Author

20 article(s) from O'Hagan, David

Organo-fluorine chemistry V

David O’Hagan

Editorial
Published 17 Mar 2021

PDF

Beilstein J. Org. Chem. 2021, 17, 737–738, doi:10.3762/bjoc.17.63

Full Text

Synthesis of organic liquid crystals containing selectively fluorinated cyclopropanes

Zeguo Fang,
Nawaf Al-Maharik,
Peer Kirsch,
Matthias Bremer,
Alexandra M. Z. Slawin and
David O’Hagan

Full Research Paper
Published 14 Apr 2020

PDF
Album
1. Graphical Abstract
2. Figure 1: Examples of liquid crystal candidates with negative values for dielectric anisotropy (Δε) [6-10].
  
  Jump to Figure 1
3. Figure 2: Synthetic candidate LC targets 8–11.
  
  Jump to Figure 2
4. Scheme 1: Synthesis of 8. Reagents and conditions: a) TMSCF₃, NaI, THF, reflux, 55% [13,14].
  
  Jump to Scheme 1
5. Scheme 2: Synthesis of 9. Reagents and conditions: a) NBS, HF·Py, DCM; b) t-BuOK, DCM, 42% in two steps [15]; c) ...
  
  Jump to Scheme 2
6. Scheme 3: Synthesis of compound 10. Reagents and conditions: a) NaBH₄, MeOH, rt, 45%; b) C₄H₉OCH=CH₂, Pd(TFA)₂...
  
  Jump to Scheme 3
7. Scheme 4: Synthesis of compounds 11. Reagents and conditions: a) PPh₃CH₃Br, t-BuOK, diethyl ether, 0 °C to rt...
  
  Jump to Scheme 4
8. Figure 3: Theory study exploring the relative energies for different conformers of 11a.
  
  Jump to Figure 3
Supp. Info

Beilstein J. Org. Chem. 2020, 16, 674–680, doi:10.3762/bjoc.16.65

Full Text

Fluorine-containing substituents: metabolism of the α,α-difluoroethyl thioether motif

Andrea Rodil,
Alexandra M. Z. Slawin,
Nawaf Al-Maharik,
Ren Tomita and
David O’Hagan

Full Research Paper
Published 28 Jun 2019

PDF
Album
1. Graphical Abstract
2. Figure 1: Structures of trifluoromethyl sulfonyl ether bioactives.
  
  Jump to Figure 1
3. Figure 2: Comparison of log P values of comparative aryl thioether motifs [18].
  
  Jump to Figure 2
4. Figure 3: α,α-Difluoroethyl thioether substrates for metabolism studies.
  
  Jump to Figure 3
5. Scheme 1: Fluorometabolites 6–8 isolated after incubation of 4 with C. elegans. Ratios are the average of thr...
  
  Jump to Scheme 1
6. Scheme 2: Putative pathways for (α,α-difluoroethyl)(4-methoxyphenyl)sulfane (4) metabolism.
  
  Jump to Scheme 2
7. Scheme 3: C. elegans incubation of 5. Ratios are the average of three incubations.
  
  Jump to Scheme 3
8. Scheme 4: Incubation (four times) of oxygen ether 14 with C. elegans, gave 4-acetoxyphenol (15) as the major ...
  
  Jump to Scheme 4
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 1441–1447, doi:10.3762/bjoc.15.144

Full Text

Stereochemical outcomes of C–F activation reactions of benzyl fluoride

Neil S. Keddie,
Pier Alexandre Champagne,
Justine Desroches,
Jean-François Paquin and
David O'Hagan

Full Research Paper
Published 09 Jan 2018

PDF
Album
1. Graphical Abstract
2. Figure 1: C–F activation of benzylic fluorides to generate benzylamine or diarylmethane products.
  
  Jump to Figure 1
3. Figure 2: 7-[²H₁]-(R)-Benzyl fluoride ((R)-1).
  
  Jump to Figure 2
4. Scheme 1: Synthesis of enantioenriched 7-[²H₁]-(R)-benzyl fluoride ((R)-1) from benzaldehyde (2).
  
  Jump to Scheme 1
5. Figure 3: Partial ²H{¹H} NMR (107.5 MHz) with PBLG in CHCl₃ (13% w/w). (A) racemic sample of 6 (from Table 1, entry ...
  
  Jump to Figure 3
6. Scheme 2: Synthesis of enantioenriched (S)-diarylmethane 10 from diaryl ketone 11 and confirmation of configu...
  
  Jump to Scheme 2
7. Figure 4: Possible reactive intermediates for C–F activation of benzyl fluoride 1 with strong hydrogen bond d...
  
  Jump to Figure 4
Supp. Info

Beilstein J. Org. Chem. 2018, 14, 106–113, doi:10.3762/bjoc.14.6

Full Text

Fluorinated cyclohexanes: Synthesis of amine building blocks of the all-cis 2,3,5,6-tetrafluorocyclohexylamine motif

Tetiana Bykova,
Nawaf Al-Maharik,
Alexandra M. Z. Slawin and
David O'Hagan

Full Research Paper
Published 19 Apr 2017

PDF
Album
1. Graphical Abstract
2. Figure 1: The derivatives of all-cis-2,3,5,6-tetrafluorocyclohexane.
  
  Jump to Figure 1
3. Scheme 1: Reagents and conditions: a) Li (2.5 equiv), NH₃, t-BuOH (1 equiv), MeI (2 equiv), 3 h, −78 °C, 18 h...
  
  Jump to Scheme 1
4. Scheme 2: Reagents and conditions: a) Et₃N·3HF (8 equiv), 18 h, 140 °C; b) Tf₂O (4 equiv), pyridine, 1 h, 0 °...
  
  Jump to Scheme 2
5. Scheme 3: Reagents and conditions: a) Et₃N·3HF (8 equiv), 18 h, 140 °C; b) Tf₂O (4 equiv), pyridine, 1 h, 0 °...
  
  Jump to Scheme 3
6. Scheme 4: Reagents and conditions: a) terephthaloyl chloride (1 equiv), Et₃N (4 equiv), DMAP (20 mol %), DCM,...
  
  Jump to Scheme 4
7. Figure 2: X-ray structures and crystal packing of compounds 13, 14 and 15.
  
  Jump to Figure 2
Supp. Info

Beilstein J. Org. Chem. 2017, 13, 728–733, doi:10.3762/bjoc.13.72

Full Text

Organofluorine chemistry: Difluoromethylene motifs spaced 1,3 to each other imparts facial polarity to a cyclohexane ring

Mathew J. Jones,
Ricardo Callejo,
Alexandra M. Z. Slawin,
Michael Bühl and
David O'Hagan

Full Research Paper
Published 22 Dec 2016

PDF
Album
1. Graphical Abstract
2. Figure 1: Selected fluorinated polar alicyclic scaffolds.
  
  Jump to Figure 1
3. Scheme 1: Retrosynthetic plan to the preparation of 1,1,3,3-tetrafluorocyclohexane structures.
  
  Jump to Scheme 1
4. Scheme 2: Preparation of starting materials 5c and 6a–c.
  
  Jump to Scheme 2
5. Scheme 3: Deoxofluorination of diketones 5. Reagents and conditions: a) DAST, DCM, rt, overnight, 4a (traces)...
  
  Jump to Scheme 3
6. Scheme 4: Fluorodesulfurisation of bis-dithianes 6. Reagents and conditions: a) NIS, HF·Py, DCM, −78 °C to rt...
  
  Jump to Scheme 4
7. Figure 2: X-ray structure of compound 4c. The image shows two molecules stacked with the non-fluorine face po...
  
  Jump to Figure 2
8. Figure 3: ¹H NMR spectra of 4c. A) shows the spectrum in [²H₈]-toluene, and B) shows the spectrum in chlorofo...
  
  Jump to Figure 3
9. Figure 4: Electrostatic potential map for 4c calculated at the B3LYP/6-311G(d,p) level for an optimised struc...
  
  Jump to Figure 4
Supp. Info

Beilstein J. Org. Chem. 2016, 12, 2823–2827, doi:10.3762/bjoc.12.281

Full Text

Selectively fluorinated cyclohexane building blocks: Derivatives of carbonylated all-cis-3-phenyl-1,2,4,5-tetrafluorocyclohexane

Mohammed Salah Ayoup,
David B. Cordes,
Alexandra M. Z. Slawin and
David O'Hagan

Full Research Paper
Published 21 Dec 2015

PDF
Album
1. Graphical Abstract
2. Figure 1: All cis-hexafluoro- 1 and tetrafluorocyclohexanes 2 and 3 result in facially polarised ring motifs ...
  
  Jump to Figure 1
3. Scheme 1: Preparation of benzoic acids 11–13; i. HIO₄·2H₂O (50%), AcOH, H₂SO₄, I₂, H₂O, 70 °C 24 h, 92%.; ii....
  
  Jump to Scheme 1
4. Scheme 2: Synthesis of benzaldehyde derivatives 14 and 15: i. Pd(PPh₃)₄, Bu₃SnH, THF, CO (1 atm), 50 °C, 2–3 ...
  
  Jump to Scheme 2
5. Figure 2: X-ray structure of aldehyde 15. CCDC number 1432193.
  
  Jump to Figure 2
6. Scheme 3: Olefination reactions of 15 and the X-ray structure of 17 (CCDC number 1432194): i. Zn, TiCl₄, THF,...
  
  Jump to Scheme 3
7. Scheme 4: Reactions from aldehyde 15: i. NaBH₄, THF, 20 °C, 1 h, 98%.; ii. HI (57%), CHCl₃, 30 h, 95%; iii. Bu...
  
  Jump to Scheme 4
8. Scheme 5: Reactions of benzyl azide 21; i. 24, Cu(OAc)₂, Na ascorbate, t-BuOH, H₂O, 20 °C, 16 h, 72%; ii. HCl...
  
  Jump to Scheme 5
9. Scheme 6: Reactions of aldehyde 14: i. NaBH₄, THF, rt, 1 h, 98%.; ii. HI (57%), CHCl₃, 30 h, 94%; iii. Bu₄NN₃...
  
  Jump to Scheme 6
Supp. Info

Beilstein J. Org. Chem. 2015, 11, 2671–2676, doi:10.3762/bjoc.11.287

Full Text

Lewis acid-promoted hydrofluorination of alkynyl sulfides to generate α-fluorovinyl thioethers

Davide Bello and
David O'Hagan

Full Research Paper
Published 14 Oct 2015

PDF
Album
1. Graphical Abstract
2. Figure 1: Some spacial and electronic mimetics with fluorine as a design feature [3-6].
  
  Jump to Figure 1
3. Figure 2: α-Fluorovinyl thioesters offer prospects as thioester enol/ate mimetics [7].
  
  Jump to Figure 2
4. Scheme 1: HF·Py mediated hydrofluorinations of 1a.
  
  Jump to Scheme 1
5. Scheme 2: BF₃·Et₂O/3HF·Et₃N mediated hydrofluorination of 1a.
  
  Jump to Scheme 2
6. Scheme 3: Proposed Lewis acid-mediated hydroflurination of sulfides 1.
  
  Jump to Scheme 3
Supp. Info

Beilstein J. Org. Chem. 2015, 11, 1902–1909, doi:10.3762/bjoc.11.205

Full Text

Organic chemistry on surfaces: Direct cyclopropanation by dihalocarbene addition to vinyl terminated self-assembled monolayers (SAMs)

Malgorzata Adamkiewicz,
David O’Hagan and
Georg Hähner

Full Research Paper
Published 05 Dec 2014

PDF
Album
1. Graphical Abstract
2. Figure 1: General strategies for incorporating functional groups (FGs) on the surface of self-assembled monol...
  
  Jump to Figure 1
3. Figure 2: XPS scans after reactions with a) :CBr₂; b) :CCl₂ and c) :CF₂. In each case the upper traces are sc...
  
  Jump to Figure 2
4. Scheme 1: Model reactions of dec-1-ene (1) with dihalocarbenes in the liquid phase. a) and b) NaOH, BTEAC, CHX...
  
  Jump to Scheme 1
5. Figure 3: AFM images of 5 μm × 5 μm area of C₁₁-vinyl SAMs modified with a) :CBr₂ carbene, RMS 93 pm; b) :CCl₂...
  
  Jump to Figure 3
6. Figure 4: The experimental set-up for the dibromo-, dichloro- and difluorocarbene reactions performed on C₁₁-...
  
  Jump to Figure 4
Supp. Info

Beilstein J. Org. Chem. 2014, 10, 2897–2902, doi:10.3762/bjoc.10.307

Full Text

The difluoromethylene (CF₂) group in aliphatic chains: Synthesis and conformational preference of palmitic acids and nonadecane containing CF₂ groups

Yi Wang,
Ricardo Callejo,
Alexandra M. Z. Slawin and
David O’Hagan

Full Research Paper
Published 06 Jan 2014

PDF
Album
1. Graphical Abstract
2. Figure 1: The CF₂ group in 1c accelerates RCM reactions relative to CHF (1d) and CH₂ (1e) and with a similar ...
  
  Jump to Figure 1
3. Figure 2: X-ray structures of a) 1,1,4,4- (3) b) 1,1,7,7- (4) and c) 1,1,6,6- (5) tetrafluorocyclododecanes. ...
  
  Jump to Figure 2
4. Figure 3: Synthesis targets: Palmitic acid analogues 6a–c.
  
  Jump to Figure 3
5. Scheme 1: Synthesis route to 8,8-difluorohexadecanoic acid (6a).
  
  Jump to Scheme 1
6. Scheme 2: The synthesis of palmitic acid analogues 6b and 6c.
  
  Jump to Scheme 2
7. Figure 4: DSC traces for the three palmitic acid analogues 6a–c.
  
  Jump to Figure 4
8. Figure 5: The X-ray crystal structures of 8,8-difluorohexadecanoic acid (6a).
  
  Jump to Figure 5
9. Figure 6: The X-ray structure of 8,8,11,11-tetrafluorohexadecanoic acid (6c).
  
  Jump to Figure 6
10. Scheme 3: Synthesis route to the tetrafluorinated alkane 27.
  
  Jump to Scheme 3
11. Figure 7: The X-ray structure of 8,8,11,11-tetrafluorononadecane (27).
  
  Jump to Figure 7
12. Figure 8: Conformational interconversion of 1,4-di-CF₂ motif.
  
  Jump to Figure 8
Supp. Info

Beilstein J. Org. Chem. 2014, 10, 18–25, doi:10.3762/bjoc.10.4

Full Text

Organo-fluorine chemistry III

David O'Hagan

Editorial
Published 23 Oct 2013

PDF

Beilstein J. Org. Chem. 2013, 9, 2180–2181, doi:10.3762/bjoc.9.255

Full Text

The preferred conformation of erythro- and threo-1,2-difluorocyclododecanes

Yi Wang,
Peer Kirsch,
Tomas Lebl,
Alexandra M. Z. Slawin and
David O'Hagan

Full Research Paper
Published 10 Aug 2012

PDF
Album
1. Graphical Abstract
2. Figure 1: The Dunitz and Shearer structure of cyclododecane (1) [1,2]. There are four endo hydrogens above and fou...
  
  Jump to Figure 1
3. Figure 2: Crystal structures of (a) 1,1,4,4- (b) 1,1,7,7- and (c) 1,1,6,6-tetrafluorocyclododecanes (2–4) , i...
  
  Jump to Figure 2
4. Figure 3: Erythro- and threo-1,2-difluorocyclododecanes (5a and 5b).
  
  Jump to Figure 3
5. Scheme 1: Synthetic routes to erythro- (5a) and threo-1,2-difluorocyclododecane (5b).
  
  Jump to Scheme 1
6. Figure 4: X-ray crystal structure of threo-1,2-difluorocyclododecane (5b) showing corner angles and represent...
  
  Jump to Figure 4
7. Figure 5: Variable-temperature ¹⁹F{¹H} NMR of erythro- (5a) and threo-1,2-difluorocyclododecane (5b).
  
  Jump to Figure 5
8. Figure 6: Calculated relative energies of the conformations of the erythro (5a) and threo (5b) stereoisomers ...
  
  Jump to Figure 6
Supp. Info
Video

Beilstein J. Org. Chem. 2012, 8, 1271–1278, doi:10.3762/bjoc.8.143

Full Text

Single enantiomer synthesis of α-(trifluoromethyl)-β-lactam

Václav Jurčík,
Alexandra M. Z. Slawin and
David O'Hagan

Full Research Paper
Published 06 Jun 2011

PDF
Album
1. Graphical Abstract
2. Figure 1: Enantiomers of α-(trifluoromethyl)-β-lactam (1).
  
  Jump to Figure 1
3. Scheme 1: Synthetic route involving a diastereoisomeric separation to α-(trifluoromethyl)-β-lactam ((S)-1) fr...
  
  Jump to Scheme 1
4. Figure 2: X-ray structures of (a) β-lactam (S)-1 and (b) (αR,3R)-5c. (a) Determination of the absolute stereo...
  
  Jump to Figure 2
5. Scheme 2: Synthesis of stereoisomers 5c. The stereochemistry of the major isomer (αR,3R)-5c was solved by X-r...
  
  Jump to Scheme 2

Beilstein J. Org. Chem. 2011, 7, 759–766, doi:10.3762/bjoc.7.86

Full Text

Prins fluorination cyclisations: Preparation of 4-fluoro-pyran and -piperidine heterocycles

Guillaume G. Launay,
Alexandra M. Z. Slawin and
David O'Hagan

Full Research Paper
Published 26 Apr 2010

PDF
Album
1. Graphical Abstract
2. Scheme 1: The C–F bond forming Prins reaction leading to 4-fluoropyrans [10].
  
  Jump to Scheme 1
3. Figure 1: X-ray crystal structure of syn-5a.
  
  Jump to Figure 1
4. Scheme 2: Ring opening hydrogenation of an oxa-Prins product.
  
  Jump to Scheme 2
5. Figure 2: X-ray crystal structure of the major bicyclic tetrahydropyran diastereoisomer 9b.
  
  Jump to Figure 2
6. Scheme 3: Reaction using (E)-11a and (Z)-11b hex-3-en-1-ols with 4-nitrobenzaldehyde to generate 4-fluorotetr...
  
  Jump to Scheme 3
7. Figure 3: X-ray crystal structure of the minor anti-piperidine product 14d.
  
  Jump to Figure 3
Supp. Info

Beilstein J. Org. Chem. 2010, 6, No. 41, doi:10.3762/bjoc.6.41

Full Text

Organo-fluorine chemistry II

David O'Hagan

Editorial
Published 20 Apr 2010

PDF

Beilstein J. Org. Chem. 2010, 6, No. 36, doi:10.3762/bjoc.6.36

Full Text

Three step synthesis of single diastereoisomers of the vicinal trifluoro motif

Vincent A. Brunet,
Alexandra M. Z. Slawin and
David O'Hagan

Full Research Paper
Published 05 Nov 2009

PDF
Album
1. Graphical Abstract
2. Scheme 1: Previous six step route to the vicinal all-syn-trifluoro motif.
  
  Jump to Scheme 1
3. Scheme 2: Novel three step successive fluorination strategy from α,β-epoxy alcohols to different diastereoiso...
  
  Jump to Scheme 2
4. Scheme 3: Synthesis approach to the requisite α,β-epoxy alcohols 6b and 7b.
  
  Jump to Scheme 3
5. Figure 1: X-ray structure (CCDC 750307) and stereochemistry of α,β-epoxy alcohol 7b.
  
  Jump to Figure 1
6. Figure 2: X-ray structure (CCDC 750306) and stereochemistry of α,β-epoxy alcohol 7a.
  
  Jump to Figure 2
7. Scheme 4: Three step sequential fluorination from α,β-epoxy alcohols to eg. the vicinyltrifluoro tosylate 11.
  
  Jump to Scheme 4
8. Scheme 5: Unexpected cyclisation of 9b to furan 14 with HF·pyridine. An X-ray structure of 14 (CCDC 750309) r...
  
  Jump to Scheme 5
9. Scheme 6: Epoxide ring opening of 9b with 3HF·Et₃N required forcing conditions. The structure and stereochemi...
  
  Jump to Scheme 6
10. Scheme 7: Three step sequential fluorination from α,β-epoxy alcohol 7b to vicinal trifluoro tosylate 17b.
  
  Jump to Scheme 7
11. Scheme 8: Epoxide ring opening with 3HF∙Et₃N and synthesis of the all-syn vicinal trifluoro tosylate 17a.
  
  Jump to Scheme 8
Supp. Info

Beilstein J. Org. Chem. 2009, 5, No. 61, doi:10.3762/bjoc.5.61

Full Text

Synthesis of phosphonate and phostone analogues of ribose-1-phosphates

Pitak Nasomjai,
David O'Hagan and
Alexandra M. Z. Slawin

Full Research Paper
Published 27 Jul 2009

PDF
Album
1. Graphical Abstract
2. Scheme 1: Biosynthetic pathway from fluoride ion to fluoroacetate 1 and 4-fluorothreonine 2 in S. cattleya [2].
  
  Jump to Scheme 1
3. Figure 1: Synthesized phosphonates 8 and 9 and cyclic phostones 10 and 11.
  
  Jump to Figure 1
4. Scheme 2: Synthetic route A. Reagents and conditions: a) acetone, concd H₂SO₄ (cat.), 6 h, 86%; b) Deoxo-fluo...
  
  Jump to Scheme 2
5. Scheme 3: Synthetic route B. Reagents and conditions: a) acetone, concd H₂SO₄ (cat.), 4 h, 90%; b) TrCl, pyri...
  
  Jump to Scheme 3
6. Figure 2: X-Ray crystal structure of cyclohexylammonium salt 8a.
  
  Jump to Figure 2
Supp. Info

Beilstein J. Org. Chem. 2009, 5, No. 37, doi:10.3762/bjoc.5.37

Full Text

Themed series in organo- fluorine chemistry

David O'Hagan

Editorial
Published 25 Apr 2008

PDF

Beilstein J. Org. Chem. 2008, 4, No. 11, doi:10.3762/bjoc.4.11

Full Text

The vicinal difluoro motif: The synthesis and conformation of erythro- and threo- diastereoisomers of 1,2-difluorodiphenylethanes, 2,3-difluorosuccinic acids and their derivatives

David O'Hagan,
Henry S. Rzepa,
Martin Schüler and
Alexandra M. Z. Slawin

Full Research Paper
Published 02 Oct 2006

PDF
Album
1. Graphical Abstract
2. Scheme 1: Synthesis of vicinal dimethyl difluorosuccinates. The conversion of the tartrates 1 with SF₄ and HF ...
  
  Jump to Scheme 1
3. Scheme 2: Schlosser's route to vicinal erythro- or threo- difluoro alkanes 5 [13].
  
  Jump to Scheme 2
4. Scheme 3: Halofluorination of electron-rich alkenes with in situ fluoride displacement generates vicinal difl...
  
  Jump to Scheme 3
5. Scheme 4: Bromofluorination of stilbene [19].
  
  Jump to Scheme 4
6. Scheme 5: Treatment of anti-14 with base generated the E-fluorostilbene 15 by an anti elimination mechanism.
  
  Jump to Scheme 5
7. Scheme 6: Hypothesis for the predominent retention of configuration during fluoride substitution via phenoniu...
  
  Jump to Scheme 6
8. Scheme 7: Proposed C-C bond rotation during the preparation of 14 from cis-stilbene.
  
  Jump to Scheme 7
9. Figure 1: Crystal structure of erythro-13.
  
  Jump to Figure 1
10. Figure 2: X-ray structure of threo-13.
  
  Jump to Figure 2
11. Figure 3: Expanded regions of the second order AA'XX' spin systems in the ¹H-NMR (left) and ¹⁹F-NMR spectra (...
  
  Jump to Figure 3
12. Figure 4: NMR coupling constants and calculated relative energies (kcalmol^-1) of the staggered conformers of ...
  
  Jump to Figure 4
13. Scheme 8: Synthesis of erythro-19 via ozonolysis of erythro-13.
  
  Jump to Scheme 8
14. Figure 5: X-ray structure of erythro-19.
  
  Jump to Figure 5
15. Figure 6: X-ray structure of threo-19.
  
  Jump to Figure 6
16. Scheme 9: Strategy for the preparation of diastereoisomers of erythro- and threo- 20.
  
  Jump to Scheme 9
17. Figure 7: NMR (CDCl₃, RT) coupling constants of erythro- and threo- 2,3-difluoro-3-phenylpropionates 21.
  
  Jump to Figure 7
18. Figure 8: Newman projections showing the staggered conformations of erythro- and threo- 21.
  
  Jump to Figure 8
19. Figure 9: X-ray structure of methyl threo- 21.
  
  Jump to Figure 9
20. Figure 10: The preferred conformation of α-fluoroamides has the C-F and amide carbonyl anti-planar [29,30].
  
  Jump to Figure 10
21. Scheme 10: The synthesis of stereoisomers of erythro- and threo- 22. These isomers could be separated by chrom...
  
  Jump to Scheme 10
22. Figure 11: X-ray structure of erythro-22.
  
  Jump to Figure 11
23. Figure 12: Crystal packing of erythro-22 clearly indicating intermolecular hydrogen bonding.
  
  Jump to Figure 12
24. Figure 13: X-ray structure of threo-22.
  
  Jump to Figure 13
25. Figure 14: The conformations of erythro- and threo- 23 are very different as a consequence of each conformatio...
  
  Jump to Figure 14
26. Figure 15: ³J_HF and ³J_HH coupling constants for the erythro (yellow) and threo (blue) diastereoisomers of the ...
  
  Jump to Figure 15
27. Figure 16: Newman projections of the three staggered conformations of the erythro and threo stereoisomers of t...
  
  Jump to Figure 16
28. Figure 17: The average coupling constant with no conformational bias. The limiting coupling constants J_g = 8 H...
  
  Jump to Figure 17
29. Figure 18: The observed ³J_HF coupling constants are an average over the rotational isomers.
  
  Jump to Figure 18
Supp. Info

Beilstein J. Org. Chem. 2006, 2, No. 19, doi:10.1186/1860-5397-2-19

Full Text

Stereoselective α-fluoroamide and α-fluoro- γ-lactone synthesis by an asymmetric zwitterionic aza-Claisen rearrangement

Kenny Tenza,
Julian S. Northen,
David O'Hagan and
Alexandra M. Z. Slawin

Full Research Paper
Published 17 Oct 2005

PDF
Album
1. Graphical Abstract
2. Scheme 1: Reagents: i N₃CH₂C(O)F, AlMe₃
  
  Jump to Scheme 1
3. Scheme 2: Reagents: i KF, DMF, 73%; ii NaOH, EtOH then aqHCl, 44%; iii (CO)₂Cl₂, 90%.
  
  Jump to Scheme 2
4. Scheme 3: Reagents: i iPr₂EtN, Yb(OTf)₃, 9, DCM, 92%; ii I₂, THF/ H₂O, Na₂S₂O₃, 82%.
  
  Jump to Scheme 3
5. Scheme 4: Reagents i. I₂, THF/H₂O.
  
  Jump to Scheme 4
6. Scheme 5: Reagents: (a) I₂, THF/H₂O, Na₂S₂O₃.
  
  Jump to Scheme 5
7. Scheme 6: Reagents: i iPr₂EtN, Yb(OTf)₃, 9 or PhCHFCOCl, DCM, 92%.
  
  Jump to Scheme 6
8. Scheme 7: Reagents: i. LiAlH₄, THF, 99%; ii. HCl-Et₂O.
  
  Jump to Scheme 7
9. Figure 1: ORTEP drawing of (2S, 2'S)-28 showing two crystallographically independent molecules within the uni...
  
  Jump to Figure 1
10. Scheme 8: Reagents: (a) I₂, THF/H₂O, Na₂S₂O₃.
  
  Jump to Scheme 8

Beilstein J. Org. Chem. 2005, 1, No. 13, doi:10.1186/1860-5397-1-13

Full Text

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