Photoremovable protecting groups: Variations on the photo-Favorskii rearrangement – a mechanistic study

ORGN 641

Richard S Givens, givensr@ku.edu1, Kenneth F. Stensrud, nero@ku.edu1, Elizabeth D. Cope, edcope@ku.edu1, Chamani Perera1, Sanjeewa Senadheera1, Chicheng Ma, macc@ku.edu2, and Shaorong Yang1. (1) Department of Chemistry, University of Kansas, 5010 Malott Hall, 1251 Wescoe Hall Dr, Lawrence, KS 66045, (2) Center for Environmentally Beneficial Catalysis, University fo Kansas, 1501 Wakarusa Drive, Lawrence, KS 66047
Recent studies in our group and others1 have delineated many of the mechanistic parameters responsible for the photo-Favorskii rearrangement of p-hydroxyphenacyl derivatives (pHP-X, 1) to the hydroxyphenyl acetic acids (2). Systematic variation of pH, solvent, substituents, and nucleofuges have provided a platform for photophysical and photochemical investigations of the rearrangement. These studies in combination with theoretical treatments suggest a triplet adiabatic stepwise rearrangement through a dienedione intermediate 3. The results and several applications of pHP photoremovable protection will be discussed.

1 Ma, C. .; Kwok, W. M.; Chan, W. S.; Du, Y.; Kan, J. T. W.; Phillips, D.L.; . J. Am. Chem. Soc. (2006), 128, 2558-2570; Zhang, K.; Corrie, J. E. T.; Munasinghe, V. R. N.; Wan, P. J. Am. Chem. Soc. (1999), 121, 5625-5632

 

Sixty Years of Physical Organic Chemistry
8:10 AM-12:00 PM, Wednesday, August 22, 2007 BCEC -- Ballroom, Oral

Division of Organic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007