作者:Zirong Zhang、David B. Collum
DOI:10.1021/acs.joc.9b01426
日期:2019.9.6
[2,3]-Sigmatropic rearrangements (Wittig rearrangements) of α-alkoxy oxazolidinone enolates are described. Whereas alkali metal enolates fail, owing to facile deacylation, boron enolates generated from di-n-butylboron triflate and triethylamine rearranged in good yields and high selectivities with exceptions noted. IR and NMR spectroscopies show the boron is chelated by the α-alkoxy group rather than
描述了α-烷氧基恶唑烷酮烯醇酸酯的[2,3]-适亲重排(Wittig重排)。碱金属烯醇盐由于容易的脱酰作用而失效,而由三氟甲磺酸二正丁基硼和三乙胺生成的硼烯醇盐以高收率和高选择性重排,但有例外。IR和NMR光谱表明,硼被α-烷氧基螯合,而不是在络合物和烯醇化物中更远端的恶唑烷酮羰基。重排产物包含烷氧基硼,该烷氧基硼保持未被任何羰基螯合。优化是由密度泛函理论计算指导的,表明缬氨酸衍生的恶唑烷酮将优于苯丙氨酸衍生的类似物。