1. For reviews, see: (a) Drewes, S. E.; Roos, G. H. P. Tetrahedron 1988, 44, 4653–4670.
2. (b) Basavaiah, D.; Rao, P. D.; Hyma, R. S. Tetrahedron 1996, 52, 8001–8062.
3. (c) Ciganek, E. Org. React. 1997, 51, 201–350.
4. Bode, M. L.; Kaye, P. T. Tetrahedron Lett. 1991, 32, 5611–5614.
5. Recently, Kawanisi et al., Aggarwal et al., Kataoka et al., and Kobayashi et al. reported the Lewis acid-accelerated Baylis–Hillman reaction. (a) (Et3Al+Bu3P, CH2Cl2, 80°C) Imagawa, T.; Uemura, K.; Nagai, Z.; Kawanisi, M. Syn. Commun. 1984, 14, 1267–1273. (b) (La(OTf)3+(R)-BINOL (or other alcoholic ligands)+DABCO, MeCN, 25°C) Aggarwal, V. K.; Tarver, G. J.; McCague, R. Chem. Commun. 1996, 2713–2714. (c) (TiCl4+Me2S (or other chalcogens), CH2Cl2, rt) Kataoka, T.; Iwama, T.; Tsujiyama, S. Chem. Commun. 1998, 197–198. (d) (LiClO4+DABCO, Et2O, −25°C–rt) Kawamura, M.; Kobayashi, S. Tetrahedron Lett. 1999, 40, 1539–1542.