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Sunday, 27 September 2015

Heck and Sonogashira couplings in aqueous media – application to unprotected nucleosides and nucleotides

Heck and Sonogashira couplings in aqueous media – application to unprotected nucleosides and nucleotides
Amongst all synthetic nucleosides having high potential biological activities, C5-modified pyrimidines and C7-deaza or C8-modified purines have been particularly studied. These main chemical modifications have been developed using palladium cross-coupling reactions. This review focus on both Heck and Sonogashira cross-coupling of nucleosides using different aspects of the twelve principles of green chemistry: use of aqueous medium and no protection/deprotection steps.
Heck cross-coupling reaction in aqueous solution was developed using only Pd(II) as a pre-catalyst in water and in CH3CN/H2O.
The first Heck cross-coupling reaction starting from deprotected nucleoside was reported in 1998 by Barbas et al. [16]. Starting from 5-iodo-2’-deoxyuridine (1) and allyl amide 2 in presence of Na2PdCl4 (80 mol%) as palladium source in sodium acetate buffer (0.1 M, pH = 5.2) as solvent at room temperature for 18 hours, (E)-[3-(trifluoroacetamido)propenyl]-2’-deoxyuridine (3) was isolated in 44% yield (Scheme 1). Compound 3 is a precursor of functionalized dUTP derivatives that are substrates for thermostable DNA polymerases. Nucleoside analogue 3 was obtained a few years later in the same range of yields by Williams et al. using the same experimental conditions[17].

Scheme 2
Synthesis of ferrocene analogue 65 and 66.

Scheme 3
Synthesis of phenylalanine analogues 67 and 68.

Heck and Sonogashira couplings in aqueous media – application to unprotected nucleosides and nucleotides

Gwénaëlle Hervé1 and Christophe Len12*
1Université de Technologie de Compiègne, Ecole Supérieure de Chimie Organique et Minérale, EA4297, Centre de recherche de Royallieu, Compiègne Cedex, BP20529, F-60205, France

2Department of Chemistry, University of Hull, England HU6 7RX, UK
Sustainable Chemical Processes 2015, 3:3  doi:10.1186/s40508-015-0029-2

The electronic version of this article is the complete one and can be found online at:http://www.sustainablechemicalprocesses.com/content/3/1/3
LEN Christophe
Head of Research, Scientific Council
Higher School of organic and inorganic chemistry


  • Sep 2012–present,Honorary Professor
    University of Hull · Department of Chemistry
    United Kingdom · Hull
  • Sep 2008–present,Professor (Full)
    Université de Technologie de Compiègne · Transformations Intégrées de la Matière Renouvelable (TIMR) - EA 4297
    France · Compiègne
  • Sep 2004–Sep 2008,Professor (Full)
    Université de Poitiers · Département de Chimie (IUTP)
    France · Poitiers
  • Sep 1997–Aug 2004, Professor (Assistant),Université de Picardie Jules Verne · LG - Laboratoire des glucides
    France · Amiens
 Centre de recherche de Royallieu, Compiègne Cedex


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///////Heck, Sonogashira, Green chemistry, Water