Aza-Wittig Rearrangements of<i>N</i>-Benzyl and<i>N</i>-Allyl Glycine Methyl Esters. Discovery of a Surprising Cascade Aza-Wittig Rearrangement/Hydroboration Reaction
作者:Renata K. Everett、John P. Wolfe
DOI:10.1021/acs.joc.5b01286
日期:2015.9.18
Treatment of N-(arylmethyl)-N-aryl or N-allyl-N-aryl glycine methyl ester derivatives with nBu2BOTf and iPr2NEt effects an aza-Wittig rearrangement that provides N-aryl phenylalanine methyl ester derivatives and N-aryl allylglycine methyl ester derivatives, respectively, in good yield with moderate to good diastereoselectivity. Under similar conditions, analogous substrates bearing N-carbonyl groups
用n Bu 2 BOTf和i Pr 2 NEt处理N-(芳基甲基)-N-芳基或N-烯丙基-N-芳基甘氨酸甲酯衍生物会产生aza-Wittig重排,提供N-芳基苯丙氨酸甲酯衍生物和N -芳基烯丙基甘氨酸甲基酯衍生物,分别以高收率和中等至良好的非对映选择性而得到。在相似条件下,带有N-羰基的类似底物被转化为1,4,2-氧杂硼烷衍生物。另外,N-烯丙基-N-在升高的温度下经受类似条件的芳基甘氨酸甲酯衍生物进行aza- [2,3] -Wittig重排,然后进行随后的硼氢化氧化反应,得到取代的氨基醇产物。