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CC BY-ND-NC 4.0 · Synthesis 2019; 51(05): 1178-1184
DOI: 10.1055/s-0037-1610404
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An Asymmetric Organocatalytic Aldol Reaction of a Hydrophobic Aldehyde in Aqueous Medium Running in Flow Mode

Lukas Schober
a   Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany   Email: harald.groeger@uni-bielefeld.de
,
Shahilan Ratnam
a   Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany   Email: harald.groeger@uni-bielefeld.de
,
Yasunobu Yamashita
a   Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany   Email: harald.groeger@uni-bielefeld.de
,
Niklas Adebar
a   Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany   Email: harald.groeger@uni-bielefeld.de
,
Matthias Pieper
a   Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany   Email: harald.groeger@uni-bielefeld.de
,
Albrecht Berkessel 
b   Department of Chemistry (Organic Chemistry), University of Cologne, Greinstrasse 4, 50939 Cologne, Germany
,
Volker Hessel
c   Micro Flow Chemistry & Process Technology, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
,
Harald Gröger  *
a   Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany   Email: harald.groeger@uni-bielefeld.de
› Author AffiliationsEU-Research Project ONE-FLOW (“Catalyst Cascade Reactions in ‘One-Flow’ within a Compartmentalized, Green-Solvent ‘Digital Synthesis Machinery’ – End-to-End Green Process Design for Pharmaceuticals”), Work programme: EU proposal 737266.
Further Information

Publication History

Received: 06 November 2018

Accepted: 09 November 2018

Publication Date:
07 January 2019 (online)

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Dedicated to Professor Dr. Jürgen Martens on the occasion of his 70th birthday

Published as part of the 50 Years SYNTHESIS – Golden Anniversary Issue

Abstract

Reaction conditions have been identified to conduct a one-pot asymmetric organocatalytic aldol reaction with a hydrophobic substrate in aqueous medium via a process running in flow mode. By employing a mixture of water and 2-propanol, a hydrophobic aldehyde and 3.6 mol% of an organocatalyst, this microreactor process affords the desired aldol adduct with a conversion of 74% and an enantioselectivity of 89% after a reaction time of 60 minutes.

Key words

aldol reaction - asymmetric catalysis - continuously running processes - flow chemistry - organocatalysis - water
 

  • References

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