Modified mesoporous silicate MCM-41 materials: Immobilised perruthenate - a new highly active heterogeneous oxidation catalyst for clean organic synthesis using molecular oxygen

Chemical Communications

Volumn , Issue 18, 1999, Pages 1907-1908

  Bleloch, Andrew ^a   Johnson, Brian F G ^b   Ley, Steven V ^b   Price, Adam J ^b   Shephard, Douglas S ^b   Thomas, Andrew W ^b  

^a UNIVERSITY OF CAMBRIDGE   (United Kingdom)

^b UNIVERSITY OF CAMBRIDGE   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ALCOHOL DERIVATIVE; CARBONYL DERIVATIVE; ORGANIC COMPOUND; OXYGEN; PERRUTHENATE; RUTHENIUM COMPLEX; SILICATE; UNCLASSIFIED DRUG;

ARTICLE; CATALYST; CHEMICAL REACTION; CHEMICAL STRUCTURE; OXIDATION;

EID: 0033592408     PISSN: 13597345     EISSN: None     Source Type: Journal    
DOI: 10.1039/a906354d     Document Type: Article

References (36)

1. R. Lenz and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1997, 3291.
2. I. E. Mark, P. R. Giles, M. Isukazaki, C. J. Urch and S. M. Brown, J. Am. Chem. Soc., 1997, 119, 12 661.
3. S. V. Ley, J. Norman, W. P. Griffith and S. P. Marsden, Synthesis, 1994, 640.
4. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1997, 1907; B. Hinzen, R. Lenz and S. V. Ley, Synthesis, 1998, 977.
5. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1997, 1907; B. Hinzen, R. Lenz and S. V. Ley, Synthesis, 1998, 977.
6. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
7. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
8. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
9. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
10. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
11. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
12. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
13. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
14. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
15. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
16. Several reviews considering various aspects of MCM-41 and other mesoporous materials have appeared: J. Y. Ying, C. P. Mehnert and M. S. Wong, Angew. Chem., Int Ed.., 1999, 38, 56; S. Biz and M. L. Occelli, Catal. Rev. Sci. Eng., 1998, 40, 329; K. Moller and T. Bein, Chem. Mater., 1998, 10, 2950; A. Corma, Top. Catal., 1997, 4, 249; G. D. Stucky, Q. Huo, A. Firouzi, B. F. Chmelka, S. Schacht, I. G. Voigt-Martin and F. Schuth, in Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, Vol 105, ed. H. Chon, S.-K. Ihm, Y. S. Uh, Elsevier, Amsterdam, 1997, 3; C. J. Brinker, Curr. Opin Solid State Mater. Sci., 1996, 1, 798; N. K. Raman, M. T. Anderson and C. J. Brinker, Chem. Mater., 1996, 8, 1682; D. M. Antonelli and J. Y. Ying, Curr. Opin. Colloid Interface Sci., 1996, 1, 523; P. Behrens, Angew. Chem., Int. Ed. Engl., 1996, 35, 515; X. S. Zhao, G. Q. Lu and G. J. Millar, Ind. Eng. Chem. Res., 1996, 35, 2075; A. Sayari, Chem. Mater., 1996, 8, 1840.
17. For different methods of tethering chiral catalysts, see D. E. De Vos, S. De Wildemann, B. F. Sels, P. J. Grobet and P. A. Jacobs, Angew. Chem., Int. Ed., 1999, 38, 980; B. F. G. Johnson, S. A. Raynor, D. S. Shephard, T. Maschmeyer, J. M. Thomas, G. Sankar, S. Bromley, R. D. Oldroyd, L. Gladden and M. D. Mantle, Chem. Commun., 1999, 1167.
18. For different methods of tethering chiral catalysts, see D. E. De Vos, S. De Wildemann, B. F. Sels, P. J. Grobet and P. A. Jacobs, Angew. Chem., Int. Ed., 1999, 38, 980; B. F. G. Johnson, S. A. Raynor, D. S. Shephard, T. Maschmeyer, J. M. Thomas, G. Sankar, S. Bromley, R. D. Oldroyd, L. Gladden and M. D. Mantle, Chem. Commun., 1999, 1167.
19. D. S. Shephard, W. Zhou, T. Maschmeyer, J. M. Matters, C. L. Roper, S. Parsons, B. F. G. Johnson and M. J. Duer, Angew. Chem., Int. Ed., 1998, 37, 2719; T. Maschmeyer, R. D. Oldroyd, G. Sankar, J. M. Thomas, I. J. Shannon, J. A. Klepetko, A. F. Masters, J. K. Beattie and C. R. A. Catlow, Angew. Chem., Int. Ed. Engl., 1997, 36, 1639; J. Liu, X. Feng, G. E. Fryxell, L.-Q. Wang, A. Y. Kim and M. Gong, Adv. Mater., 1998, 10, 161.
20. D. S. Shephard, W. Zhou, T. Maschmeyer, J. M. Matters, C. L. Roper, S. Parsons, B. F. G. Johnson and M. J. Duer, Angew. Chem., Int. Ed., 1998, 37, 2719; T. Maschmeyer, R. D. Oldroyd, G. Sankar, J. M. Thomas, I. J. Shannon, J. A. Klepetko, A. F. Masters, J. K. Beattie and C. R. A. Catlow, Angew. Chem., Int. Ed. Engl., 1997, 36, 1639; J. Liu, X. Feng, G. E. Fryxell, L.-Q. Wang, A. Y. Kim and M. Gong, Adv. Mater., 1998, 10, 161.
21. D. S. Shephard, W. Zhou, T. Maschmeyer, J. M. Matters, C. L. Roper, S. Parsons, B. F. G. Johnson and M. J. Duer, Angew. Chem., Int. Ed., 1998, 37, 2719; T. Maschmeyer, R. D. Oldroyd, G. Sankar, J. M. Thomas, I. J. Shannon, J. A. Klepetko, A. F. Masters, J. K. Beattie and C. R. A. Catlow, Angew. Chem., Int. Ed. Engl., 1997, 36, 1639; J. Liu, X. Feng, G. E. Fryxell, L.-Q. Wang, A. Y. Kim and M. Gong, Adv. Mater., 1998, 10, 161.
22. 10 wt% of the solid catalyst 3 corresponds to 0.3 wt% Ru by ICP analysis.
23. 10 wt% of the solid catalyst 6 corresponds to 1.1 wt% Ru by ICP analysis.
24. 3) was added MCMSP 6 (3.0 mg) and the resulting mixture heated at 80 °C, for 30 min to 3 h in an oxygen atmosphere. After cooling, filtration of the mixture followed by evaporation of the solution afforded the pure aldehyde in quantitative yield (Table 1). The solid catalytic oxidant reagent can be re-used many times (up to 12 times without loss of activity). It can be easily filtered through a polypropylene filter or through a bond elut cartridge and then washed off the surface with toluene. In addition, recovery by centrifugation was also found to be quantitative.
25. J. Habermann, S. V. Ley and J. S. Scott, J. Chem. Soc., Perkin Trans. 1, 1999, 1253.
26. D. S. Shephard, G. Sankar, J. M. Thomas, D. Ozkaya, B. F. G. Johnson, R. Raja, R. D. Oldroyd and R. G. Bell, Chem. Eur. J., 1998, 4, 1214.
27. 2. In experiments (i) and (iii), approximately 10 and 70% oxidation, respectively, to the aldehyde was observed after 3 days under the same conditions and complete leaching of potassium perruthenate was observed in both cases. The used solid material from experiments (ii) and (iii) showed no catalytic oxidative activity when reused.
28. D. G. Lee, Z. Wang and W. D. Chandler, J. Org. Chem., 1992, 57, 3276.
29. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 1; F. Haunert, M. H. Bolli, B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2235; S. V. Ley, M. H. Bolli, B. Hinzen, A.-G. Gervois and B. J. Hall, J. Chem. Soc., Perkin Trans. 1, 1998, 2239; M. H. Bolli and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2243; J. Habermann, S. V. Ley and J. S. Scott, J. Chem. Soc., Perkin Trans. 1, 1998, 3127; M. Caldarelli, J. Habermann and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1999, 107; S. V. Ley, A. W. Thomas and H. Finch, J. Chem. Soc., Perkin Trans. 1, 1999, 669; S. V. Ley, O. Schucht, A. W. Thomas and P. J. Murray, J. Chem. Soc., Perkin Trans. 1, 1999, 1251.
30. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 1; F. Haunert, M. H. Bolli, B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2235; S. V. Ley, M. H. Bolli, B. Hinzen, A.-G. Gervois and B. J. Hall, J. Chem. Soc., Perkin Trans. 1, 1998, 2239; M. H. Bolli and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2243; J. Habermann, S. V. Ley and J. S. Scott, J. Chem. Soc., Perkin Trans. 1, 1998, 3127; M. Caldarelli, J. Habermann and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1999, 107; S. V. Ley, A. W. Thomas and H. Finch, J. Chem. Soc., Perkin Trans. 1, 1999, 669; S. V. Ley, O. Schucht, A. W. Thomas and P. J. Murray, J. Chem. Soc., Perkin Trans. 1, 1999, 1251.
31. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 1; F. Haunert, M. H. Bolli, B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2235; S. V. Ley, M. H. Bolli, B. Hinzen, A.-G. Gervois and B. J. Hall, J. Chem. Soc., Perkin Trans. 1, 1998, 2239; M. H. Bolli and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2243; J. Habermann, S. V. Ley and J. S. Scott, J. Chem. Soc., Perkin Trans. 1, 1998, 3127; M. Caldarelli, J. Habermann and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1999, 107; S. V. Ley, A. W. Thomas and H. Finch, J. Chem. Soc., Perkin Trans. 1, 1999, 669; S. V. Ley, O. Schucht, A. W. Thomas and P. J. Murray, J. Chem. Soc., Perkin Trans. 1, 1999, 1251.
32. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 1; F. Haunert, M. H. Bolli, B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2235; S. V. Ley, M. H. Bolli, B. Hinzen, A.-G. Gervois and B. J. Hall, J. Chem. Soc., Perkin Trans. 1, 1998, 2239; M. H. Bolli and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2243; J. Habermann, S. V. Ley and J. S. Scott, J. Chem. Soc., Perkin Trans. 1, 1998, 3127; M. Caldarelli, J. Habermann and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1999, 107; S. V. Ley, A. W. Thomas and H. Finch, J. Chem. Soc., Perkin Trans. 1, 1999, 669; S. V. Ley, O. Schucht, A. W. Thomas and P. J. Murray, J. Chem. Soc., Perkin Trans. 1, 1999, 1251.
33. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 1; F. Haunert, M. H. Bolli, B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2235; S. V. Ley, M. H. Bolli, B. Hinzen, A.-G. Gervois and B. J. Hall, J. Chem. Soc., Perkin Trans. 1, 1998, 2239; M. H. Bolli and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2243; J. Habermann, S. V. Ley and J. S. Scott, J. Chem. Soc., Perkin Trans. 1, 1998, 3127; M. Caldarelli, J. Habermann and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1999, 107; S. V. Ley, A. W. Thomas and H. Finch, J. Chem. Soc., Perkin Trans. 1, 1999, 669; S. V. Ley, O. Schucht, A. W. Thomas and P. J. Murray, J. Chem. Soc., Perkin Trans. 1, 1999, 1251.
34. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 1; F. Haunert, M. H. Bolli, B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2235; S. V. Ley, M. H. Bolli, B. Hinzen, A.-G. Gervois and B. J. Hall, J. Chem. Soc., Perkin Trans. 1, 1998, 2239; M. H. Bolli and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2243; J. Habermann, S. V. Ley and J. S. Scott, J. Chem. Soc., Perkin Trans. 1, 1998, 3127; M. Caldarelli, J. Habermann and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1999, 107; S. V. Ley, A. W. Thomas and H. Finch, J. Chem. Soc., Perkin Trans. 1, 1999, 669; S. V. Ley, O. Schucht, A. W. Thomas and P. J. Murray, J. Chem. Soc., Perkin Trans. 1, 1999, 1251.
35. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 1; F. Haunert, M. H. Bolli, B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2235; S. V. Ley, M. H. Bolli, B. Hinzen, A.-G. Gervois and B. J. Hall, J. Chem. Soc., Perkin Trans. 1, 1998, 2239; M. H. Bolli and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2243; J. Habermann, S. V. Ley and J. S. Scott, J. Chem. Soc., Perkin Trans. 1, 1998, 3127; M. Caldarelli, J. Habermann and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1999, 107; S. V. Ley, A. W. Thomas and H. Finch, J. Chem. Soc., Perkin Trans. 1, 1999, 669; S. V. Ley, O. Schucht, A. W. Thomas and P. J. Murray, J. Chem. Soc., Perkin Trans. 1, 1999, 1251.
36. B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 1; F. Haunert, M. H. Bolli, B. Hinzen and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2235; S. V. Ley, M. H. Bolli, B. Hinzen, A.-G. Gervois and B. J. Hall, J. Chem. Soc., Perkin Trans. 1, 1998, 2239; M. H. Bolli and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1998, 2243; J. Habermann, S. V. Ley and J. S. Scott, J. Chem. Soc., Perkin Trans. 1, 1998, 3127; M. Caldarelli, J. Habermann and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1999, 107; S. V. Ley, A. W. Thomas and H. Finch, J. Chem. Soc., Perkin Trans. 1, 1999, 669; S. V. Ley, O. Schucht, A. W. Thomas and P. J. Murray, J. Chem. Soc., Perkin Trans. 1, 1999, 1251.