Titanocene(II)-promoted reductive alkylation of anilides with thioacetals

Tetrahedron Letters

Volumn 46, Issue 18, 2005, Pages 3157-3160

  Takeda, Takeshi ^a   Yatsumonji, Yasutaka ^a   Tsubouchi, Akira ^a  

^a TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGY   (Japan)

Author keywords

Anilides; Anilines; Carbonyl olefination; Reduction; Thioacetals; Titanocene(II)

Indexed keywords

ACETAL DERIVATIVE; ALKYL GROUP; ANILIDE; TITANOCENE; WATER;

ALKYLATION; ARTICLE; MOLECULAR INTERACTION; OLEFINATION; REDUCTION; WITTIG REACTION;

EID: 17044385737     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2005.03.062     Document Type: Article

References (24)

1. Y. Horikawa, M. Watanabe, T. Fujiwara, and T. Takeda J. Am. Chem. Soc. 119 1997 1127
2. T. Takeda, M. Watanabe, N. Nozaki, and T. Fujiwara Chem. Lett. 1998 115
3. M.A. Rahim, H. Taguchi, M. Watanabe, T. Fujiwara, and T. Takeda Tetrahedron Lett. 39 1998 2153
4. T. Takeda, M. Watanabe, M.A. Rahim, and T. Fujiwara Tetrahedron Lett. 39 1998 3753
5. T. Fujiwara, N. Iwasaki, and T. Takeda Chem. Lett. 1998 741
6. M.A. Rahim, T. Fujiwara, and T. Takeda Tetrahedron 56 2000 763
7. T. Takeda, Y. Takagi, N. Saeki, and T. Fujiwara Tetrahedron Lett. 41 2000 8377
8. M.A. Rahim, H. Sasaki, J. Saito, T. Fujiwara, and T. Takeda Chem. Commun. 2001 625
9. T. Takeda, J. Saito, and A. Tsubouchi Tetrahedron Lett. 44 2003 5571
10. The treatment of enamine 6b with a mixture of titanocene(II) reagent 1 (2 equiv) and water (1 mL/1 mmol of 6b) at 25°C for 30 min produced the amine 10b in 61% yield. It is of interest that 10b was obtained in better yield (74%) when a THF solution of 1 was refluxed for 15 min before use. This fact implies that a certain low-valent titanium species other than the titanocene(II) species 1 also acts as a reducing agent in the one-pot reaction
11. For examples R.F. Borch, M.D. Bernstein, and H.D. Durst J. Am. Chem. Soc. 93 1971 2897
12. R.D. Bach, and D.K. Mitra J. Chem. Soc., Chem. Commun. 1971 1433
13. J.J. Barieux, and J. Gore Tetrahedron 28 1972 1537
14. T. Mitsudo, Y. Watanabe, M. Tanaka, S. Atsuta, K. Yamamoto, and Y. Takegami Bull. Chem. Soc. Jpn. 48 1975 1506
15. S. Kim, C.H. Oh, J.S. Ko, K.H. Ahn, and Y.J. Kim J. Org. Chem. 50 1985 1927
16. C.T. Goralski, B. Singaram, and H.C. Brown J. Org. Chem. 52 1987 4014
17. M. Periasamy, A. Devasagayaraj, N. Satyanarayana, and C. Narayana Synth. Commun. 19 1989 565
18. A.F. Abdel-Magid, K.G. Carson, B.D. Harris, C.A. Maryanoff, and R.D. Shah J. Org. Chem. 61 1996 3849
19. S.H. Pine, R.J. Pettit, G.D. Geib, S.G. Cruz, C.H. Gallego, T. Tijerina, and R.D. Pine J. Org. Chem. 50 1985 1212
20. L.F. Cannizzo, and R.H. Grubbs J. Org. Chem. 50 1985 2316
21. N.A. Petasis, and E.I. Bzowej J. Org. Chem. 57 1992 1327
22. N.A. Petasis, and S.-P. Lu Tetrahedron Lett. 36 1995 2393
23. K. Takai, O. Fujimura, Y. Kataoka, and K. Utimoto Tetrahedron Lett. 30 1989 211
24. 3 (0.46 mL, 2.7 mmol), at 25°C for 15 min, a THF (0.9 mL) solution of 2b (72 mg, 0.3 mmol) was added to the reaction mixture, which was stirred for 3 h at 30°C. After addition of water (0.3 mL), the mixture was further stirred for 30 min at 25°C. The usual work-up and purification by PTLC (silica gel, hexane-AcOEt = 95:5) gave 4b (88 mg, 66%)