisomerization substrates (b) Synthesis of 2-c...
  
  Jump to Scheme 5
9. Figure 3: Failed bicycloisomerization substrates. Reactions performed at 40 °C for 16 hours with 3 mol % of c...
  
  Jump to Figure 3
10. Scheme 6: Deprotection of [3.1.0] bicycles and X-ray crystal structure of 76.
  
  Jump to Scheme 6
11. Scheme 7: ProPhenol-catalyzed addition of zinc acetylide to acetaldehyde for the synthesis of a chiral 1,6-en...
  
  Jump to Scheme 7
12. Figure 4: Diastereomeric metal complexes formed after alcohol coordination.
  
  Jump to Figure 4
13. Scheme 8: Curtin–Hammitt scenario of redox bicycloisomerization in acetone.
  
  Jump to Scheme 8
Supp. Info

Graphical Abstract

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

Full Text

Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

Jakub Saadi,
Christoph Bentz,
Kai Redies,
Dieter Lentz,
Reinhold Zimmer and
Hans-Ulrich Reissig

Full Research Paper
Published 16 Jun 2016

PDF
Album
1. Graphical Abstract
2. Scheme 1: Planned Heck reaction of A to compound B and serendipitous discovery of the palladium-catalyzed cyc...
  
  Jump to Scheme 1
3. Scheme 2: Synthesis of compounds A (1–6) via methyl 2-siloxycyclopropanecarboxylates D, their alkylation to E...
  
  Jump to Scheme 2
4. Scheme 3: Palladium-catalyzed reactions of methyl ketone 1 to tetralin derivative 7 and of isopropyl-substitu...
  
  Jump to Scheme 3
5. Scheme 4: Palladium-catalyzed cyclization of diastereomeric cyclopentanone derivatives 3a/3b to products 11a ...
  
  Jump to Scheme 4
6. Figure 1: Molecular structure (ORTEP, [14]) of compound 12a (thermal ellipsoids at 50% probability).
  
  Jump to Figure 1
7. Scheme 5: Palladium-catalyzed cyclizations of diastereomeric cyclohexanone derivatives 4a and 4b leading ster...
  
  Jump to Scheme 5
8. Figure 2: Molecular structure (ORTEP, [14]) of compound 14a (thermal ellipsoids at 50% probability).
  
  Jump to Figure 2
9. Scheme 6: Palladium-catalyzed cyclizations of cycloheptanone derivatives 5a and 5b leading to products 15a an...
  
  Jump to Scheme 6
10. Figure 3: Molecular structure (ORTEP, [14]) of compound 15a (thermal ellipsoids at 50% probability).
  
  Jump to Figure 3
11. Figure 4: Molecular structure (ORTEP [14]) of compound 15b (thermal ellipsoids at 50% probability).
  
  Jump to Figure 4
12. Scheme 7: Palladium-catalyzed cyclization of p-methoxy-substituted aryl iodide 6a/6b to compound 16.
  
  Jump to Scheme 7
13. Scheme 8: Typical palladium-catalyzed cyclization of an o-iodoaniline derivative to a tricyclic tertiary alco...
  
  Jump to Scheme 8
14. Scheme 9: Proposed transition state (TS) explaining the stereoselective formation of cyclization products.
  
  Jump to Scheme 9
15. Scheme 10: Possible mechanism of the reduction of palladium(II) to palladium(0) by triethylamine (additional l...
  
  Jump to Scheme 10
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 1236–1242, doi:10.3762/bjoc.12.118

Full Text

Artificial Diels–Alderase based on the transmembrane protein FhuA

Hassan Osseili,
Daniel F. Sauer,
Klaus Beckerle,
Marcus Arlt,
Tomoki Himiyama,
Tino Polen,
Akira Onoda,
Ulrich Schwaneberg,
Takashi Hayashi and
Jun Okuda

Full Research Paper
Published 24 Jun 2016

PDF
Album
1. Graphical Abstract
2. Scheme 1: Syntheses to Cu(I) complex bearing a NHC ligand.
  
  Jump to Scheme 1
3. Scheme 2: Synthesis of Cu(II) terpyridyl complexes.
  
  Jump to Scheme 2
4. Scheme 3: Anchoring and refolding of the biohybrid copper complexes.
  
  Jump to Scheme 3
5. Figure 1: CD spectra of refolded catalysts 17–19 (red: 17, black: 18, blue: 19).
  
  Jump to Figure 1
6. Figure 2: Temperature-dependent CD spectra of catalyst 17.
  
  Jump to Figure 2
7. Figure 3: MALDI–TOF mass spectra (black: 17, red: FhuAΔCVF^tev).
  
  Jump to Figure 3
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 1314–1321, doi:10.3762/bjoc.12.124

Full Text

On the mechanism of imine elimination from Fischer tungsten carbene complexes

Philipp Veit,
Christoph Förster and
Katja Heinze

Full Research Paper
Published 27 Jun 2016

PDF
Album
1. Graphical Abstract
2. Scheme 1: Imine formation and isomerization reactions from NH carbene complexes Cr(CO)₅(E-2) (a) [27], Cr(CO)₅(E/Z...
  
  Jump to Scheme 1
3. Scheme 2: Synthesis of W(CO)₅(E-2) from W(CO)₅(1^Et) [20,21] and aminoferrocene [40,41] with concomitant formation of E-1,2-...
  
  Jump to Scheme 2
4. Scheme 3: Reaction pathways 1a/1b (migration–elimination) and 2a/2b (elimination–migration) for the formation...
  
  Jump to Scheme 3
5. Scheme 4: Reaction pathways 3a/3b/3c (CO dissociation) for the formation of imine E-3 from W(CO)₅(E-2).
  
  Jump to Scheme 4
6. Figure 1: DFT calculated oxidative addition/pseudorotation/reductive elimination pathway 3c from W(CO)₄(E-2) ...
  
  Jump to Figure 1
7. Figure 2: DFT calculated geometries of the two hydrido intermediates cis(N,H)-W(CO)₄(H)(Z-15) and cis(C,H)-W(...
  
  Jump to Figure 2
8. Scheme 5: Proposed reaction sequence from W(CO)₅(E-2) to W(CO)₅(PPh₃) in the presence of triphenylphosphane.
  
  Jump to Scheme 5
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

Full Text

Molecular weight control in organochromium olefin polymerization catalysis by hemilabile ligand–metal interactions

Stefan Mark,
Hubert Wadepohl and
Markus Enders

Full Research Paper
Published 04 Jul 2016

PDF
Album
1. Graphical Abstract
2. Scheme 1: Influencing catalyst stability, olefin coordination and chain-transfer reactions by hemilabile dono...
  
  Jump to Scheme 1
3. Scheme 2: Synthesis of ligands L1–L8 and chromium complexes 1–8.
  
  Jump to Scheme 2
4. Figure 1: Solid-state molecular structures of selected complexes 4, 7 and 8 (left, middle and right, respecti...
  
  Jump to Figure 1
5. Figure 2: a) Calculated structures of cationic chromium complexes. Chromium–donor distances [Å]: 3a⁺ [2.21], ...
  
  Jump to Figure 2
6. Figure 3: Comparison of GPC traces of polyethylene produced by 1/PMAO and 8/PMAO respectively (entries 1 and ...
  
  Jump to Figure 3
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 1372–1379, doi:10.3762/bjoc.12.131

Full Text

Ring-whizzing in polyene-PtL₂ complexes revisited

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

Full Research Paper
Published 07 Jul 2016

PDF
Album
1. Graphical Abstract
2. Figure 1: The four coordination geometries for d¹⁰ polyene-ML₂ complexes along with their hapto numbers and e...
  
  Jump to Figure 1
3. Figure 2: The important valence orbitals of a d¹⁰ ML₂ group, 5–7, along with the computed structures of Pt(PH₃...
  
  Jump to Figure 2
4. Figure 3: The empty degenerate set of π orbitals in the cyclopropenium cation is shown on the left side. On t...
  
  Jump to Figure 3
5. Figure 4: Two unoccupied MOs for Cp⁺ are shown on the left side. The two stationary points for Cp–Pt(dpe)⁺ ar...
  
  Jump to Figure 4
6. Figure 5: The half-filled degenerate π orbitals in cyclobutadiene. The computed ground state (15) and transit...
  
  Jump to Figure 5
7. Figure 6: The ground and transition state for ring whizzing in F₆C₆–Pt(dpe), 17 and 20, respectively. The dom...
  
  Jump to Figure 6
8. Figure 7: The LUMO, 23, and HOMO, 27, in 6-radialene. The optimized η² ground states are shown in 24 and 25 w...
  
  Jump to Figure 7
9. Figure 8: Two representations for the half-filled e_2u set of π orbitals in cyclooctatetraene.
  
  Jump to Figure 8
10. Figure 9: The stationary points found on the potential energy surface of C₈F₈–Pt(dpe). For clarity the groups...
  
  Jump to Figure 9
11. Figure 10: The two important bonding interactions for transition state 31 are drawn in 33 and 34.
  
  Jump to Figure 10
12. Figure 11: Three other coordination geometries that did not lead to new stationary points are shown in 35–37.
  
  Jump to Figure 11
13. Figure 12: The LUMO and LUMO+1 shown in 38 and 39, respectively. The four stationary points found for pentalen...
  
  Jump to Figure 12
14. Figure 13: The LUMO of the phenalenium cation is given in 44. The structures of the three stationary points fo...
  
  Jump to Figure 13
15. Figure 14: A top view of two stationary points found for F₈C₁₀–Pt(dpe); 48 is the ground state and 50, represe...
  
  Jump to Figure 14
16. Figure 15: At top view of the η⁴, 52, and η⁴, 54, transition states along with the η², 53, intermediate.
  
  Jump to Figure 15
Supp. Info

Graphical Abstract

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

Full Text

Stereodynamic tetrahydrobiisoindole “NU-BIPHEP(O)”s: functionalization, rotational barriers and non-covalent interactions

Golo Storch,
Sebastian Pallmann,
Frank Rominger and
Oliver Trapp

Full Research Paper
Published 14 Jul 2016

PDF
Album
1. Graphical Abstract
2. Figure 1: Synthetic overview of “NU-BIPHEP(O)s”. A) Rhodium catalyzed double [2 + 2 + 2] cycloaddition. B) Ac...
  
  Jump to Figure 1
3. Figure 2: Investigation of 3,5-dichlorobenzoyl modified tetrahydrobiisoindole “NU-BIPHEP(O)” 3. A) Three sign...
  
  Jump to Figure 2
4. Figure 3: Investigation of “NU-BIPHEP(O)” 1b. A) Solid-state structure determined by X-ray crystallography. H...
  
  Jump to Figure 3
5. Figure 4: Enantioselective DHPLC investigation of tetrahydrobiisoindole “NU-BIPHEP(O)” 3. A) Elution profiles...
  
  Jump to Figure 4
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 1453–1458, doi:10.3762/bjoc.12.141

Full Text

Methylpalladium complexes with pyrimidine-functionalized N-heterocyclic carbene ligands

Dirk Meyer and
Thomas Strassner

Full Research Paper
Published 21 Jul 2016

PDF
Album
1. Graphical Abstract
2. Scheme 1: Synthesis of the monomethylpalladium(II) complexes 9–11 (in DCM) and 12 (in CH₃CN).
  
  Jump to Scheme 1
3. Figure 1: Possible isomers.
  
  Jump to Figure 1
4. Figure 2: ORTEP [39] style plot of complex 9 in the solid state. Thermal ellipsoids are given at the 50% probabil...
  
  Jump to Figure 2
5. Figure 3: ORTEP [39] style plot of complex 12 in the solid state. Thermal ellipsoids are drawn at the 50% probabi...
  
  Jump to Figure 3
6. Scheme 2: Synthesis of complex 13.
  
  Jump to Scheme 2
7. Figure 4: ORTEP [39] style plot of complex 13 in the solid state. Thermal ellipsoids are drawn at the 50% probabi...
  
  Jump to Figure 4
8. Scheme 3: Possible pathways of methyl trifluoroacetate formation starting from complex 13.
  
  Jump to Scheme 3
9. Scheme 4: Synthesis of complex 14 by conversion of complex 13 with iodobenzene bistrifluoroacetate.
  
  Jump to Scheme 4
10. Scheme 5: Synthesis of the [((pym)^(NHC-R))Pd^II(CH₃)₂] complex 15.
  
  Jump to Scheme 5
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 1557–1565, doi:10.3762/bjoc.12.150

Full Text

Dinuclear thiazolylidene copper complex as highly active catalyst for azid–alkyne cycloadditions

Anne L. Schöffler,
Ata Makarem,
Frank Rominger and
Bernd F. Straub

Full Research Paper
Published 21 Jul 2016

PDF
Album
1. Graphical Abstract
2. Scheme 1: Disfavored mononuclear pathway and favored dinuclear pathway in the CuAAC click reaction, according...
  
  Jump to Scheme 1
3. Figure 1: Ball-and-stick model [42,43] of a single crystal X-ray structure of hexafluorophosphate salt 1b (CCDC 1472...
  
  Jump to Figure 1
4. Scheme 2: Synthesis of dinuclear copper complex 2.
  
  Jump to Scheme 2
5. Figure 2: Time-conversion-diagram of the CuAAC reaction of benzyl azide with either phenylacetylene or ethyl ...
  
  Jump to Figure 2
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 1566–1572, doi:10.3762/bjoc.12.151

Full Text

A T-shape diphosphinoborane palladium(0) complex

Patrick Steinhoff and
Michael E. Tauchert

Letter
Published 22 Jul 2016

PDF
Album
1. Graphical Abstract
2. Figure 1: Selected M→B coordination modes 1–5 [6-10] and Hofmann’s Rucaphos complex 6 [11].
  
  Jump to Figure 1
3. Scheme 1: Synthesis of diphosphinoborane ^CyDPB^Ph and complex 9.
  
  Jump to Scheme 1
4. Figure 2: Thermal ellipsoid plots of complex 9 at the 50% probability level. H atoms and one molecule of hexa...
  
  Jump to Figure 2
Supp. Info

Graphical Abstract

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

Full Text

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

Michael Nonnenmacher,
Dominik M. Buck and
Doris Kunz

Full Research Paper
Published 23 Aug 2016

PDF
Album
1. Graphical Abstract
2. Figure 1: Left: resonance hybrid of the dipyrido carbenes dipiy and dipiy^tBu. Right: two canonical forms of t...
  
  Jump to Figure 1
3. Scheme 1: Preparation of the ¹³CO substituted rhodium complexes 2 bearing the dipyrido-annelated carbenes dip...
  
  Jump to Scheme 1
4. Figure 2: ¹³C NMR spectra (carbonyl region, 125 MHz) of the reaction of 1a with ¹³CO under variable pressure ...
  
  Jump to Figure 2
5. Scheme 2: Proposed mechanism for the preferred exchange of the cis-CO ligand based on DFT-calculations (BP86 ...
  
  Jump to Scheme 2
6. Figure 3: IR scale (cm⁻¹) to determine the overall electron-donor capacity of various N-heterocyclic carbenes...
  
  Jump to Figure 3
7. Figure 4: Highest occupied molecular orbitals for the dipyrido-annelated carbene dipiy. The σ-type carbene lo...
  
  Jump to Figure 4
8. Figure 5: Molecular orbitals of the Rh complexes II-Rh, III-Rh and 2a that show ligand-metal π-bonds.
  
  Jump to Figure 5
Supp. Info

Graphical Abstract

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

Full Text

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

Dominik Urselmann,
Konstantin Deilhof,
Bernhard Mayer and
Thomas J. J. Müller

Full Research Paper
Published 20 Sep 2016

PDF
Album
1. Graphical Abstract
2. Figure 1: Thienyl-bridged oligophenothiazines as topological hybrids of (oligo)phenothiazines and 2,5-di(hete...
  
  Jump to Figure 1
3. Scheme 1: One-pot bromine-lithium-exchange-borylation-Suzuki (BLEBS) synthesis of 7-bromo-substituted phenoth...
  
  Jump to Scheme 1
4. Scheme 2: Pseudo five-component Sonogashira-Glaser-cyclization synthesis of thienyl-bridged oligophenothiazin...
  
  Jump to Scheme 2
5. Figure 2: Cyclic voltammograms of compounds 3 (recorded in CH₂Cl₂, T = 293 K, electrolyte n-Bu₄N⁺PF₆⁻, Pt wor...
  
  Jump to Figure 2
6. Figure 3: UV–vis (solid lines) and fluorescence spectra (dashed lines) of the thienyl-bridged oligophenothiaz...
  
  Jump to Figure 3
7. Figure 4: DFT-calculated minimum conformer of the 2,5-bis(terphenothiazinyl)thiophene 3c (calculated with the...
  
  Jump to Figure 4
8. Figure 5: Relevant Kohn–Sham FMOs contributing to the S₁ states that are assigned to the longest wavelengths ...
  
  Jump to Figure 5
Supp. Info

Graphical Abstract

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

Full Text

Back to all Issues

Other Beilstein-Institut Open Science Activities

Keep Informed

RSS Feed

Subscribe to our Latest Articles RSS Feed.

Subscribe

Email Notification

Register and get informed about new articles.

Register

Follow the Beilstein-Institut

Twitter: @BeilsteinInst