New Route to Tetrasubstituted Allenes

  • Author: Vikki Cantrill
  • Published: 18 February 2013
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
  • Source / Publisher: Nature Chemistry/Nature Publishing Group
thumbnail image: New Route to Tetrasubstituted Allenes

Allenes are important synthetic intermediates in organic chemistry and biologically active molecules. Allenes have three carbon atoms connected by adjoining carbon–carbon double bonds that can make them axially chiral and often difficult to synthesize. However, a general strategy to synthesize fully substituted allenes by using asymmetric phase-transfer catalysis has been developed.

The method by Keiji Maruoka and colleagues, Kyoto University, Japan, uses cumulenolate, with three connected carbon–carbon double bonds (pictured), and a chiral phase-transfer catalyst to produce complex allenes.

An alleno-Mannich-type reaction and an alkylation reaction were studied. The best catalyst for the former was a 3,3′-disubstituted binaphthyl-based quaternary ammonium salt that gave an allene with a 90:10 diastereomeric ratio and 90 % enantiomeric excess (e.e.). For the latter, the catalyst was modified at the N-aryl group of the piperazine, and gave an 86:14 mix of regioisomers in 95 % e.e.

Article Views: 3361

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

If you would like to reuse any content, in print or online, from, please contact us first for permission and consult our permission guidance prior to making your request

Follow on Facebook Follow on Twitter Follow on YouTube Follow on LinkedIn Follow on Instagram RSS Sign up for newsletters

Magazine of Chemistry Europe (16 European Chemical Societies) published by Wiley-VCH