Skip to main content
SpringerLink
Log in

Fluorinated photoremovable protecting groups: the influence of fluoro substituents on the photo-Favorskii rearrangement

  • Paper
  • Published:
Photochemical & Photobiological Sciences Aims and scope Submit manuscript

Abstract

To further explore the nature of the photo-Favorskii rearrangement and its commitment to substrate photorelease from p-hydroxyphenacyl (pHP), an array of ten new fluorinated pHP γ-aminobutyric acid (GABA) derivatives was synthesized and photolyzed. The effects of fluorine substitution on the chromophore and the photophysical and photochemical properties of these new chromophores were shown to be derived primarily from the changes in the ground state pKa of the phenolic groups. The quantum yields and rate constants for release are clustered around Φdis = 0.20 ± 0.05 and kr = 8 ± 7 × 107 s−1 (H2O), respectively. The triplet lifetimes of the pHP GABA derivatives were concentrated in the range of 0.4–6.0 ns (H2O). The corresponding deprotonated conjugate bases displayed reduced efficiencies by 50% or more (one exception) and exhibited a weak fluorescence in pH 8.2 buffer. Pump-probe spectroscopy studies have further defined the rates of intersystem crossing and the lifetimes of the reactive triplet state of the fluoro pHP chromophore.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Notes and references

  1. Dynamic studies in Biology, Phototriggers, Photoswitches, and Caged Compounds, ed. M. G. Goeldner and R. Givens, Wiley-VCH, Weinheim, 2005.

    Google Scholar 

  2. C. H. Park and R. S. Givens, New Photoactivated Protecting Groups. 6. p-Hydroxyphenacyl: A New Phototrigger for Chemical and Biological Probes, J. Am. Chem. Soc., 1997, 119, 2453–2463.

    Article  CAS  Google Scholar 

  3. D. M. Lemal, Perspective on Fluorocarbon Chemistry, J. Org. Chem., 2004, 69, 1–11.

    Article  CAS  Google Scholar 

  4. P. Jeschke, The Unique Role of Fluorine in the Design of Active Ingredients for Modern Crop Protection, Chem. Bio. Chem, 2004, 5, 570–589.

    Article  CAS  Google Scholar 

  5. P. G. Conrad II, R. S. Givens, J. F. W. Weber and K. Kandler, New Phototriggers 10: Extending the p,p* Absorption to Release Peptides in Biological Media, Org. Lett., 2000, 2, 1545–1547.

    Article  CAS  Google Scholar 

  6. J. K. Stille, The Palladium Catalyzed Cross-Coupling Reactions of Organotin Reagents with Organic Electrophiles, Angew. Chem., Int. Ed. Engl., 1986, 25, 508–524.

    Article  Google Scholar 

  7. C. Ma, W. S. Chan, W. M. Kwok, P. Zuo and D. L. Phillips, Time-Resolved Resonance Raman Study of the Triplet State of the p-Hydroxyphenacyl Acetate Model Phototrigger Compound, J. Phys. Chem. B, 2004, 108, 9264–9276.and subsequent papers.

    Article  CAS  Google Scholar 

  8. C. G. Hatchard and C. A. Parker, A New Sensitive Chemical Actinome-ter. II. Potassium, Ferrioxalate as a Standard Chemical Actinometer, Proc. R. Soc. London, Ser. A, 1956, 235, 518–536.

    Article  CAS  Google Scholar 

  9. P. G. Conrad II, R. S. Givens, J. F. W. Weber and K. Kandler, New Phototriggers: Extending the p-Hydroxyphenacyl p-p*Absorption Range, Org. Lett., 2000, 2(11), 1545–1547.

    Google Scholar 

  10. R. S. Givens, D. Heger, Y. Kamdzhilov, M. Mac, E. Cope, J. I. Lee and J. Wirz, The Photo-Favorskii Reaction of p-Hydroxyphenacyl Compounds is Initiated by Water-Assisted, Adiabatic Extrusion of a Triplet Biradical, J. Am. Chem Soc., 2008, 130, 3307–3309.

    Article  CAS  Google Scholar 

  11. P. G. Conrad, R. S. Givens, B. Hellrung, C. S. Rajesh, M. Ramseier and J. Wirz, P-Hydroxyphenacyl Phototriggers: The Reactive Excited State of Phosphate Photorelease, J. Am. Chem. Soc., 2000, 122, 9346–9348.

    Article  CAS  Google Scholar 

  12. P. Zuo, C. Ma, W. M. Kwok, W. S. Chan and D. L. Phillips, Time Resolved Resonance Raman and Density Functional Theory Study of the Deprotonation Reaction of the Triplet State of p-Hydroxyacetophenone in Water Solution, J. Org. Chem., 2005, 70, 8661–8675.

    Article  CAS  Google Scholar 

  13. J. C. Anderson and C. B. Reese, Tetrahedron Lett., 1962, 1, 1–4.

    Article  Google Scholar 

  14. D. J. Desilets, P. T. Kissinger and F. E. Lytle, Improved Method for Determination of Stern-Volmer Quenching Constants, Anal. Chem., 1987, 59, 1244–1246.

    Article  CAS  Google Scholar 

  15. SYBYL 7.2, The Tripos Associates, St. Louis, MO, 2007.

  16. M. Clark, R. D. Cramer and N. Van Opdenbosch, Validation of the General Purpose Tripos 5.2 Force Field, J. Comput. Chem., 1989, 10, 982–1012.

    Article  CAS  Google Scholar 

  17. M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman, J. A. Montgomery, Jr., T. Vreven, K. N. Kudin, J. C. Burant, J. M. Millam, S. S. Iyengar, J. Tomasi, V. Barone, B. Mennucci, M. Cossi, G. Scalmani, N. Rega, G. A. Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, M. Klene, X. Li, J. E. Knox, H. P. Hratchian, J. B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E. Stratmann, O. Yazyev, A. J. Austin, R. Cammi, C. Pomelli, J. Ochterski, P. Y. Ayala, K. Morokuma, G. A. Voth, P. Salvador, J. J. Dannenberg, V. G. Zakrzewski, S. Dapprich, A. D. Daniels, M. C. Strain, O. Farkas, D. K. Malick, A. D. Rabuck, K. Raghavachari, J. B. Foresman, J. V. Ortiz, Q. Cui, A. G. Baboul, S. Clifford, J. Cioslowski, B. B. Stefanov, G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R. L. Martin, D. J. Fox, T. Keith, M. A. Al-Laham, C. Y. Peng, A. Nanayakkara, M. Challacombe, P. M. W. Gill, B. G. Johnson, W. Chen, M. W. Wong, C. Gonzalez and J. A. Pople, GAUSSIAN 03 (Revision C.02), Gaussian, Inc., Wallingford, CT, 2004.

    Google Scholar 

  18. A. D. Becke, Density-Functional Thermochemistry III. The, Role of Exact Exchange, J. Chem. P hys., 1993, 98, 5648–5652.

    Article  CAS  Google Scholar 

  19. R. Ditchfield, W. J. Hehre and J. A. Pople, Self-Consistent Molecular-Orbital Molecules IX. Extended, Gaussian-Type Basis for Molecular-Orbital Studies of Organic Molecules, J. Chem. P hys., 1971, 54, 724–728.

    Article  CAS  Google Scholar 

  20. J. A. Pople, R. Seeger and R. Krishan, Variational Configuration Interaction Methods and Comparisons with Perturbation Theory, Int. J. Quant. Chem. Symp., 1977, 11, 149–163.

    Article  CAS  Google Scholar 

  21. C. J. Hawker, R. Lee and J. M. Frechet, One Step Synthesis of Hyperbranched Dendridic Polyesters, J. Am. Chem. Soc., 1991, 113, 4583–4588.

    Article  CAS  Google Scholar 

  22. P. J. Machin, D. N. Hurst, R. M. Bradshaw, L. C. Blaber, D. T. Burden, A. D. Fryer, R. A. Melarange and C. Shivdasani, b1-Selective Adrenoceptor Antagonists 2. 4-Ether-Linked Phenoxypro-panolamines, J. Med. Chem, 1983, 26, 1570–1576.

    Article  CAS  Google Scholar 

  23. M. Kosugi, T. Sumiya, Y. Obara, M. Suzuki, H. Sano and T. Migita, (a-Ethoxyvinyl) tributyltin; an efficient reagent for the nucleophilic acetylation of organic halides via palladium catalysis, Bull. Chem. Soc. Jpn., 1987, 60, 767–768.

    Article  CAS  Google Scholar 

  24. S. Paul, V. Gupta, R. Gupta and A. Loupy, Microwave-Induced Selective Synthesis of a-Bromo and a,a-Dibromoalkanones Using Dioxane-Dibromide and Silica Gel under Solvent Free Conditions, Tetrahedron Lett., 2003, 44, 439–442.

    Article  CAS  Google Scholar 

  25. T. Hiyama and M. Fujita, Fluoride Ion Catalyzed of Aldehydes and Ketones with Hydrosilanes. Synthetic and Mechanistic Aspects and an Application to the Threo-Directed Reduction of a-Substituted Alkanones, J. Org. Chem., 1988, 53, 5405–5415.

    Article  Google Scholar 

  26. J. P. Marsh and L. Goodman, Removal of O-Benzyl Blocking Groups with Trifluoroacetic Acid, J. Org. Chem., 1965, 30, 2491–2492.

    Article  CAS  Google Scholar 

  27. B. Dyck, L. Zhao, J. Tamiya, J. Pontillo, S. Hudson, B. Ching, C. E. Heise, J. Wen, C. Norton, A. Madan, D. Schwartz, W. Wade and V. S. Goodfellow, Substituted Chromones and Quinolines as Potent Melanin-Concentrating Hormone Receptor 1 Antagonists, Bio. org. Med. Chem. Lett., 2006, 16, 4237–4242.

    Article  CAS  Google Scholar 

  28. Combi-Blocks, LLC. 7949 Silverton Avenue, Suite 915, San Diego, CA, 92126.USA.

Download references

Author information

Authors and Affiliations

  1. Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, 2010 Malott Hall, Lawrence, KS, 66045, USA

    Kenneth F. Stensrud & Richard S. Givens

  2. Departement Chemie der Universität Basel, Klingelbergstrasse 80, CH-4056, Basel, Switzerland

    Dominik Heger, Peter Šebej & Jakob Wirz

Authors
  1. Kenneth F. Stensrud
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Dominik Heger
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Peter Šebej
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Jakob Wirz
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Richard S. Givens
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Richard S. Givens.

Additional information

This paper was published as part of the themed issue in honour of Jakob Wirz.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Stensrud, K.F., Heger, D., Šebej, P. et al. Fluorinated photoremovable protecting groups: the influence of fluoro substituents on the photo-Favorskii rearrangement. Photochem Photobiol Sci 7, 614–624 (2008). https://doi.org/10.1039/b719367j

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1039/b719367j

Search

Navigation