Preparation and reductive transformations of vinylogous sulfonamides (β-sulfonyl enamines), and application to the synthesis of indolizidines
作者:Joseph P. Michael、Charles B. de Koning、Tshepo J. Malefetse、Ibrahim Yillah
DOI:10.1039/b413379j
日期:——
Condensation between the methiodide salts of 1-alkylpyrrolidine-2-thiones and ethyl [(4-methylphenyl)sulfonyl]acetate or 1-[(4-methylphenyl)sulfonyl]propan-2-one afforded several 2-[[(4-methylphenyl)sulfonyl]methylene]pyrrolidines in good yield. These beta-sulfonyl enamines are sufficiently nucleophilic for cyclisation with internal electrophiles to give sulfone-substituted indolizines, potentially
1-烷基吡咯烷-2-硫酮的甲硫盐与[(4-甲基苯基)磺酰基]乙酸乙酯或1-[(4-甲基苯基)磺酰基]丙-2-酮的缩合得到几种2-[[((4-甲基苯基)]磺酰基]亚甲基]吡咯烷类化合物收率好。这些β-磺酰基烯胺具有足够的亲核性,可以与内部亲电试剂进行环化反应,从而得到砜取代的吲哚利嗪,这是潜在的有用的生物碱合成骨架。通过催化氢化或用硼氢化钠处理可选择性地立体还原乙烯基磺酰胺中的碳-碳双键,生成β-磺胺。β-酰基-β-磺酰基烯胺中的砜基可通过在THF-甲醇中用汞齐钠进行氢解反应而除去,得到烯胺酮。