ORGN 497 |
| Graphite heats rapidly upon microwave radiation. This has led to applications in which graphite may be used to “sensitize” thermal reactions. We are studying reactions most commonly accomplished at high temperatures (> 500ºC) using flash vapor pyrolysis. The question posed is whether graphite sensitization will effect high temperature transformations in a microwave oven. We describe this general approach as Graphite-Sensitized Microwave Flash Pyrolysis (GSMFP). We find that GSMFP may be extended to a wide range of high-temperature reactions. As one example, graphite-sensitized microwave reaction of azulene affords rearrangement to naphthalene. Other reactions observed include fragmentation of phthalic anhydride to ortho-benzyne, cleavage of aryl iodides to phenyl radicals and a variety of cycloaromatization reactions. Advantage is seen for less volatile substrates. For safety, reactions are conducted “open-vessel” under inert atmosphere in quartz tubes. This technique offers great promise for generation of reactive intermediates and provides the ability to carry out complex synthetic transformations. |
|
Physical Organic Chemistry, Metal-Mediated Reactions, Asymmetric Reactions and Syntheses
8:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Organic Chemistry |