133471-17-7Relevant academic research and scientific papers
Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization
Hersh, William H.
supporting information, p. 184 - 191 (2015/02/19)
The reaction of the diamidite, (iPr2N)2PH, with acyl chlorides proceeds with the loss of HCl to give the corresponding acyl diamidites, RC(O)P(N(iPr)2)2 (R = Me (7), Ph (9)), without the intervention of sodium to give a phosphorus anion. The structure of 9 was confirmed by single-crystal X-ray diffraction. The coupling of the diamidites 7 and 9 with 5'-O-DMTr-thymidine was carried out with N-methylimidazolium triflate as the activator to give the monoamidites 3'-O-(P(N(iPr)2)C(O)R)-5'-O-DMTr-thymidine, and further coupling with 3'-O-(tert-butyldimethylsilyl)thymidine was carried out with activation by pyridinium trifluoroacetate/N-methylimidazole. The new dinucleoside acylphosphonites could be further oxidized, hydrolyzed to the H-phosphonates, and sulfurized to give the known mixture of diastereomeric phosphorothioates. The goal of this work was the measurement of the barrier to inversion of the acylphosphonites, which was expected to be low by analogy to the low barrier found in acylphosphines. However, the barrier was found to be high as no epimerization was detected up to 150 °C, and consistent with this, density functional theory calculations give an inversion barrier of over 40 kcal/mol.
Sulfurization of dinucleoside phosphite triesters with chiral disulfides
Mukhlall, Joshua A.,Hersh, William H.
experimental part, p. 706 - 725 (2012/01/03)
Sixteen chiral analogues of phenylacetyl disulfide (PADS) and 5-methyl-3H-1,2,4-dithiazol-3-one (MEDITH) were used to sulfurize five dithymidine phosphite triesters, each incorporating a β-cyanoethoxy or siloxy group. Each mixture of SP:RP phosphite triester diastereomers was combined with approximately one fourth of an equivalent of each of the sulfurizing reagents, and the RPS:SPS diastereomer ratios of the resulting phosphite sulfides or phosphorothioates were determined by reverse-phase HPLC. Diastereoselectivities and corresponding diastereomeric excess (de) values were calculated by correcting for the starting triester diastereomer ratios. The highest de values for RPS and SPS phosphorothioates were 14.7% and 7.9%, respectively, both using MEDITH analogues. Copyright Taylor and Francis Group, LLC.
Synthesis of oligodeoxyribonucleotides containing hydroxymethylphosphonate bonds in the phosphoramidite method and their hybridization properties
Ohkubo, Akihiro,Aoki, Katsufumi,Ezawa, Yusuke,Sato, Yuichi,Taguchi, Haruhiko,Seio, Kohji,Sekine, Mitsuo
, p. 8953 - 8957 (2007/10/03)
A set of diastereomeric TpT phosphoramidite building blocks, 1-f and 1-s, containing an alkaline-labile hydroxymethylphosphonate (HMP) linkage were synthesized. Dodecadeoxynucleotides incorporating the HMP bond were also synthesized by use of each stereoc
