Alkylation/elimination from azetidinium ylides: an entry to functionalized acrylonitriles
作者:Cheikh Lo、Olivier David、François Couty
DOI:10.1016/j.tetlet.2013.11.092
日期:2014.1
Azetidinium triflates were reacted in a one-pot two-steps sequence involving, generation of an azetidinium ylide, its alkylation with an halide, and final regioselective Hofmann elimination of the produced alkylated azetidinium ion to yield substituted α,β-unsaturated nitriles bearing an aminoethyl side-chain. The scope of this sequence was examined, and was found to depend both on the steric hindrance
et杂三氟甲磺酸酯以一锅两步的顺序进行反应,包括生成ze丁啶鎓叶立德,将其烷基化为卤化物,以及最终的区域选择性霍夫曼消除所生成的烷基化a丁啶鎓离子,从而生成带有氨基乙基的取代的α,β-不饱和腈侧链。检查了该序列的范围,发现其既取决于起始氮杂环丁鎓盐中反应中心周围的空间位阻,也取决于反应的卤化物的性质。产生的丙烯腈进一步用于胺的DBU催化的共轭加成中,以产生具有非对映异构选择性的4-氨基-2-氨基甲基-丁腈,或者,得到C 2对称的环丙烷。