3,4-Dihydro-2<i>H</i>-pyrrole-2-carbonitriles: Useful Intermediates in the Synthesis of Fused Pyrroles and 2,2′-Bipyrroles
作者:Marco M. Nebe、Murat Kucukdisli、Till Opatz
DOI:10.1021/acs.joc.6b00393
日期:2016.5.20
3-dihydro-1H-pyrrolizines as well as 6,7,8,9-tetrahydro-5H-pyrrolo[1,2-a]azepines were obtained from these precursors in high yields in an alkylation/annulation sequence. The same conditions were applied in the synthesis of a 5,8-dihydroindolizine, which could easily be transformed to the corresponding indolizine by dehydrogenation. Furthermore, oxidative couplings of 3,4-dihydro-2H-pyrrole-2-carbonitriles with copper(II)-salts
含有吡咯部分的各种杂环结构是通过一锅法从容易获得的3,4-二氢-2 H-吡咯-2-腈合成的。从这些前体中获得了5,6,7,8-四氢吲哚并嗪,2,3-二氢-1 H-吡咯并嗪以及6,7,8,9-四氢-5 H-吡咯并[1,2- a ]氮杂以烷基化/环化顺序高收率。将相同的条件应用于5,8-二氢吲哚嗪的合成中,可以很容易地通过脱氢将其转化为相应的吲哚嗪。此外,3,4-二氢-2 H的氧化偶合根据反应条件,带有铜(II)盐的-吡咯-2-甲腈可提供2,2'-联吡咯以及5,5'-双(5-氰基-1-吡咯啉)。总体而言,这些方法可从市售起始原料中分两步高收率地获得各种含吡咯的杂环。