1. For a review, see: Chelucci, G. Gazz. Chim. Ital., 1992, 122, 89. Brunner, H.; Störiko, R.; Nuber, B. Tetrahedron: Asymmetry, 1998, 9, 407. Nordström, K.; Macedo, E.; Moberg, C. J. Org. Chem., 1997, 62, 1604. Davies. I. W.; Gerena, L.; Cai, D.; Larsen, R. D.; Verhoeven, T. R.; Reider, P. J. Tetrahedron Lett., 1997, 38, 1145. Angell, R. M.; Barrett, A. G.; Braddock, D. C.; Swallow, S.; Vickery, B. D. J. Chem. Soc., Chem. Commun., 1997, 919. Davies, D.; Fawcett, J.; Garratt, S. A.; Russell, D. R. Chem. Commun., 1997, 1351. Brunel, J. M.; Constantieux, T.; Labade, A.; Lubatti, F.; Buono, G. Tetrahedron Lett., 1997, 5971. Duboc-Toia, C.; Menage, S.; Lambeaux, C.; Fontecave, M. Tetrahedron Lett., 1997, 3727. Iovel, I.; Popelis, Y.; Fleisher, M.; Lukevics, E. Tetrahedron: Asymmetry, 1997, 8, 1279. Yao, S.; Johannesen, M.; Jorgensen, K. A. J. Chem. Soc., Perkin Trans. 1, 1997, 2345. Zhang, H.; Xue, F.; Mak, T. C. W.; Chan, K. S. J. Org. Chem., 1996, 8002. Datta Gupta, A.; Singh, V. Tetrahedron Lett., 1996, 37, 2633. See also Refs. 2–7.
2. (a) Chelucci, G.; Cabras, M. A. Tetrahedron: Asymmetry, 1996, 7, 965.
3. (b) Chelucci, G.; Berta, D.; Saba, A. Tetrahedron, 1997, 53, 3843. Vries, A. H. M.; Hof, R. P.; Staal, D.; Kellogg, R. M.; Feringa, B. Tetrahedron: Asymmetry, 1997, 8, 1539.
4. For an example of chiral pyridine-thiols, see: Koning, B.; Hulst, R.; Bouter, A.; Meetsma, A.; Kellogg, R. M. Chem. Commun., 1997, 1065
5. Chelucci, G.; Pinna, G. A.; Saba, A. Tetrahedron: Asymmetry, 1998, 9, 531. Chelucci, G.; Marchetti, M.; Sechi, B. J. Mol. Catal., 1997, 122, 111. Chelucci, G.; Medici, S.; Saba, A. Tetrahedron: Asymmetry, 1997, 8, 3183. Chelucci, G. Tetrahedron: Asymmetry, 1997, 8, 2667.