- Solid-phase synthesis of backbone-modified DNA analogs by the boranophosphotriester method using new protecting groups for nucleobases
-
Backbone-modified DNA analogs were synthesized in good yields by the boranophosphotriester method on a solid support. The oligodeoxyribonucleoside boranophosphates, protected with 2-(azidomethyl)benzoyl groups for nucleobases, were converted into DNA and its backbone-modified analogs via the corresponding H-phosphonate intermediates. A new protecting group for the O6 position of 2′-deoxyguanosine, 4-azidobenzyl (ABn) group, was also developed. The ABn group can be quickly removed by treatment with MePPh2 and H2O in the presence of 2-mercaptoethanol.
- Kawanaka, Toshihide,Shimizu, Mamoru,Shintani, Noriko,Wada, Takeshi
-
scheme or table
p. 3783 - 3786
(2009/04/06)
-
- Facile synthesis of oligodeoxyribonucleotides via the phosphoramidite method without nucleoside base protection
-
A facile synthesis of oligodeoxyribonucleotides via the phosphoramidite approach without base protection of the building blocks has been developed; it relies on the use of imidazolium triflate as a promoter for the condensation of a nucleoside phosphoramidite and a nucleoside. In the solution phase, the condensation is accomplished in a highly O-selective manner by using equimolar amounts of an N-free nucleoside phosphoramidite and an N-unblocked nucleoside to give, after oxidation with bis(trimethylsilyl)peroxide or with tert-butyl hydroperoxide, a dinucleoside phosphate in > 95% yield. In the solid-phase synthesis, which requires an excess amount of the phosphoramidite for the condensation, deoxyadenosine and deoxycytidine undergo N-phosphitylation to some extent. The undesired product, however, can be converted to the N-free derivative by brief treatment with benzimidazolium triflate in methanol. Thus the overall process allows the chemoselective formation of internucleotide linkage. The oligomers prepared by this N-unprotected solid-phase approach include (5')GTCACGACGTTGTAAAACGAC(3') (21mer), (5')CAGGAAACAG-CTATGACCATG(3') (21mer), (5')CAAGTTGATGAACAATACTTCATACCTAAACT(3') (32mer), and (5')TATGGGCCTTTGATAGGATGCTCACCGAGCAAAACCAAGAACAA-CCAGGAGATTTATT(3') (60mer), which are provided in excellent quality. PCR amplification of DNAs using the crude 21mers as primers is also demonstrated.
- Hayakawa, Yoshihiro,Kataoka, Masanori
-
p. 12395 - 12401
(2007/10/03)
-
- The 2-(acetoxymethyl)benzoyl (AMB) group as a new base-protecting group, designed for the protection of (phosphate) modified oligonucleotides
-
The 2-(acetoxymethyl)benzoyl (AMB) group is a new base-protecting group that facilitates the synthesis of labile, modified nucleotides, since it can be rapidly cleaved under mild basic conditions.
- Kuijpers,Huskens,Van Boeckel
-
p. 6729 - 6732
(2007/10/02)
-
- O-2,4-DICHLOROPHENYL S-METHYL PHOSPHOROCHLORIDOTHIOATE: A VERSATILE AGENT IN THE FORMATION OF THE 3'-5' INTERNUCLEOTIDIC LINKAGE BY THE PHOSPHOTRIESTER APPROACH TO OLIGONUCLEOTIDE SYNTHESIS
-
O-2,4-dichlorophenyl S-methyl phosphorochloridothioate can be used as a phosphorylating agent in the formation of (3'-5') dinucleoside phosphates and phosphorothioates.The former have beeen obtained by removal of the methylthio function from the protected
- Caruso, Pier Bartolomeo,Sindona, Giovanni,Liguori, Angelo,Uccella, Nicola
-
p. 253 - 256
(2007/10/02)
-