2-Benzothiazolyl Propargyl Sulfides: Versatile Precursors for Enantiopure Allenes, E-α,β-Unsaturated Ketones and Z-Sulfonylalkenes
作者:Dagmar Kapeller、Philip Kocienski
DOI:10.1055/s-0030-1258259
日期:2010.11
described. The approach proceeds via a retro-ene reaction, initiated by lithium aluminium hydride mediated cleavage of benzothiazole from the respective (chiral) 2-benzothiazolyl propargyl sulfone precursors. As such, allenes in up to 92% yield are formed under evolution of sulfur dioxide at ambient temperature. Furthermore, a new and mild way to generate E-α,β-unsaturated ketones has been discovered. These
描述了一种新颖的立体定向路线,通往丙二烯。该方法通过逆烯反应进行,该反应由氢化锂铝介导的从各自的(手性的)2-苯并噻唑基炔丙基砜前体裂解苯并噻唑而引发。这样,在环境温度下,在释放出二氧化硫的情况下,生成了高达92%收率的丙二烯。此外,已经发现了产生E -α,β-不饱和酮的新的温和方法。通过在室温下用过氧化氢和催化量的钼酸铵处理2-苯并噻唑基炔丙基硫醚,可以约50%的产率形成这些底物。在研究过程中,还发现用硼氢化钠处理2-苯并噻唑基炔丙基砜可导致三键只还原为氢键。Z-双键。 丙二烯-α,β-不饱和酮-氧化-重排-砜