Department of Chemistry, University of Illinois at Chicago , Chicago, Illinois 60607, United States.
J Org Chem. 2018 Feb 2;83(3):1085-1094. doi: 10.1021/acs.joc.7b02638. Epub 2017 Nov 27.
A cascade reaction of N-aryl-α,β-unsaturated nitrones and electron-deficient allenes has been discovered that allows single-step access to 3-functionalized indoles that usually require preformation and alkylation of an indole precursor. The heterocycles prepared through the hydrogen bond donor catalyzed cascade reaction are poised to undergo a McMurry coupling to form previously synthetically elusive cycloheptanone-fused indoles. The scope of these transformations is discussed as well as mechanistic experiments describing proposed intermediates of the cascade reaction and an initial catalytic asymmetric example that generates a carbon stereocenter during the cascade process.
已发现 N-芳基-α，β-不饱和硝酮和缺电子烯丙基的级联反应，该反应允许一步法获得通常需要预先形成和吲哚前体烷基化的 3-官能化吲哚。通过氢键供体催化的级联反应制备的杂环可以进行 McMurry 偶联，形成以前难以合成的环庚酮稠合吲哚。讨论了这些转化的范围，以及描述级联反应的提议中间体的机理实验和在级联过程中产生碳立体中心的初始催化不对称实例。
