References
- Stork , G. and Dowd , S. R. 1963 . J. Am. Chem. Soc. , 85 : 2178 Knorr, R., Weiβ, A., Löw, P. and Räpple, E., Chem. Ber., 1980, 113,2462; for reviews in this area see, Pitacco, G. and Valentin, E., “Enamines and Ynamines”, in The Chemistry of Amino, Nitroso and Nitro Compounds and Their Derivatives, Vol. 1, ed. Patai, S., Wiley, Chichester (1982), pp. 623–714; Tennant, G., “Imines, Nitrones, Nitriles and Isocyanides” in, Comprehensive Organic Chemistry, Vol. 2, ed. Sutherland, I.O., series eds. Barton, W.H.R. and Ollis, W.D., Pergamon, Oxford (1979), pp 385–527
- Kauffmann , T. and Eidenschink , R. 1977 . Chem. Ber. , 110 : 645 and the reviews in Ref. 1.
- Colvin , E. W. and McGarry , D. G. 1985 . J. Chem. Soc., Chem. Commun. , : 539 Some selected examples are: Kerwin Jr., J.F., and Danishefsky, S., Tetrahedron Lett., 1982, 3739; Dubois, J.-E. and Axiotis, G., ibid., 1984: 214; Gennari, C., Venturini, I., Gislon, G. and Schimperna, G., ibid., 1987,227; Keck, G.E. and Enholm, E.J., J. Org. Chem., 1985,50,146; see also ref. 12 in Gennari, C., Columbo, L., Bertolini, G. and Schimperna, G., J. Org. Chem., 1987, 52,2754.
- Jahangir , MacLean , D. B. , Brook , M. A. and Holland , H. L. 1986 . J. Chem. Soc., Chem. Comm. , : 1608 idem, Can. J. Chem., in press; idem., Tetrahedron, in press.
- Clark , R. D. and Jahangir . J. Org. Chem. , in press. We thank the authors for providing a preprint of this manuscript
- Ha , D.-C. , Hart , D. J. and Yang , T.-K. 1984 . J. Am. Chem. Soc. , 106 : 4819 For related work with trimethylsilylimines, see and references cited therein; for recent related examples using TMSOTf as catalyst, see Pilli, R.A. and Russowsky, D., J. Chem. Soc., Chem. Commun., 1987,1053, Guanti, G., Narisano, E. and Banfi, L., Tetrahedron Lett., 1987,4331, 4335
- Typical Procedure: 1 mmol of the imine was dissolved in anhydrous Et2O or THF (2 mL) under an nitrogen atmosphere, cooled to 0°C, and trimethylsilyl triflate (1.1 mmol) was added, 1H-nmr indicated that iminium salt formation was complete after 20–30 min. The initially formed precipitate gradually dissolved over 20 min to leave an almost clear solution. The Grignard or alkyl lithium reagent (after cooling to -78°C) was added and the reaction stirred from 2–36 h (-78° or 0° - RT) and quenched with water or sat. NH4CI. Ether/water extraction, drying over anhyd. Na2SO4 and purification by flash chromatography was the usual work-up procedure. In some cases, better results were obtained with an acid/base extraction cycle and/or purification on neutral alumina
- Achiwa , K. , Sugiyama , K. and Sekiya , M. 1985 . Chem. Pharm. Bull. , 33 : 1975 and references cited therein; for a review of azomethine ylid 1,3-dipolar cycloadditions under acidic conditions see Vedejs, E. and West, F. G., Chem. Rev., 1986, 86, 941.