Dihydropyrene annelated with dihydrothieno[3.4-b]pyrazine: synthesis and photoswitching property

✍ Scribed by Tsuyoshi Sawada; Mizue Kuroki; Tomoya Ogawa; Kentaro Shimojo; Kazufumi Chifuku; Hirotaka Ihara

• Book ID: 104097880
• Publisher: Elsevier Science
• Year: 2010
• Tongue: French
• Weight: 504 KB
• Volume: 51
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2010.05.092

✦ Synopsis

In this study, 9,10-diacetoxyl-2,7-di-tert-butyl-trans-10b,10c-dimethyl-10b,10c-dihydropyrene annelated with a dihydrothieno [3.4-b]pyrazine unit (1a) was prepared, for the first time, from 5,13-di-tertbutyl-8,16-dimethyl-1,2,9,10-tetrahydroxy[2.2]metacyclophane and 3,4-diaminothiophene in two steps. The photoisomerization property of 1 was investigated by UV and 1 H NMR spectroscopies, and the quantitative isomerization between the more stable dihydropyrene (DHP) form and the less stable metacyclophane-diene (MCPD) form was observed. A thermally induced return reaction from the MCPD to the DHP form was examined at various temperatures, and the reaction rate was 0.0049 min À1 at 45 °C, which is slower than that of the parent MCPD.