Synthesis and structure of 2,6-di-tert-butyl-1,4-benzoquinone-4N-(8-tosylamino-1-naphthyl) imine
摘要:
The structure of 2,6-di-tert-butyl-1,4-benzoquinone-4-N-(8-tosylamino-1-naphthyl)imine (IId) has been studied as a model for the open form of thermo- and photochromic compounds in the cyclohexadienoneperimidine series (I), in which rearrangement occurs due to C(spiro)-N bond cleavage and N --> N proton transfer upon thermal or photoexcitation. Introduction of a bulky, electron-withdrawing tosyl substituent to the nitrogen atom stabilizes the open quinoneimine form, both in the crystalline state and in solution. The cyclohexadienone fragment is nonplanar and exists in a "boat" configuration. The open quinoneimine structure is retained upon replacement of the tosyl substituent by a less bulky electron-withdrawing acetyl substituent, suggesting that electronic factors are decisive in formation of the open structure.