ORGN 238 |
Mechanistic studies of Scholl cascade reactions
| Pawel Rempala, Jiri Kroulik, and Benjamin T. King. Department of Chemistry, University of Nevada, Reno, NV 89557 |
| The Scholl reaction was investigated at the B3LYP/6-31G(d) level of theory for the conversion of a series of 1,2,...,n-polyphenylbenzenes (n = 3, 4, 6) to the corresponding planar polycyclic aromatic hydrocarbons. The formation of C-C bonds is stepwise, with a repetitive sequence of protonation, intramolecular electrophilic C-C bond formation, deprotonation, and oxidative dehydrogenation. An alternative mechanism involving the initial formation of a radical cation is unlikely due to high C-C bond formation barriers. The formation of the first C-C bond is rate determining, accounting for the ease of cascade Scholl condensations. The occasionally observed accumulation of intermediates is an electrochemical phenomenon. |
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Physical Organic Chemistry: Calculations, Mechanisms, Photochemistry, and High-Energy Species
8:00 AM-12:00 PM, Tuesday, March 30, 2004 Anaheim Convention Center -- 303A, Oral
Division of Organic Chemistry
The 227th ACS National Meeting, Anaheim, CA, March 28-April 1, 2004
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