Cyclisation versus 1,1-Carboboration: Reactions of B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>with Propargyl Amides
作者:Rebecca L. Melen、Max M. Hansmann、Alan J. Lough、A. Stephen K. Hashmi、Douglas W. Stephan
DOI:10.1002/chem.201301899
日期:2013.9.2
A series of propargyl amides were prepared and their reactions with the Lewis acidic compound B(C6F5)3 were investigated. These reactions were shown to afford novel heterocycles under mild conditions. The reaction of a variety of N‐substituted propargyl amides with B(C6F5)3 led to an intramolecular oxo‐boration cyclisation reaction, which afforded the 5‐alkylidene‐4,5‐dihydrooxazolium borate species
制备了一系列炔丙基酰胺,并研究了它们与路易斯酸性化合物B(C 6 F 5)3的反应。这些反应显示在温和条件下提供新颖的杂环。各种N取代的炔丙基酰胺与B(C 6 F 5)3的反应导致了分子内的羰基硼化环化反应,提供了5亚烷基-4,5-二氢恶唑硼酸盐。炔丙基仲酰胺在B(C 6 F 5)3中得到恶唑介导的(催化)环化反应。在氮原子附近不稳定的特殊情况下,由于5-亚烷基-4,5-二氢恶唑鎓硼酸盐物种的空间位阻增加(1,3-烯丙基菌株),因此有利于1,1-碳链化。