Nonplanar Aromatic Compounds. 3. A Proposed New Strategy for the Synthesis of Buckybowls. Synthesis, Structure and Reactions of [7]-, [8]- and [9](2,7)Pyrenophanes
| Autor: | James J. Fleming, Graham J. Bodwell, David O. Miller, Michael R. Mannion |
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| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | The Journal of Organic Chemistry. 65:5360-5370 |
| ISSN: | 1520-6904 0022-3263 |
| DOI: | 10.1021/jo0007027 |
| Popis: | A new strategy for the synthesis of Buckybowls is presented and initial attempts to implement it are reported. This involves annulation of further rings onto polycyclic aromatic systems that prefer to be planar but have been “pre-bent” by the installation of a tether. Pyrenophane 2b reacts with TCNE and PTAD to give 1:1 and 1:2 adducts, respectively. The less strained pyrenophane 2c is unreactive toward TCNE but gives a 1:2 adduct with PTAD. Attempted electrophilic aromatic brominations of pyrenophane 2e under a variety of conditions were unsuccessful, as were attempts to brominate cyclophanediene 1c, the direct synthetic precursor of 2c. Tether cleavage and addition reactions occurred rather than substitution. In an effort to circumvent tether cleavage problems, [7]-, [8]- and [9](2,7)pyrenophanes 22b−d were prepared. However, attempted bromination and Friedel−Crafts acylations failed. Evidence for the fleeting existence of [6](2,7)pyrenophane 22a was also obtained. Comparison of structural data (X-ray a... |
| Databáze: | OpenAIRE |
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