Synthesis of spiro-containing 1,4-oxazepines from N-propargylic beta-enaminones

2018-03-18
Karadeniz, Eda
Kelgökmen, Yılmaz
Zora, Metin
An efficient and general method for the synthesis of spiro‐1,4‐oxazepines and 3,3‐dimethyl‐1,4‐oxazepines is reported. When treated with ZnI2 and AgSbF6 in refluxing DCE, cyclohexane‐embedded N‐propargylic β‐enaminones underwent 7‐exo‐dig cyclization to afford spiro‐1,4‐oxazepines, specifically 12‐methylene‐11‐oxa‐7‐azaspiro[5.6]dodeca‐7,9‐dienes, in good to high yields. Accordingly, N‐(1,1‐dimethyl)propargylic β‐enaminones produced 3,3‐dimethyl‐1,4‐oxazepines. Cyclization was found to be general for a diverse range of N‐propargylic β‐enaminones with high efficiency and broad functional group tolerance. This operationally easy method might provide quick access to a library of functionalized spiro and gem‐dimethyl‐substituted 1,4‐oxazepine derivatives of pharmacological interest.

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Citation Formats
E. Karadeniz, Y. Kelgökmen, and M. Zora, “Synthesis of spiro-containing 1,4-oxazepines from N-propargylic beta-enaminones,” 2018, vol. 255, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/54440.