2-Ns-Protected β-amino Weinreb amides were synthesized by aminochlorination of α,β-unsaturated Weinreb amides in an ionic liquid, 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([BMIM][NTf2]). Processed without the use of metal catalysts or the need of an inert gas atmosphere, the presented process can be readily performed as a one-pot synthesis at room temperature. Moreover, the preparation has the distinct advantages of the use of 2-NsNCl2 as an inexpensive and stable nitrogen/halogen source and the ionic liquid as a recyclable reaction media. Nine examples were examined, and modest to good isolated chemical yields (40–83%) were obtained.
使用
离子液体1-正丁基-3-甲基
咪唑双(
三氟甲烷磺酰)
亚胺([BMIM][NTf
2])对α,β-不饱和Weinreb酰胺进行
氨基
氯化反应,合成了2-Ns-保护的β-
氨基Weinreb酰胺。该过程无需使用
金属催化剂或惰性气氛,可在室温下轻松进行一锅法合成。此外,该合成方法具有使用2-NsNCl
2作为廉价且稳定的氮/卤素源和
离子液体作为可回收反应介质的独特优点。共合成了九个样品,获得了适中至良好的
化学收率(40-83%)。