ORGN 224 |
| Radical cyclization reactions are important and versatile tools in organic synthesis. Most of these reactions include the use of toxic tin hydrides and a heavy element (typically iodine, bromine, selenium, or sulfur) to form the initial organic radical. The replacement of stoichiometric tin hydride reactions with catalytic reactions involving non-toxic reagents would render radical cyclizations more useful for pharmaceutical applications. We have developed radical cyclization reactions that use transition-metal hydrides to donate hydrogen atoms to substituted dienes, forming organic radicals that can then cyclize. In addition, performing the reaction in a hydrogen atmosphere regenerates the transition-metal hydride from the resulting metal radical, making the reaction catalytic. A model compound study was used to determine the rates of hydrogen atom transfer to variously substituted olefins. This newly developed method for radical cyclization reactions is not only tin-free but catalytic. |
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Metal-Mediated Reactions and Synthesis
8:00 AM-12:00 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. R06, Oral
Division of Organic Chemistry |