N–H activation vs. C–H activation: ruthenium-catalysed regioselective hydroamination of alkynes and hydroarylation of an alkene with N-methylaniline

Abstract

Phenylacetylene and its derivatives undergo regioselective insertion into the N–H bond of N-methylaniline in the presence of Ru₃(CO)₁₂ catalyst to afford N-methyl-N-(α-styryl)anilines in high yields, whereas styrene reacts with the ortho C–H bond of N-methylaniline giving 2-(1-phenylethyl)-N-methylaniline.

References

1. See for a review of intramolecular hydroamination, L. S. Hegedus, Angew. Chem., Int. Ed. Engl., 1988, 27, 1113.
2. See for reviews of intermolecular hydroamination: (a) T. E. Müller and M. Beller, Chem. Rev., 1998, 98, 675; (b) J.-J. Brunet, Gazz. Chim. Ital., 1997, 127, 111; (c) J.-J. Brunet, D. Neibecker and F. Niedercorn, J. Mol. Catal., 1989, 49, 235.
3. A. M. Baranger, P. J. Walsh and R. G. Bergman, J. Am. Chem. Soc., 1993, 115, 2753; Y. Li and T. J. Marks, Organometallics, 1996, 15, 3770; A. Haskel, T. Straub and M. S. Eisen, Organometallics, 1996, 15, 3773; M. S. Eisen, T. Straub and A. Haskel, J. Alloys Compd., 1998, 271–273, 116.
4. (a) A. L. Casalnuovo, J. C. Calabrese and D. Milstein, J. Am. Chem. Soc., 1988, 110, 6738; (b) P. J. Walsh, A. M. Baranger and R. G. Bergman, J. Am. Chem. Soc., 1992, 114, 1708; (c) A. L. Seligson and W. C. Trogler, Organometallics, 1993, 12, 744; (d) J.-J. Brunet, G. Commenges, D. Neibecker and K. Philippot, J. Organomet. Chem., 1994, 469, 221; (e) R. Dorta, P. Egli, F. Zürcher and A. Togni, J. Am. Chem. Soc., 1997, 119, 10857; (f) I. Nakamura, H. Itagaki and Y. Yamamoto, J. Org. Chem., 1998, 63, 6458 and references cited therein..
5. Rhodium-catalysed hydroamination of styrene and hex-1-ene has recently been reported as a side reaction of oxidative amination, see ref. 2(b)..
6. Mural et al. reported several examples of ruthenium-catalysed hydroarylation of alkenes and alkynes with aromatic ketones, imines, and esters: S. Murai, N. Chatani and F. Kakiuchi, Pure. Appl. Chem., 1997, 69, 589 and references cited therein..
7. (a) E. Sappa and L. Milone, J. Organomet. Chem., 1973, 61, 383; (b) G. C. Hsu, W. P. Kosar and W. D. Jones, Organometallics, 1994, 13, 385.
8. J. P. Collmann, L. S. Hegedus, J. R. Norton and R. G. Finke, Principles and Applications of Organotransition Metal Chemistry, University Science Books, Hill Valley, CA, 1987.
9. J. F. Hartwig, R. G. Bergman and R. A. Andersen, J. Am. Chem. Soc., 1991, 113, 3404.