Reaction of diisobutylaluminium hydride with selenium and tellurium: new reagents for the synthesis of seleno- and telluro-amides

Abstract

Diisobutylaluminium hydride (Buⁱ₂AlH) undergoes reaction with elemental selenium and tellurium to afford new reagents having an Al–Se or an Al–Te bond. These directly convert amides to selenoamides and telluroformamides. This affords a one-pot route to selenoamides and telluroformamides starting from Se and Te, and may be suitable for large scale syntheses.

References

1. (a) For some recent reviews: A. Ogawa and N. Sonoda, in Comprehensive Organic Synthesis, ed. E. Winterfeldt, Pergamon, Oxford, UK, 1991, vol. 6, pp. 461–484; (b) C. P. Dell, in Comprehensive Organic Functional Group Transformations, ed. C. J. Moody, Pergamon, Oxford, UK, 1995, vol. 5, pp. 565–628.
2. (a) K. A. Lerstrup and L. Henriksen, J. Chem. Soc., Chem. Commun., 1979, 1102; (b) M. Segi, A. Kojima, T. Nakajima and S. Suga, Synlett, 1991, 2, 105; (c) G. M. Li, R. A. Zingaro, M. Segi, J. H. Reibenspies and T. Nakajima, Organometallics, 1997, 16, 756.
3. G. M. Li, J. H. Reibenspies and R. A. Zingaro, Heteroatom Chem., in the press.
4. (a) Some selected monographs and review articles: Selenium Reagents and Intermediates in Organic Synthesis, ed. J. E. Baldwin, Pergamon, Oxford, UK, 1986; (b) The Chemistry of Organic Selenium and Tellurium Compounds, ed. S. Patai and Z. Rappoport, Wiley, New York, 1986, vol. 1; (c) The Chemistry of Organic Selenium and Tellurium Compounds, ed. S. Patai, Wiley, New York, 1987, vol. 2; (d) K. J. Irgolic, in Houben-Weyl-Methoden der Organischen Chemie, ed. D. Klayman, 4th edn., Georg Thieme, Stuttgart, 1990, vol. E12b; (e) N. Petragnani, in Tellurium in Organic Synthesis, Academic Press, New York, 1994; (f) A. Krief, in Comprehensive Organometallic Chemistry II, ed. A. McKillop, Pergamon, Oxford, UK, 1995, vol. 11, ch. 13, pp. 515–569; (g) N. Petragnani, in ref. 4f, chapter 14, pp. 571–601; (h) F. S. Guziec, Jr., L. J. Guziec, in Comprehensive Organic Functional Group Transformations, ed. G. Pattenden, Pergamon, Oxford, UK, 1995, vol. 3, pp. 381–401.
5. (a) M. Segi, T. Koyama, Y. Takata, T. Nakajima and S. Suga, J. Am. Chem. Soc., 1989, 111, 8749; (b) M. Segi, T. Koyama, T. Nakajima, S. Suga, S. Murai and N. Sonoda, Tetrahedron Lett., 1989, 30, 2095; (c) G. M. Li, M. Segi and T. Nakajima, Tetrahedron Lett., 1992, 33, 3515; (d) M. Segi, T. Takahashi, H. Ichinose, G. M. Li and T. Nakajima, Tetrahedron Lett., 1992, 33, 7865; (e) G. M. Li, T. Kamogawa, M. Segi and T. Nakajima, Chem. Express, 1993, 8, 53.
6. A part of this work has been presented at the 7th International Conference on the Chemistry of Selenium and Tellurium (ICCST-7), July 1997, Vaalsbroek Castle, The Netherlands.
7. By reaction with less fresh Buⁱ₂AlH toluene solution, selenium gave a yellow solution and tellurium gave a brown-red suspension. It needed to reflux longer (3–4 h) to dissolve all selenium or tellurium powder, and the yields of by-product Buⁱ₂E₂(E: Se, Te) increased up to 20%.
8. As a controlled experiment, DIBAL-H (1.5 M solution in toluene) was heated at 120–130 °C for 2 h, but no gas was evolved and the NMR (¹H, ¹³C) measurement has proved that DIBAL-H is stable under these conditions.
9. In the ⁷⁷Se NMR spectra, (Me₂Al)₂Se resonated at δ–420 ppm under similar conditions (in [²H]₈toluene–THF solution), see: M. Segi and T. Nakajima, Yuki Gosei Kagaku Kyokai Shi, 1995, 53, 678.
10. (a) M. Lardon, J. Am. Chem. Soc., 1970, 92, 5063; (b) P. Granger, S. Chapelle, W. McWhinnie and A. Al-Rubaie, J. Organomet. Chem., 1981, 220, 149.
11. Using hexane to remove Buⁱ₂Se₂ or Buⁱ₂Te₂, and then CH₂Cl₂ to elute selenoamides or telluroamides. For compounds 3 and 13, acetone was used as the final solvent.