The chemoselective transformation of common but unreactive C-H bonds to other functional groups hasthe potential to revolutionize chemical synthesis. The primary goal of the proposed research is to developrhodium porphyrin catalysts to activate and functionalize sp3 hybridized C-H bonds. Rhodium (II) porphyrincomplexes can stoichiometrically activate sp3 C-H bonds over sp2 C-H bonds without the need for directinggroups within the substrate while tolerating the types of functional groups present in bioactive compounds.This research will attempt to make this reaction more widely applicable by making the stoichiometric processinto catalytic one by using nitroxide radicals to turn the products of this C-H activation, rhodium (III) alkyl andhydride species, into rhodium (II) porphyrins and useful organic products, namely alkenes. Nitroxide radicalswere chosen for this study based on the known ability of these compounds to covert some rhodium (III)porphyrin hydrides to rhodium (II) porphyrins and the nitroxide promoted conversion of rhodium (III) pophyrinalkyls into alkenes. The new nitroxide radicals proposed herein will allow catalysis by avoiding known sidereactions of the rhodium (II) porphyrins with previously used nitroxide radicals.
| Hongay, Cintia F; Grisafi, Paula L; Galitski, Timothy et al. (2006) Antisense transcription controls cell fate in Saccharomyces cerevisiae. Cell 127:735-45 |
