In situactivation of bis-dialkylaminophosphines—a new method for synthesizing deoxyoligonucleotides on polymer supports

Abstract

Deoxynucleoside phosphoramidites can be prepared in good yield from deoxynucleosides, bis-dialkylaminophosphines, and the corresponding dialkylamine hydrotetrazolide or tetrazole as catalysts. These phosphoramidites generated in situ lead to the direct synthesis of deoxyoligonucleotides on polymer supports. INTRODUCTIONThe current phosphite triester methodology for deoxyoligonucleotide synthesis requires the condensation of deoxynucleoside phosphoramidites 7a-d or 8a-d, activated by tetrazole, with the 5'-hydroxyl group of a deoxynucleoside or deoxyoligonucleotide attached covalently to a polymer support (1-4). Although these phosphoramidites can be prepared by existing methods (5,6) from the appropriately protected deoxynucleosides la-d, the chlorophosphines 2 and 3 used in forming 7a-d and 8a-d, respectively, are difficult to prepare and easily react with trace amounts of water. Moreover, the high reactivity of 2 and 3 and the concomitant production of insoluble amine hydrochloride salts preclude their use for any strategy involving the in situ generation of deoxynucleoside phosphoramidites for deoxyoligonucleotide synthesis on solid supports (7). Because of our interest in the latter approach, we were prompted to investigate the relative stability and reactivity of the aminophosphines 4, 5, and 6 towards phosphodiester formation. We wish to report that the phosphoramidites 7a-d and 8a-d can be prepared in good yields by the reaction of suitably protected deoxynucleosides la-d and bis-dialkylaminophosphines 4 or 6 using amine salts 9 and 10, respectively, as catalysts. This method was applied to a

The influence of exocyclic substituents of purine bases on DNA curvature.

“…10), N2-benzoyl-2-aminopurine 2'-deoxyribonucleoside (dn2R; L.M., unpublished data), and N6-benzoyl-N2-isobutyryl-2,6-diaminopurine 2'-deoxyribonucleoside (dn26R; ref. 11) were protected at the 5'-position by reaction with 9-chloro-9-phenylxanthene (12) and subsequently allowed to react at the 3' position with 2-cyanoethyl-N,N,N',N'-tetraisopropyl phosphorodiamidite (13). Structure and purity of these nucleoside phosphoramidite derivatives were confirmed by 1H-and 31P-NMR spectroscopy.…”

Effective method for obtaining long nucleotide chains on partially complementary templates Processed bovine γ‐interferon gene obtained from human γ‐interferon gene

“…Oligodeoxyribonucleotides were synthesized with semiautomatic synthesizer, designed in our laboratory, using 5 '-dimethoxytrityl-O-nucleoside-3' -phosphoramidites as monomers [3,4].…”

Hybridization and cellular uptake properties of lipophilic oligonucleotide-dendrimer conjugates

“…The corresponding 3′-oligonucleotidedendrimer conjugate 14 was assembled using the appropriate solid support 11 and standard phosphoramidite chemistry. 19 Conjugates 15 to 18 contained a 5′-fluoresceine label, which was attached post-synthetically, through a 5'-aminolinker. After cleavage from the solid support and deprotection with aqueous ammonium hydroxide (55°C, overnight), the oligonucleotides were purified by reverse phase HPLC.…”