W. Dąbkowski, I. Tworowska, J. Michalski
Sep 23, 2000
Citations
0
Influential Citations
11
Citations
Journal
Tetrahedron Letters
Abstract
Abstract 2,4-Dinitrophenol (DNP) is a remarkably efficient activator in the reaction of P(III) amides with nucleosides to give P(III) esters in excellent yield. Typical examples of this novel procedure are presented herein. Mechanistic features of the activation were elucidated by model studies of the reaction of bis(2-cyanoethyl)diisopropylphosphoroamidite with benzyl alcohol. The importance of the initial protonation stage and formation of an intermediate P(III)-2,4-dinitrophenyl ester were clearly demonstrated by 31 P NMR spectroscopy and independent synthesis. New phosphitylating reagents containing the 2,4-dinitrophenoxy group do not require any activation.