Microwave-assisted in situ deprotection and ω-methoxylation of TMS-protected aryl alkynes

Tetrahedron Letters

Volumn 44, Issue 41, 2003, Pages 7611-7612

  Wettergren, Jenny ^a   Minidis, Alexander B E ^a  

^a ASTRAZENECA R AND D   (Sweden)

Author keywords

[No Author keywords available]

Indexed keywords

ALKYL GROUP; ALKYNE;

ARTICLE; CHEMICAL MODIFICATION; CHEMICAL REACTION; DEPROTECTION REACTION; GAS CHROMATOGRAPHY; HEATING; MICROWAVE RADIATION; NUCLEAR MAGNETIC RESONANCE; OMEGA METHOXYLATION; THIN LAYER CHROMATOGRAPHY;

EID: 0141852887     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2003.08.059     Document Type: Article

References (15)

1. For selected examples, see: (a) Reichert, J. S.; Bailey, J. H.; Nieuwland, J. A. J. Am. Chem. Soc. 1923, 45, 1552-1557; (b) Gillespie, J. F.; Price, C. C. J. Org. Chem. 1957, 22, 780-783; (c) Bardaji, M.; Laguna, A.; Jones, P. G. Organometallics 2001, 20, 3906-3912.
2. For selected examples, see: (a) Reichert, J. S.; Bailey, J. H.; Nieuwland, J. A. J. Am. Chem. Soc. 1923, 45, 1552-1557; (b) Gillespie, J. F.; Price, C. C. J. Org. Chem. 1957, 22, 780-783; (c) Bardaji, M.; Laguna, A.; Jones, P. G. Organometallics 2001, 20, 3906-3912.
3. For selected examples, see: (a) Reichert, J. S.; Bailey, J. H.; Nieuwland, J. A. J. Am. Chem. Soc. 1923, 45, 1552-1557; (b) Gillespie, J. F.; Price, C. C. J. Org. Chem. 1957, 22, 780-783; (c) Bardaji, M.; Laguna, A.; Jones, P. G. Organometallics 2001, 20, 3906-3912.
4. Samamoto T., Kondo Y., Shiraiwa M., Yamanaka H. Synthesis. 1984;245-247.
5. Sakamoto T., Kondo Y., Yamanaka H. Chem. Pharm. Bull. 33:1985;626-632.
6. Sakamoto T., Kondo Y., Yamanaka H. Chem. Pharm. Bull. 34:1986;2362-2368.
7. For a recent highlight see: Kuhnert N. Angew. Chem., Int. Ed. 41:2002;1863-1866.
8. Alternatively, CsOH and NaOH were employed since they have been reported elsewhere, see e.g. Ref. 2, or Tischler, A. N.; Lanza, T. J. Tetrahedron Lett. 1986, 27, 1653-1656 and Tzalis, D.; Koradin, C.; Knochel, P. Tetrahedron Lett. 1999, 40, 6193-6195.
9. Alternatively, CsOH and NaOH were employed since they have been reported elsewhere, see e.g. Ref. 2, or Tischler, A. N.; Lanza, T. J. Tetrahedron Lett. 1986, 27, 1653-1656 and Tzalis, D.; Koradin, C.; Knochel, P. Tetrahedron Lett. 1999, 40, 6193-6195.
10. Greene, T. W.; Wuts, P. G. M. In Protective Groups in Organic Chemistry, 3rd ed.; Wiley-Interscience: New York, 1999; Chapter 8, pp. 654-659.
11. See e.g.: (a) Sonogashira, K.; Tohda, Y.; Hagihara, N. Tetrahedron Lett. 1975, 16, 4467-4470; (b) Lee, J.-H.; Park, J.-S.; Cho, C.-G. Org. Lett. 2002, 4, 1171-1173.
12. See e.g.: (a) Sonogashira, K.; Tohda, Y.; Hagihara, N. Tetrahedron Lett. 1975, 16, 4467-4470; (b) Lee, J.-H.; Park, J.-S.; Cho, C.-G. Org. Lett. 2002, 4, 1171-1173.
13. 3/MeOH.
14. Higher temperatures can be achieved by the addition of a few drops of DMF. (Anders Franzén, Personal Chemistry, Sweden, personal communication). Under such conditions conversions slow down and the reactions proceed less cleanly.
15. Microwave reactions were run in 5 mL heavy-walled glass Smith process vials sealed with aluminum crimp caps fitted with a silicone septum. The oven was a Smith Synthesizer Single-mode microwave cavity producing continuous irraditation at 2450 MHz (Personal Chemistry AB, Uppsala, Sweden). General experimental procedure: 0.6 mmol of aryl (trimethylsilyl)ethyne and 6.0 mmol of potassium carbonate were mixed in 5 mL methanol in a 5 mL reaction tube and irradiated at 120 or 130°C for 15 min. Work-up was performed by adding ethyl acetate, followed by filtration and evaporation to dryness. NMR analysis of the crude product gave conversion ratios. Flash chromatography (heptane/ ethyl acetate) gave isolated products.