Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

Christian Schumacher,
Jas S. Ward,
Kari Rissanen,
Carsten Bolm and
Mohamed Ramadan El Sayed Aly

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Published 27 Jan 2023

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1. Graphical Abstract
2. Figure 1: Chemical structure of three isomeric cholesterols.
  
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3. Figure 2: Selected previously described cholesterol derivatives with interesting antibacterial and cytotoxic ...
  
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4. Scheme 1: Stereochemical outcome of OH/N₃ transformations under different conditions.
  
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5. Figure 3: Top: cholesterol (1) and the less polar product from the Appel reaction, cholesta-3,5-diene (9); bo...
  
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6. Figure 4: Top: the more polar product from the Appel reaction 3β-bromocholest-5-ene (4); bottom: X-ray struct...
  
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7. Figure 5: Top: 3α-azidocholest-5-ene (5) obtained by treatment of 4 with NaN₃ in DMF; bottom: X-ray crystal s...
  
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8. Scheme 2: Mechanistic interpretation of the conversion of cholesterol 1 into diene 9, bromide 4, and azides 5...
  
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9. Figure 6: Compounds (next to 4, 5 and 9) to be corrected in refs. [10] and [11]. The respective bonds are highlighted...
  
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Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

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Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

Henrik Hupatz,
Marius Gaedke,
Hendrik V. Schröder,
Julia Beerhues,
Arto Valkonen,
Fabian Klautzsch,
Sebastian Müller,
Felix Witte,
Kari Rissanen,
Biprajit Sarkar and
Christoph A. Schalley

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Published 20 Oct 2020

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1. Graphical Abstract
2. Figure 1: Structures of the compounds used in this study: a) crown-8 analogs; b) crown-7 analogs; c) secondar...
  
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3. Scheme 1: Schematic representation of synthetic routes towards TTFC7, exTTFC7, NDIC7, and NDIC8.
  
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4. Figure 2: Solid-state structures of a) exTTFC7 (CH₃CN molecule omitted for clarity), b) NDIC7 (CH₃CN molecule...
  
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5. Figure 3: a) Synthesis of the [2]rotaxane NDIRot. b) Stacked ¹H NMR spectra (700 MHz, CDCl₃, 298 K) of NDIC8 ...
  
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6. Figure 4: UV–vis–NIR spectra obtained by spectroelectrochemical measurements (0.1 M n-Bu₄PF₆, CH₂Cl₂/CH₃CN 1:...
  
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Beilstein J. Org. Chem. 2020, 16, 2576–2588, doi:10.3762/bjoc.16.209

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Halogen bonding and host–guest chemistry between N-alkylammonium resorcinarene halides, diiodoperfluorobutane and neutral guests

Fangfang Pan,
Mohadeseh Dashti,
Michael R. Reynolds,
Kari Rissanen,
John F. Trant and
Ngong Kodiah Beyeh

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Published 18 Apr 2019

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1. Graphical Abstract
2. Figure 1: Tetravalent XB acceptor, Hex-NARBr 1, Cy-NARCl 2, divalent XB donor DIOFB, and guests MeCN, MeOH an...
  
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3. Figure 2: The previously reported halogen-bonded complexes CHCl₃@1&DIOFB (a), and MeOH@1&DIOFB (b). (c)The fi...
  
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4. Figure 3: The two dimerization modes in the MeOH-MeCN@1&DIOFB complex. In both modes, the cavities are shown ...
  
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5. Figure 4: (a) The halogen bonding (blue broken lines), hydrogen bonding (red broken lines) and the host–guest...
  
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6. Figure 5: ¹⁹F NMR in CDCl₃ at 298 K of: a) DIOFB (10 mM); b) 1:2 mixture of DIOFB and 1; 1:2:1 mixture of DIO...
  
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7. Figure 6: ¹H NMR in CDCl₃ at 298 K of: a) 1 (10 mM), b) 1:2 mixture of 1 and DIOFB, c) 1:2:1 mixture of 1, DI...
  
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Beilstein J. Org. Chem. 2019, 15, 947–954, doi:10.3762/bjoc.15.91

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Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

Rakesh Puttreddy,
Ngong Kodiah Beyeh,
S. Maryamdokht Taimoory,
Daniel Meister,
John F. Trant and
Kari Rissanen

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Published 10 Jul 2018

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1. Graphical Abstract
2. Figure 1: The chemical structures of C-ethyl-2-bromoresorcinarene (BrC2), C-propyl-2-bromoresorcinarene (BrC3...
  
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3. Figure 2: X-ray crystal structures of (a) 3@BrC6, (b) 4@BrC6, (c) 5@BrC6, (d) 6@BrC6, (e) 7@BrC6, (f) 8@BrC6,...
  
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4. Figure 3: Comparison of X-ray crystal structures (a) 3@BrC2, (c) 3@BrC3, and (e) 3@BrC6 and their DFT-based o...
  
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5. Figure 4: (a) The negative potential localised on the N-oxide oxygen in 3@BrC6 and, (b) the positive charge d...
  
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6. Figure 5: An expansion of the ¹H NMR (6.6 mM at 298 K, 500 MHz) of BrC6 complexes with 3. Spectra are produce...
  
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Beilstein J. Org. Chem. 2018, 14, 1723–1733, doi:10.3762/bjoc.14.146

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A conformationally adaptive macrocycle: conformational complexity and host–guest chemistry of zorb[4]arene

Liu-Pan Yang,
Song-Bo Lu,
Arto Valkonen,
Fangfang Pan,
Kari Rissanen and
Wei Jiang

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Published 27 Jun 2018

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1. Graphical Abstract
2. Scheme 1: (a) Chemical structures of ZB4 and the guests involved in this research. The counterions are PF₆⁻. ...
  
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3. Figure 1: X-ray single crystal structure of ZB4 and the host–guest complexes. a) ZB4, b) 2⁺@ZB4-IV, c) 3⁺@ZB4...
  
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4. Figure 2: Parabolic free-energy relationship between log(K_R/K_H) and Hammett parameter σ_p. K_R: guests 11⁺–21⁺; ...
  
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5. Figure 3: X-ray single crystal structures of 14⁺@ZB4-III, 16⁺@ZB4-III, 18⁺@ZB4-III and 21⁺@ZB4-III. Butyl gro...
  
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6. Figure 4: X-ray single crystal structures of 18⁺@ZB4-III and 18⁺ in 18⁺@ZB4-III.
  
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7. Figure 5: Linear relationships of ΔH with temperature (left, slope = −0.13, R² = 0.9956) and TΔS (right, slop...
  
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Beilstein J. Org. Chem. 2018, 14, 1570–1577, doi:10.3762/bjoc.14.134

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Self-assembly of metallosupramolecular rhombi from chiral concave 9,9’-spirobifluorene-derived bis(pyridine) ligands

Rainer Hovorka,
Sophie Hytteballe,
Torsten Piehler,
Georg Meyer-Eppler,
Filip Topić,
Kari Rissanen,
Marianne Engeser and
Arne Lützen

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Published 18 Feb 2014

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1. Graphical Abstract
2. Scheme 1: Synthesis of ligands 3 and 6.
  
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3. Figure 1: ESI mass spectrum (positive mode) of an 1:1 mixture of (R)-3 and [(dppp)Pd(OTf)₂] in acetone.
  
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4. Figure 2: ¹H NMR spectra (500.1 MHz, in CD₂Cl₂/CD₃CN 3:1 at 298 K) of a) a 1:1 mixture of [Pd(dppp)]OTf₂ and (...
  
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5. Figure 3: ³¹P NMR spectra of a) a 1:1 mixture of [Pd(dppp)]OTf₂ and (R)-3, b) a 1:1 mixture of [Pd(dppp)]OTf₂...
  
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6. Figure 4: ESI mass spectrum (positive mode) of an 1:1:2 mixture of (R)-3, (S)-6, and [(dppp)Pt(OTf)₂] in acet...
  
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7. Figure 5: Single crystal X-ray structure analysis of [(dppp)₂Pd₂{(R)-3}₂][(dppp)₂Pd₂{(S)-3}₂](OTf)₈ obtained ...
  
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Beilstein J. Org. Chem. 2014, 10, 432–441, doi:10.3762/bjoc.10.40

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The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts

Kari Raatikainen,
Massimo Cametti and
Kari Rissanen

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Published 15 Jan 2010

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1. Graphical Abstract
2. Scheme 1: The chemical structures of the salts 1–13.
  
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3. Figure 1: X-ray structure of 4-IPhNH₃Cl (1) with numbering for selected atoms (a) and the packing scheme view...
  
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4. Figure 2: Interaction contacts in 4-IPhNH₃Cl (1; a), 4-BrPhNH₃Cl (2; b), 4-ClPhNH₃Cl (3; c) and 4-FPhNH₃Cl (4...
  
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5. Figure 3: X-ray structure of 4-IPhNH₃Br (5) with selected numbering scheme (a) and the packing scheme viewed ...
  
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6. Figure 4: X-ray structure of 4-IPhNH₃H₂PO₄ (6) with selected numbering scheme of the asymmetric unit and the ...
  
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7. Figure 5: X-ray structure of 3-IPyBnCl (9) with the selected numbering scheme of the asymmetric unit (a) and ...
  
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8. Figure 6: X-ray structure of 3-IPyHCl (10) with the selected numbering scheme of the asymmetric unit (a) and ...
  
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9. Figure 7: X-ray structure of 3-IPyH-5-NIPA (13) with selected numbering scheme of the asymmetric unit (a). A ...
  
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Beilstein J. Org. Chem. 2010, 6, No. 4, doi:10.3762/bjoc.6.4

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Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

Halogen bonding and host–guest chemistry between N-alkylammonium resorcinarene halides, diiodoperfluorobutane and neutral guests

Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

A conformationally adaptive macrocycle: conformational complexity and host–guest chemistry of zorb[4]arene

Self-assembly of metallosupramolecular rhombi from chiral concave 9,9’-spirobifluorene-derived bis(pyridine) ligands

The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts

Other Beilstein-Institut Open Science Activities

Keep Informed

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr4/PPh3 and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

Halogen bonding and host–guest chemistry between N-alkylammonium resorcinarene halides, diiodoperfluorobutane and neutral guests

Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

A conformationally adaptive macrocycle: conformational complexity and host–guest chemistry of zorb[4]arene

Self-assembly of metallosupramolecular rhombi from chiral concave 9,9’-spirobifluorene-derived bis(pyridine) ligands

The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts

Other Beilstein-Institut Open Science Activities

Keep Informed

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior