O-Selective Condensation Using P−N Bond Cleavage in RNA Synthesis without Base Protection

Abstract

In RNA synthesis without base protection, a new method for O-selective condensation with more than 99% selectivity was developed by 6-nitro-HOBt-mediated cleavage of undesired P(III)-N bonds on nucleobase moieties. Moreover, we for the first time succeeded in synthesizing oligoRNAs without base protection.

Regioselective phosphorylation of myo-inositol with BINOL-derived phosphoramidites and its application for protozoan lysophosphatidylinositol

“…Phosphorylation using (R)-BINOL-phosphoryl chloride (11) 25 with several myo-inositol derivatives under various reaction conditions obtained unsatisfactory results; e.g., the conditions shown in Table 1 (entry 1) obtained no selectivity. 27 The reaction was faster than with tetrazole, but the selectivity was somewhat decreased (1-P : 3-P = 67 : 33) (entry 3). When the reaction was continued for more than one day, the 1,3-bisphosphorylated compound quantity was gradually increased, which is shown in entry 2.…”

Site-Specific Synthesis of N4-Acetylcytidine in RNA Reveals Physiological Duplex Stabilization

“…The synthesis of protected D used an adaptation of a previously reported method (Figure S6), 38 while the Gm monomer was readily obtained via nucleobase deprotection of commercial starting material in a single step. 39 These materials were then applied in combination with the previously described building blocks using the optimized solid-phase protocol to synthesize tRNA Ser D-arm models containing either C or ac4C at the C12 position.…”

Nucleotides and Nucleic Acids; Oligo- and Polynucleotides

“…Use of 6-nitroHOBt has been shown to increase the O to N phosphitylation by more than 95%. 4 Use of the new 3 0 -O-silyl loading nucleosides (2) for DNA synthesis has been reported to lead to higher loading of nucleosides on to CPG, with loading of up to 17-29 mmol/g on amino-modified CPG reported. Oligonucleotides are removed from support using 0.2 M Et 3 N d HF at room temperature in 4 h. 5 4-Oxoheptanedioic acid has also been used as a linker between CPG and the first nucleoside, which is removed by treatment with hydrazinium acetate allowing for orthogonal chemistry involving removal of other base protecting groups on solid support.…”

“…One of the adducts formed by mitomycin C with dG has been synthesised by a post-synthetic step using triamino mitosene. 247 The solution structure of a duplex containing an N2-guanine adduct with a pyrrolo[2,1-c] [1,4]benzodiazepine, such as is found with anthramycin or tomaymycin has been reported. 248 Of the modifications at C6 of guanine most are connected with O 6 -alkyl derivatives which are derived from exposure to alkylating agents, such as N-methyl-N-nitrosourea, and are mutagenic lesions.…”

“…807 A solution structure of a duplex containing the mutagenic lesion 1,N2-etheno-dG has been determined that shows a minimally disturbed structure with the lesion stacked into the duplex. Other guanine lesions include the related 1,N2-adduct derived from trans-4-hydroxynonenal, 240 and the N2-((2-naphthyl)-pyrrolo[2,1-c] [1,4]benzodiazepine). 248 Two structures are reported for duplexes containing an abasic site 808 or its tetrahydrofuran stable analogue.…”