Synthesis of (Z)-enediynes via stereoinvertive nucleophilic substitution of (E)-sulfonylethenes with arylethynide, and their aggregation-induced optical properties

Y. Akagi, H. Watanabe, T. Sakami, S. Furumatsu, S. Yamada, R. Maki, Y. Okuda, H. Akashi, K. Wakamatsu, Y. Kusano, A. Orita

 (Z)-Enediynes were successfully synthesized from a trio of terminal ethynes through consecutive three-step reactions: iodosulfonylation of ethyne with I 2 / PhSO 2 Na, followed by ethynylations of iodo and sulfonyl moieties of the resulting iodosulfonylethene via Sonogashira−Hagihara coupling and nucleophilic addition− elimination, respectively. The molecular structure of the obtained (Z)-enediyne was fully characterized by X-ray crystal structure analysis, revealing that the nucleophilic substitution of (E)-sulfonylethene with arylethynide underwent a selective stereo- inversion. The (Z)-enediynes exhibited photoluminescence in both the solution and solid states (crystals and powders). Ph 2 N-substituted derivatives showed remarkable solvatofluorochromism, and upon replacing the solvent from toluene to acetonitrile, the emission color changed from blue to yellow.

The Journal of Organic Chemistry

89

23

17122

17132

doi.org/10.1021/acs.joc.4c01457