Synthesis of 3-Acyloxyindolenines by TiCl<sub>3</sub>-Mediated Reductive Cyclization of 2-(<i>ortho</i>-Nitroaryl)-Substituted Enol Esters
作者:Dina V. Boyarskaya、Alberto Ongaro、Cyril Piemontesi、Qian Wang、Jieping Zhu
DOI:10.1021/acs.orglett.2c02860
日期:2022.9.30
In the presence of TiCl3, the reductive cyclization of tetrasubstituted enol esters bearing a 2-(ortho-nitroaryl) substituent affords 3-acyloxy-2,3-disubstituted indolenines in good yields. A domino process involving the partial reduction of nitro to a nitroso group followed by 5-center-6π-electrocyclization, 1,2-acyloxy migration, and the further reduction of the resulting nitrone intermediate accounts
在TiCl 3存在下,带有2-(邻-硝基芳基)取代基的四取代烯醇酯的还原环化以良好的收率得到3-酰氧基-2,3-二取代的二氢吲哚。多米诺骨牌过程涉及将硝基部分还原为亚硝基,然后进行 5-中心-6π-电环化、1,2-酰氧基迁移以及所得硝酮中间体的进一步还原,这是反应结果的原因。如此获得的二氢吲哚通过一系列皂化和半频哪醇重排顺利转化为 2,2-二取代羟吲哚。