Reductive allylation of pyrrole with allylboranes. Synthesis oftrans- andcis-2,5-disubstituted pyrrolidines
作者:Yu. N. Bubnov、E. V. Klimkina、L. I. Lavrinovich、A. Yu. Zykov、A. V. Ignatenko
DOI:10.1007/bf02494816
日期:1999.9
(heating with triallylborane at 190 °C) was developed and a series ofN-substituted derivatives of these pyrrolidines was synthesized. A method for the preparative synthesis of nonsymmetrically substitutedtrans- andcis-2-alkyl(phenyl)-5-allylpyrrolidines, based on reductive allylboration of pyrrole followed by 1,2-addition of RLi to the 5-allyl-1-pyrroline that formed, was also developed. A direct confirmation
吡咯在用 β,γ-不饱和有机硼衍生物(三烯丙基硼烷、烯丙基(二丙基)硼烷和三烯基硼烷)和醇类连续处理后发生还原性单烯丙基化和二烯丙基化,得到 2-烯丙基化 3-吡咯啉和反式 2,5-二烯丙基化吡咯烷。第一个和第二个硼烯丙基片段添加到杂环中进行重排。开发了一种将反式-2,5-二烯丙基吡咯烷转化为顺式异构体的方法(用三烯丙基硼烷在190°C下加热),并合成了这些吡咯烷的一系列N-取代衍生物。一种制备非对称取代的反式和顺式-2-烷基(苯基)-5-烯丙基吡咯烷的方法,基于吡咯的还原烯丙基硼化,然后将 RLi 1,2-加成到形成的 5-烯丙基-1-吡咯啉,也被开发了。获得了在烯丙基硼烷的作用下中间体形成 2H-和 3H-吡咯互变异构体的直接确认。2H-吡咯与BF3的加合物通过NMR光谱检测。