Reactions of Diphenyl(phenylethynyl)selenonium Salts with Active Methylene Compounds and Amides: First Isolation of Oxyselenuranes [10-Se-4(C3O)] as a Reaction Intermediate.
The reaction of the diphenyl(phenylethynyl)selenonium triflate 1a with active methylene compounds 5 and t-BuOK in THF gave furan derivatives 6. The [10-Se-4(C3O)] selenuranes 8a and 8b could be isolated from the reactions with benzoylacetonitrile 5f and with 1,3-indandione 5g, respectively, as reaction intermediates. The structures of the selenuranes 8 were elucidated by X-ray crystallography and (77)Se high-resolution solid-state NMR spectroscopy. The selenuranes 8 underwent ligand coupling on standing at room temperature or refluxing in chloroform and gave the furan derivatives 6 and the ring-opened product 9. Similarly, the reaction of 1a with benzamide 13a and pivalamide 13d in the presence of NaH in THF afforded oxazole derivatives 14.
Kataoka
Tadashi
T
Gifu Pharmaceutical University, 6-1 Mitahora-higashi 5-chome, Gifu 502-8585, Japan, Faculty of Education, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan, and Faculty of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-osaka, Osaka 577-8502, Japan.
Watanabe Si
Shin-ichi
Yamamoto
Keiichirou
K
Yoshimatsu
Mitsuhiro
M
Tanabe
Genzoh
G
Muraoka
Osamu
O