Rapid Esterification of Nucleosides to Solid-Phase Supports for Oligonucleotide Synthesis Using Uronium and Phosphonium Coupling Reagents

Abstract

Nucleosides can be esterified to solid-phase supports using uronium or phosphonium coupling reagents and a coupling additive, such as 1-hydroxybenzotriazole (HOBT), 7-aza-1-hydroxybenzotriazole (HOAT), N-methylimidazole (NMI), or 4-(dimethylamino)pyridine (DMAP). However, DMAP was far superior to other additives and high nucleoside loadings (up to 60 micromol/g) and rapid coupling reactions (< or = 10 min) were possible. Hydroxyl-derivatized CPG was attached to nucleosides with 3'-succinyl or 3'-hydroquinone-O, O'-diacetic acid (HQDA or Q-Linker) carboxyl groups through a primary ester linkage. Alternatively, supports derivatized with succinic acid or the Q-Linker were attached directly to the 3'-OH group of nucleosides through a secondary ester linkage. Uronium reagents (HATU or HBTU) gave the best results with the HQDA linker arm, while the bromophosphonium (BrOP or PyBrOP) reagents were best with the succinyl linker arm. In all cases, the coupling reactions were much faster than previous methods using carbodiimide coupling reagents. The ease and speed of the reaction make this support derivatization procedure suitable for automated in situ couplings on DNA synthesizers.

Molecular Requirements for Duplex Recognition and Cleavage by Eukaryotic RNase III: Discovery of an RNA-dependent DNA Cleavage Activity of Yeast Rnt1p

“…The syntheses were performed on a 1 mmol scale using LCAAcontrolled pore glass solid support (500 Å pore size) that was derivatized with the appropriate protected nucleoside. 49 Assembly of the sequences was carried out according to published protocols. 26,50 Monomer coupling times were ten minutes (RNA) and 120 seconds (DNA).…”

The α‐L‐Threofuranosyl‐(3′→2′)‐oligonucleotide System (‘TNA'): Synthesis and Pairing Properties

“…Such cannot be assumed to be the case. 27 ) This requirement specifically refers to situations where simple-looking structures are in fact complex from a generational point of view. Examples of this kind, specifically relevant in the present context, are the phosphodiester based nucleic acid systems derived from glycerol that had been proposed as possible RNA ancestors [43].…”

Base‐Pairing Systems Related to TNA Containing Phosphoramidate Linkages: Synthesis of Building Blocks and Pairing Properties

“…Thus, treatment of 1a and 1b, and 2a and 2b with chloro(2-cyanoethoxy)(diisopropylamino)phosphine in the presence of H¸nig×s base in CH 2 Cl 2 afforded the phosphoramidites 35a and 35b, and 36a and 36b, respectively, in good yields (87 ± 92%). The CPG solidsupport derivatives were prepared also from 1a and 1b, and 2a and 2b via the 3'-Osuccinate derivative following activation with benzotriazole-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (BOP)/1-methyl-1H-imidazole to couple with the LCAA-CPG support [24]. Subsequent capping gave the suitably derivatized CPG-nucleosides 37a and 37b, and 38a and 38b, respectively.…”

“…1 (2004) 964 23 ) During recrystallization, the entire solid did not go into soln., but this had no influence on the final purity of the product. 24 ) MeOH can be removed by dissolving the solid in pyridine and evaporating to dryness (three times). This procedure was applied to obtain samples for acquiring NMR data.…”