A facile one-pot synthesis of 2-(prop-2-yn-1-ylidene)-2,3-dihydro-1,4-thiazepines

An unprecedented method for the synthesis of 2-(prop-2-yn-1-ylidene)-2,3-dihydro-1,4-thiazepines from N-(2,4-pentadiynyl) beta-enaminones is reported. Upon treatment with Lawesson's reagent, N-(2,4-pentadiynyl) beta-enaminones were thionated to furnish N-(2,4-pentadiynyl) beta-enaminothiones, which immediately underwent 7-exo-dig cyclization to generate 2-(prop-2-yn-1-ylidene)-2,3-dihydro-1,4-thiazepines in one-pot. A general trend was observed for various N-(2,4-pentadiynyl) beta-enaminones and cyclization proceeded with broad functional group tolerance. This operationally easy method may provide quick access to a library of functionalized 1,4-thiazepines in the field of pharmaceutical chemistry.

Citation Formats
E. S. Yılmaz and M. Zora, “A facile one-pot synthesis of 2-(prop-2-yn-1-ylidene)-2,3-dihydro-1,4-thiazepines,” SYNTHETIC COMMUNICATIONS, 2020, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/69318.