Use of scandium tris(trifluoromethanesulfonate) as a Lewis acid catalyst in supercritical carbon dioxide: Efficient Diels-Alder reactions and pressure dependent enhancement of endo:exo stereoselectivity

Chemical Communications

Volumn , Issue 16, 1999, Pages 1459-1460

  Oakes, R Scott ^a   Heppenstall, Toby J ^a   Shezad, Najam ^a   Clifford, Anthony A ^a   Rayner, Christopher M ^a  

^a UNIVERSITY OF LEEDS   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ACRYLIC ACID DERIVATIVE; CARBON DIOXIDE; CYCLOPENTADIENE DERIVATIVE; ORGANIC SOLVENT; SCANDIUM;

ARTICLE; CATALYST; CHEMICAL REACTION; PRESSURE; STEREOCHEMISTRY;

EID: 0033592174     PISSN: 13597345     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (14)

1. A. A. Clifford, Fundamentals of Supercritical Fluids, Oxford University Press, 1998; A. A. Clifford, in Supercritical Fluids, ed. E. Kiran and J. M. H. Levelt Sengers, Kluwer, 1994, 449; see also ref. 3 and 4 and references cited therein.
2. A. A. Clifford, Fundamentals of Supercritical Fluids, Oxford University Press, 1998; A. A. Clifford, in Supercritical Fluids, ed. E. Kiran and J. M. H. Levelt Sengers, Kluwer, 1994, 449; see also ref. 3 and 4 and references cited therein.
3. See for example: L. E. McMahon, P. Timmins, A. C. Williams and P. York, J. Pharm. Sci., 1996, 85, 1064; J. W. Tom, G. B. Lim, P. G. Debendetti and R. K. Prud'homme, in Supercritical Fluid Engineering Science - Fundamentals and Applications, ed. E. Kiran and J. F. Brennecke, ACS Symposium Series 514, 1993, ch. 11; P. G. Debendetti, Supercritical Fluids, ed. E. Kiran and J. M. H. Levelt Sengers, Kluwer, 1994, 719.
4. See for example: L. E. McMahon, P. Timmins, A. C. Williams and P. York, J. Pharm. Sci., 1996, 85, 1064; J. W. Tom, G. B. Lim, P. G. Debendetti and R. K. Prud'homme, in Supercritical Fluid Engineering Science - Fundamentals and Applications, ed. E. Kiran and J. F. Brennecke, ACS Symposium Series 514, 1993, ch. 11; P. G. Debendetti, Supercritical Fluids, ed. E. Kiran and J. M. H. Levelt Sengers, Kluwer, 1994, 719.
5. See for example: L. E. McMahon, P. Timmins, A. C. Williams and P. York, J. Pharm. Sci., 1996, 85, 1064; J. W. Tom, G. B. Lim, P. G. Debendetti and R. K. Prud'homme, in Supercritical Fluid Engineering Science - Fundamentals and Applications, ed. E. Kiran and J. F. Brennecke, ACS Symposium Series 514, 1993, ch. 11; P. G. Debendetti, Supercritical Fluids, ed. E. Kiran and J. M. H. Levelt Sengers, Kluwer, 1994, 719.
6. R. S. Oakes, A. A. Clifford, K. D. Bartle, M. Thornton-Pett and C. M. Rayner, Chem. Commun., 1999, 247.
7. A. A. Clifford, K. Pople, W. J. Gaskill, K. D. Bartle and C. M. Rayner, J. Chem. Soc., Faraday Trans., 1998, 94, 1451.
8. For a recent review see: C. P. Dell, J. Chem. Soc., Perkin Trans. 1, 1998, 3873.
9. See ref. 1 and references cited therein. Protic acid catalysed process have been reported including our own work on sulfur oxidation (ref. 3), see also: M. G. Hitzler, F. R. Smail, S. K. Ross and M. Poliakoff, Chem. Commun., 1998, 359.
10. N. Shezad, R. S. Oakes, A. A. Clifford and C. M. Rayner, Tetrahedron Lett., 1999, 40, 2221.
11. For a recent review see: S. Kobayashi, Eur. J. Chem., 1999, 15.
12. 1H NMR. Conversions were typically > 90%, and isolated yields > 80%. Density calibration was achieved by metering known amounts of carbon dioxide into the reaction vessel under standard reaction conditions (including reagents) using an ISCO 100D programmable syringe pump. Knowing the amount of carbon dioxide, the reactor volume and by observing the pressure, a calibration curve can be plotted for density versus pressure at constant temperature.
13. See for example: D. Andrew, B. T. Des Islet, A. Margaritis and A. C. Weedon, J. Am. Chem. Soc., 1995, 117, 6132; Y. Ikushima, N. Saito and M. Arai, J. Phys. Chem., 1992, 96, 2293.
14. See for example: D. Andrew, B. T. Des Islet, A. Margaritis and A. C. Weedon, J. Am. Chem. Soc., 1995, 117, 6132; Y. Ikushima, N. Saito and M. Arai, J. Phys. Chem., 1992, 96, 2293.