Asymmetric Synthesis of Cyclopenta[c]chromenones

  • ChemPubSoc Europe Logo
  • Author: Angewandte Chemie International Edition
  • Published Date: 20 December 2018
  • Source / Publisher: Angewandte Chemie International Edition/Wiley-VCH
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
thumbnail image: Asymmetric Synthesis of Cyclopenta[<i>c</i>]chromenones

Coumarins and related structures are commonly found in pharmaceuticals, materials, and natural products. However, catalytic enantioselective synthesis methods for chiral cyclopenta[c]-fused chromenones, which are coumarin derivatives, with high asymmetric induction had not been realized to date.


Xiang-Yu Chen, Dieter Enders, RWTH Aachen University, Germany, and colleagues have developed the first N-heterocyclic carbene (NHC)-catalyzed quadruple-domino reaction for the asymmetric synthesis of cyclopenta[c]chromenones (pictured). The team used a tetracyclic NHC derived from aminoindanol as the catalyst, tetramethylethylenediamine (TMEDA) as the base, diphenoquinone as the oxidant, lithium chloride as a cooperative Lewis acid, and 1,2-dimethoxyethane (DME) as the solvent.


The method tolerates various enals and malonates bearing an ortho-hydroxy phenyl group. The protocol enables the direct organocatalytic assembly of cyclopenta[c]-fused chromenones in good yields and with high enantioselectivities. A subsequent reductive lactone–ester conversion under ring opening allows the preparation of highly functionalized cyclopentanes.


 

Article Views: 728

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

Bookmark and Share

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission. more


CONNECT:

ChemistryViews.org on Facebook

ChemistryViews.org on Twitter ChemistryViews.org on YouTube ChemistryViews.org on LinkedIn Sign up for our free newsletter


A product of ChemPubSoc Europe (16 European Chemical Societies)and Wiley-VCH