Conceptual Basis of the Selective Activation of Bis(dialkylamino)methoxyphosphines by Weak Acids and Its Application toward the Preparation of Deoxynucleoside Phosphoramidites in Situ

Article abstract of DOI:10.1021/jo00212a003

The concept behind the selective activation of bis(dialkylamino)methoxyphosphines is experimentally examined and subsequently used in the preparation of deoxynucleoside phosphoramidites in situ.These intermediates are most efficiently prepared from the reaction of suitably protected deoxynucleosides with dipyrrolidinomethoxyphosphine in the presence of 4,5-dichloroimidazole using 1-methyl-2-pyrrolidinone as solvent.The purity and efficiency of these monomers are evaluated during the solid-phase synthesis of a 22-unit oligomer.