Two useful photolabile surfaces for solid-phase synthesis

Organic Letters

Volumn 2, Issue 6, 2000, Pages 851-853

  Ryba, Troy D ^a   Harran, Patrick G ^a  

^a UNIVERSITY OF TEXAS SOUTHWESTERN MEDICAL CENTER   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000414181     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol0056224     Document Type: Article

References (16)

1. The preparation and utility of photolabile linkers has been reviewed: (a) Gordon, K.; Balasubramanian, S. J. Chem. Technol. Biotechnol. 1999, 74, 835-851.
2. (b) Backes, B. J.; Ellman, J. A. Curr. Opin. Chem. Biol. 1997, 1, 86-93.
3. (c) Lloyd-Williams, P.; Albericio, F.; Giralt, E. Tetrahedron 1993, 49, 11065-11133.
4. (d) Pallai, V. N. R. Synthesis 1980, 1-26.
5. Compound 2 is prepared from known 2,2-dimethyl-3-(tert-butoxycarbonyl)amino-3-(2′-nitrophenyl)propionic acid. Sternson, S. M.; Schreiber, S. L. Tetrahedron Lett. 1998, 39, 7451-7454.
6. 4 to reconstitute, in part, a more selective nitration mixture. Nonselective nitration of 2-phenylcyclohexanone has been described: Prager, R. H.; Tippett, J. M.; Ward, A. D. Aust. J. Chem. 1978, 31, 1989-2001.
7. The conversion of 5 to 7 generates trace byproducts, none of which account for more than 5% of unrecovered mass. It is possible that one of these materials is a regioisomeric lactam.
8. TBTU = O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium tetrafluoroborate, DIPEA = N,N-diisopropylethylamine, HOBt = N-hydroxybenzotriazole.
9. Rodebaugh, R.; Fraser-Reid, B.; Geysen, H. M. Tetrahedron Lett. 1997, 38, 7653-7656.
10. 2 (TBTU, DIPEA, HOBt, DMF) affords the corresponding hydroxy amide in 82% isolated yield. Self-condensation and/or re-lactonized products are not detected. Moreover, there is no significant difference in immobilized yields using 9 or 10 on organic polymer supports (Tentagel, Argopore).
11. Newcomb, W. S.; Deegan, T. L.; Miller, W.; Porco, J. A., Jr. Technical Bulletin 012; Argonaut Technologies Inc.: San Carlos, CA. This information can be downloaded from www.argotech.com.
12. 2 at the 366 nm line (50 cm distance from the lamp).
13. (a) Holmes, C. P.; Jones, D. G. J. Org. Chem. 1995, 60, 2318-2319.
14. (b) Holmes, C. P. J. Org. Chem. 1997, 62, 2370-2380.
15. Krafft, G. A.; Randall Sutton, W.; Cummings, R. T. J. Am. Chem. Soc. 1988, 110, 301-303.
16. It is common to detect residual dibenzofulvene, accounting for ∼15% of the original loading capacity, when photolyzed glass particles (dark red after 2 h of irradiation) are re-subjected to DBU treatment.