Organic Letters
Organic Letters
4 years ago

Fiaud’s Acid: A Brønsted Acid Catalyst for Enantioselective Friedel–Crafts Alkylation of Indoles with 2-Alkene-1,4-diones

Fiaud’s Acid: A Brønsted Acid Catalyst for Enantioselective Friedel–Crafts Alkylation of Indoles with 2-Alkene-1,4-diones
Sreya Gupta, Madhumita Mandal, Lukas Hintermann, Parasuraman Jaisankar, Anushree Achari, Sourav Chatterjee
Fiaud’s acid (trans-1-hydroxy-2,5-diphenylphospholane 1-oxide), a phospholane-based phosphinic acid, is introduced as an efficient chiral Brønsted acid catalyst that mediates the asymmetric Friedel–Crafts alkylation of indoles with 2-butene-1,4-diones. With a catalyst loading of 10 mol %, the reaction proceeded smoothly to afford 2-(indol-3-yl)butane-1,4-diones in high yield (up to 82%) and high enantioselectivity (up to 91% ee, one such product showed enhanced ee of 98% after recrystallization). The reaction conditions are sufficiently mild to tolerate sensitive functionality at room temperature and are therefore suitable for the synthesis of complex targets.

Publisher URL: http://dx.doi.org/10.1021/acs.orglett.7b01383

DOI: 10.1021/acs.orglett.7b01383

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.