Construction of Indole Structure on Pyrroloindolines via AgNTf<sub>2</sub>-Mediated Amination/Cyclization Cascade: Application to Total Synthesis of (+)-Pestalazine B
作者:Hiroyuki Hakamata、Hirofumi Ueda、Hidetoshi Tokuyama
DOI:10.1021/acs.orglett.9b01399
日期:2019.6.7
N-linked indole structure was constructed on the 3a-position of pyrroloindoline derivatives via a cascade process involving silver-mediated amination of bromopyrroloindolines with 2-ethynylanilines with subsequent 5-endo-dig cyclization. In this reaction, AgNTf2 was used as a tandem reagent, which activated the bromo group as a σ-Lewis acid and the alkyne moiety as a π-Lewis acid. Switching from the initial
一个Ñ -连接的经由涉及bromopyrroloindolines的银介导的胺化与2- ethynylanilines与级联过程构建上pyrroloindoline衍生物的图3a-位置吲哚结构随后5-内切挖环化。在该反应中,将AgNTf 2用作串联试剂,其将溴基活化为σ-路易斯酸,并将炔基部分活化为π-路易斯酸。通过控制温度来进行从初始步骤到第二步骤的切换。该方案适用于各种吡咯并吲哚啉,α-咔啉和呋喃二氢吲哚的合成以及二聚吲哚生物碱(+)-pestalazine B的总合成。