Highly efficient deprotection of acetals by titanium cation-exchanged montmorillonite as a strong solid acid catalyst

Chemistry Letters

Volumn 32, Issue 7, 2003, Pages 648-649

  Kawabata, Tomonori ^a   Kato, Masaki ^a   Mizugaki, Tomoo ^a   Ebitani, Kohki ^a   Kaneda, Kiyotomi ^a  

^a OSAKA UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ACETAL DERIVATIVE; MONTMORILLONITE; TITANIUM;

ARTICLE; CATALYSIS; CHEMICAL STRUCTURE; DEPROTECTION REACTION; PROTON NUCLEAR MAGNETIC RESONANCE; SOLID; SYNTHESIS;

EID: 0141428971     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.2003.648     Document Type: Article

References (20)

1. T. W. Greene and P. G. Wuts, "Protecting Groups in Organic Synthesis," 2nd ed., Wiley & Sons, New York (1991) and references cited therein.
2. 2O: d) M. H. Habibi, S. Tangestaninejad, I. M. Baltork, V. Mirkhani, and B. Yadollahi, Tetrahedron Lett., 42, 6771 (2001).
3. 2O: d) M. H. Habibi, S. Tangestaninejad, I. M. Baltork, V. Mirkhani, and B. Yadollahi, Tetrahedron Lett., 42, 6771 (2001).
4. 2O: d) M. H. Habibi, S. Tangestaninejad, I. M. Baltork, V. Mirkhani, and B. Yadollahi, Tetrahedron Lett., 42, 6771 (2001).
5. 2O: d) M. H. Habibi, S. Tangestaninejad, I. M. Baltork, V. Mirkhani, and B. Yadollahi, Tetrahedron Lett., 42, 6771 (2001).
6. 2: b) K. S. Kim, Y. H. Song, B. H. Lee, and C. S. Hahn, J. Org. Chem., 51, 404 (1986).
7. 2: b) K. S. Kim, Y. H. Song, B. H. Lee, and C. S. Hahn, J. Org. Chem., 51, 404 (1986).
8. For excellent reviews of mont-catalyzed organic syntheses, see: a) P. Laszlo, Acc. Chem. Res., 19, 121 (1986). b) Y. Izumi and M. Onaka, Adv. Catal., 38, 245 (1992).
9. For excellent reviews of mont-catalyzed organic syntheses, see: a) P. Laszlo, Acc. Chem. Res., 19, 121 (1986). b) Y. Izumi and M. Onaka, Adv. Catal., 38, 245 (1992).
10. a) K. Ebitani, T. Kawabata, K. Nagashima, T. Mizugaki, and K. Kaneda, Green. Chem., 2, 157 (2000).
11. b) T. Kawabata, T. Mizugaki, K. Ebitani, and K. Kaneda, Tetrahedron Lett., 42, 8329 (2001).
12. 4 and the crude product was recrystallized from pet ether to afford pure benzophenone (0.53 g, 98%).
13. For the deprotection of acetals by montmorillonite K10, see: a) E. C. L. Gautier, A. E. Graham, A. McKillop, S. P. Standen, and R. J. K. Taylor, Tetrahedron Lett., 38, 1881 (1997). b) T.-S. Li and S.-H. Li, Synth. Commun., 27, 2299 (1997). c) J.-I. Asakura, M. J. Robins, Y. Asaka, and T. H. Kim, J. Org. Chem., 61, 9026 (1996).
14. For the deprotection of acetals by montmorillonite K10, see: a) E. C. L. Gautier, A. E. Graham, A. McKillop, S. P. Standen, and R. J. K. Taylor, Tetrahedron Lett., 38, 1881 (1997). b) T.-S. Li and S.-H. Li, Synth. Commun., 27, 2299 (1997). c) J.-I. Asakura, M. J. Robins, Y. Asaka, and T. H. Kim, J. Org. Chem., 61, 9026 (1996).
15. For the deprotection of acetals by montmorillonite K10, see: a) E. C. L. Gautier, A. E. Graham, A. McKillop, S. P. Standen, and R. J. K. Taylor, Tetrahedron Lett., 38, 1881 (1997). b) T.-S. Li and S.-H. Li, Synth. Commun., 27, 2299 (1997). c) J.-I. Asakura, M. J. Robins, Y. Asaka, and T. H. Kim, J. Org. Chem., 61, 9026 (1996).
16. For recent reports on heterogeneous reactions using zeolite beta as an acid catalyst, see, nitration: a) K. Smith, A. Musson, and G. A. DeBoos, J. Org. Chem., 63, 8448 (1998). acylation: b) P. Andy, J. Garcia-Martinez, G. Lee, H. Gonzalez, C. W. Jones, and M. E. Davis, J. Catal., 192, 215 (2000). Note that these systems are limited to the reactions of small substrates.
17. For recent reports on heterogeneous reactions using zeolite beta as an acid catalyst, see, nitration: a) K. Smith, A. Musson, and G. A. DeBoos, J. Org. Chem., 63, 8448 (1998). acylation: b) P. Andy, J. Garcia-Martinez, G. Lee, H. Gonzalez, C. W. Jones, and M. E. Davis, J. Catal., 192, 215 (2000). Note that these systems are limited to the reactions of small substrates.
18. M. Hino, S. Kobayashi, and K. Arata, J. Am. Chem. Soc., 110, 6439 (1979).
19. Y. Lvov, K. Ariga, I. Ichinose, and T. Kunitake, Langmuir, 12, 3038 (1996).
20. 3CN, THF, or toluene resulted in lower yields of benzophenone (26-29%); correspondingly, the interlayer spaces using these solvents were less than 10 Å.