DR ANTHONY MELVIN CRASTO,WorldDrugTracker, helping millions, A 90 % paralysed man in action for you, I am suffering from transverse mylitis and bound to a wheel chair, With death on the horizon, nothing will not stop me except God
DR ANTHONY MELVIN CRASTO Ph.D ( ICT, Mumbai) , INDIA 25Yrs Exp. in the feld of Organic Chemistry,Working for GLENMARK GENERICS at Navi Mumbai, INDIA. Serving chemists around the world. Helping them with websites on Chemistry.Million hits on google, world acclamation from industry, academia, drug authorities for websites, blogs and educational contribution
n

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
http://www.sustainablechemicalprocesses.com/content/3/1/3
 
LEN Christophe
Head of Research, Scientific Council
Higher School of organic and inorganic chemistry
 https://www.researchgate.net/profile/Christophe_Len/info

RESEARCH EXPERIENCE

  • 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











 DRUG APPROVALS BY DR ANTHONY MELVIN CRASTO .....FOR BLOG HOME CLICK HERE


Join me on Linkedin

View Anthony Melvin Crasto Ph.D's profile on LinkedIn

Join me on Facebook FACEBOOK
Join me on twitterFollow amcrasto on Twitter     
Join me on google plus Googleplus

 amcrasto@gmail.com

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

2 comments: