Use of N-Protected Amino Acids in the Minisci Radical Alkylation

Organic Letters

Volumn 5, Issue 23, 2003, Pages 4497-4499

  Cowden, Cameron J ^a  

^a MERCK RESEARCH LABORATORIES   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

AMINO ACID; GLYCINE; PHTHALIMIDE;

ALKYLATION; ARTICLE; CHEMICAL REACTION; DECARBOXYLATION; HIGH PERFORMANCE LIQUID CHROMATOGRAPHY; NUCLEAR MAGNETIC RESONANCE; OXIDATION; PROTECTION;

ALKYLATION; AMINO ACIDS;

EID: 0345359241     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol035814+     Document Type: Article

References (18)

1. Minisci, F.; Vismara, E.; Fontana, F. Heterocycles 1989, 28, 489. Minisci, F.; Recupero, F.; Punta, C.; Gambarotti, C.; Antonietti, F.; Fontana, F.; Pedulli, G. F. Chem. Commun. 2002, 2496 and references therein.
2. Minisci, F.; Vismara, E.; Fontana, F. Heterocycles 1989, 28, 489. Minisci, F.; Recupero, F.; Punta, C.; Gambarotti, C.; Antonietti, F.; Fontana, F.; Pedulli, G. F. Chem. Commun. 2002, 2496 and references therein.
3. Gardini, G. P.; Minisci, F.; Palla, G.; Arnone, A.; Galli, R. Tetrahedron Lett. 1971, 59.
4. Heinisch, G.; Jentzsch, A.; Kirchner, I. Tetrahedron Lett. 1978, 619.
5. Tada, M.; Furuse, R.; Kashima, H. Heterocycles 1992, 34, 357.
6. Minisci, F.; Citterio, A.; Giordano, C. Acc. Chem. Res. 1983, 16, 27.
7. Chao, W.; Weinreb, S. M. Tetrahedron Lett. 2000, 41, 9199. Renaud, P.; Seebach, D. Synthesis 1986, 424. For a review of 1-amidoalkyl radicals, see: Renaud, P.; Giraud, L. Synthesis 1996, 913.
8. Chao, W.; Weinreb, S. M. Tetrahedron Lett. 2000, 41, 9199. Renaud, P.; Seebach, D. Synthesis 1986, 424. For a review of 1-amidoalkyl radicals, see: Renaud, P.; Giraud, L. Synthesis 1996, 913.
9. Chao, W.; Weinreb, S. M. Tetrahedron Lett. 2000, 41, 9199. Renaud, P.; Seebach, D. Synthesis 1986, 424. For a review of 1-amidoalkyl radicals, see: Renaud, P.; Giraud, L. Synthesis 1996, 913.
10. Needles, H. L.; Whitfield, R. E. J. Org. Chem. 1964, 29, 3632.
11. Behrman, E. J.; Edwards, J. O. Rev. Inorg. Chem. 1980, 2, 179.
12. 4), and filtered through a glass fiber disk, and product 6a (8.32 g, 88%) was then isolated by crystallization from IPAc/hexanes.
13. Functionalized pyridazines have been used in the synthesis of trisubstituted 1,2,4-triazolo[4, 3-b]pyridazines, a heterocyclic system common to a number of subtype selective GABA-A agonists; see: Collins, I.; Castro, J. L.; Street, L. J. Tetrahedron Lett. 2000, 41, 781. Sparey, T. J.; Harrison, T. Tetrahedron Lett. 1998, 39, 5873. Chloropyridazines are also useful as interleukin-1β converting enzyme inhibitors, see: Dolle, R. E.; Hoyer, D.; Rinker, J. M.; Morgan, T.; Schmidt, S. J.; Helaszek, C. T.; Ator, M. A. Bioorg. Med. Chem. Lett. 1997, 7, 1003.
14. Functionalized pyridazines have been used in the synthesis of trisubstituted 1,2,4-triazolo[4, 3-b]pyridazines, a heterocyclic system common to a number of subtype selective GABA-A agonists; see: Collins, I.; Castro, J. L.; Street, L. J. Tetrahedron Lett. 2000, 41, 781. Sparey, T. J.; Harrison, T. Tetrahedron Lett. 1998, 39, 5873. Chloropyridazines are also useful as interleukin-1β converting enzyme inhibitors, see: Dolle, R. E.; Hoyer, D.; Rinker, J. M.; Morgan, T.; Schmidt, S. J.; Helaszek, C. T.; Ator, M. A. Bioorg. Med. Chem. Lett. 1997, 7, 1003.
15. Functionalized pyridazines have been used in the synthesis of trisubstituted 1,2,4-triazolo[4, 3-b]pyridazines, a heterocyclic system common to a number of subtype selective GABA-A agonists; see: Collins, I.; Castro, J. L.; Street, L. J. Tetrahedron Lett. 2000, 41, 781. Sparey, T. J.; Harrison, T. Tetrahedron Lett. 1998, 39, 5873. Chloropyridazines are also useful as interleukin-1β converting enzyme inhibitors, see: Dolle, R. E.; Hoyer, D.; Rinker, J. M.; Morgan, T.; Schmidt, S. J.; Helaszek, C. T.; Ator, M. A. Bioorg. Med. Chem. Lett. 1997, 7, 1003.
16. Samaritoni, J. G.; Babbitt, G. J. Heterocycl. Chem. 1991, 28, 583.
17. We thank a reviewer for suggesting this explanation.
18. The low yields using amino acids other than glycine are unlikely solely due to increased sterics. The Minisci reaction accommodates sterically hindered alkyl radicals as demonstrated by the addition of the tert-butyl radical (derived from pivalic acid) in 90% yield under these reaction conditions, see also Samaritoni, J. G. Org. Prep. Proced. Int. 1988, 20, 117.