Triethylsilane in the presence of dichloroacetic acid in dichloromethane is an efficient DMT cation scavenger during the synthesis of deoxyribonucleotide phosphorothioates and leads to increased overall yields.
Month: December 2019
New phosphorylating reagents Misoprostol fedex 1 and Svyetlahorsk 2 were prepared in three steps from 4-hydroxybenzaldehyde. They showed good efficiency in the solid phase synthesis of 5′-phosphate monoester nucleosides. End-phosphate DNA sequence synthesis demonstrated the efficiency of the new reagents ( http://centralenfieldclc.org.uk/ENSEN/slider1 1 and 2) according to the general procedure of automated DNA synthesis. The oxidation of P(III) to P(V) and the removal of benzyl protecting groups were achieved in a single step by treatment with a 0.02 M I2/pyridine/H2O solution. Due to this one-pot treatment, it is possible to use the phosphorylating reagents (1 and 2) for the synthesis of base-sensitive ODNs. The reagents 1 and 2 are unique among phosphorylating reagents.
A versatile reagent for the synthesis of 5′-phosphorylated, 5′-thiophosphorylated or 5′-phosphoramidate-conjugated oligonucleotides
We report the synthesis of a new phosphorylating reagent that is easily accessible and allows not only the chemical synthesis of 5′-phosphorylated and 5′-thiophosphorylated oligonucleotides but also the 5′-conjugation through a phosphoramidate linkage. 5′-Amino-linker and 5′-alkyne oligonucleotides were obtained and the latter was conjugated by a 1,3-dipolar cycloaddition (click chemistry) with a galactosylated azide derivative to afford 5′-galactosyl oligonucleotide with high efficiency.
Two novel phosphoramidite building blocks and a solid support that allow an efficient solid-phase phosphorylation or thiophosphorylation of synthetic oligonucleotides were developed. The utility of these synthetic tools was demonstrated in the preparation of 5′- or 3′-thiophosphorylated oligonucleotides, which were subsequently labeled at the termini with fluorescent reporters.