Stereospecific C-N Bond Cleavage of 4-Silylated 1, 2-Thiazetidine 1, 1-Dioxides with EtAlCl2 or AlCl3 : Formation of (E)-Vinylsulfonamides
Stereospecific C-N Bond Cleavage of 4-Silylated 1, 2-Thiazetidine 1, 1-Dioxides with EtAlCl2 or AlCl3 : Formation of (E)-Vinylsulfonamides
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DOI：
10.1248/cpb.46.757
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发表时间：
1998-05
影响因子：
1.7
通讯作者：
T. Iwama;Atsuko Takagi;T. Kataoka
中科院分区：
文献类型：
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作者：
T. Iwama;Atsuko Takagi;T. Kataoka
1，2-硫杂环丁烷-1，1-二氧化物(β-舒坦斯)3经硅烷化反应立体选择性地合成了(3R*，4S*)-4-单硅基-β-舒坦斯4。以三甲基硅氯为原料合成了二硅化β-舒坦斯5。用EtAlCl2处理4-单硅基-β-磺酰胺4，由于硅基的β-阳离子稳定，生成(E)-乙烯基磺酰胺(E)-7，导致立体专一性的C-N键断裂。(E)-α-硅基苯磺酰胺(E)-7J-L是由4，4-二硅基-β-磺胺5与EtAlCl2反应生成的。4-硅基-β-磺胺与三氯化铝反应生成N-脱烷基(E)-乙烯基磺酰胺。在四丁基氟化铵和BF3·Et2O存在下，(E)-α-硅基苯磺酰胺(E)-10与苯甲醛反应生成烯丙醇(E)-12。
Monosilylation of 1, 2-thiazetidine 1, 1-dioxides (β-sultams) 3 gave (3R*, 4S*)-4-monosilyl-β-sultams 4 stereoselectively. Disilylated β-sultams 5 were obtained by the use of trimethylsilyl chloride. Treatment of 4-monosilyl-β-sultams 4 with EtAlCl2 caused stereospecific C-N bond cleavage owing to β-cation stabilization of the silicon group to provide (E)-vinylsulfonamides (E)-7. (E)-α-Silylstyrylsulfonamides (E)-7j-l were generated in the reaction of 4, 4-disilyl-β-sultams 5 with EtAlCl2. Reaction of 4-silyl-β-sultams with AlCl3 afforded N-dealkylated (E)-vinylsulfonamides in good yields. Reaction of (E)-α-silylstyrylsulfonamide (E)-10 with benzaldehyde in the presence of tetrabutylammonium fluoride and BF3·Et2O provided the allylic alcohol (E)-12.