1
|
Osawa T, Akino T, Obika S. Synthesis, Duplex-Forming Ability, and Enzymatic Stability of Oligonucleotides Modified with Amide-Linked Dinucleotides Containing a 3',4'-Tetrahydropyran-Bridged Nucleic Acid. J Org Chem 2024; 89:269-280. [PMID: 38064209 DOI: 10.1021/acs.joc.3c02019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Replacement of a phosphodiester linkage with an amide linkage can improve the binding affinity of oligonucleotides to complementary RNA and their stability toward nucleases. In addition, restricting the conformation of the sugar moiety and the phosphate backbone in oligonucleotides effectively improves duplex stability. In this study, we designed amide-linked dinucleotides containing a 3',4'-tetrahydropyran-bridged nucleic acid (3',4'-tpBNA) with a constrained sugar conformation as well as a torsion angle ε. Phosphoramidites of the designed dinucleotides were synthesized and incorporated into oligonucleotides. Conformational analysis of the synthesized dinucleotides showed that the sugar conformation of the S-isomer of the amide-linked dinucleotide containing 3',4'-tpBNA was N-type, which has the same conformation as that of the RNA duplex, while that of another R-isomer was S-type. Tm analysis indicated that the oligonucleotides containing the synthesized S-isomer showed RNA-selective hybridizing ability, although their duplex-forming ability was slightly inferior to that of natural oligonucleotides. Interestingly, the stability of the oligonucleotides toward endonucleases was significantly improved by modification with the two types of amide-linked dinucleotides developed in this study.
Collapse
Affiliation(s)
- Takashi Osawa
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Taiki Akino
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Satoshi Obika
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
- Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Yamadaoka 1-3, Suita, Osaka 565-0871, Japan
| |
Collapse
|
2
|
Chardet C, Payrastre C, Gerland B, Escudier JM. Convertible and Constrained Nucleotides: The 2'-Deoxyribose 5'-C-Functionalization Approach, a French Touch. Molecules 2021; 26:5925. [PMID: 34641475 PMCID: PMC8512084 DOI: 10.3390/molecules26195925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 09/21/2021] [Accepted: 09/27/2021] [Indexed: 11/17/2022] Open
Abstract
Many strategies have been developed to modulate the biological or biotechnical properties of oligonucleotides by introducing new chemical functionalities or by enhancing their affinity and specificity while restricting their conformational space. Among them, we review our approach consisting of modifications of the 5'-C-position of the nucleoside sugar. This allows the introduction of an additional chemical handle at any position on the nucleotide chain without disturbing the Watson-Crick base-pairing. We show that 5'-C bromo or propargyl convertible nucleotides (CvN) are accessible in pure diastereoisomeric form, either for nucleophilic displacement or for CuAAC conjugation. Alternatively, the 5'-carbon can be connected in a stereo-controlled manner to the phosphate moiety of the nucleotide chain to generate conformationally constrained nucleotides (CNA). These allow the precise control of the sugar/phosphate backbone torsional angles. The consequent modulation of the nucleic acid shape induces outstanding stabilization properties of duplex or hairpin structures in accordance with the preorganization concept. Some biological applications of these distorted oligonucleotides are also described. Effectively, the convertible and the constrained approaches have been merged to create constrained and convertible nucleotides (C2NA) providing unique tools to functionalize and stabilize nucleic acids.
Collapse
Affiliation(s)
| | | | - Béatrice Gerland
- Laboratoire de Synthèse et Physico-Chimie de Molécules d′Intérêt Biologique, UMR CNRS 5068, Université Paul Sabatier, 118 Route de Narbonne, CEDEX 9, 31062 Toulouse, France; (C.C.); (C.P.)
| | - Jean-Marc Escudier
- Laboratoire de Synthèse et Physico-Chimie de Molécules d′Intérêt Biologique, UMR CNRS 5068, Université Paul Sabatier, 118 Route de Narbonne, CEDEX 9, 31062 Toulouse, France; (C.C.); (C.P.)
| |
Collapse
|
3
|
Escudier JM, Payrastre C, Gerland B, Tarrat N. Convertible and conformationally constrained nucleic acids (C 2NAs). Org Biomol Chem 2019; 17:6386-6397. [PMID: 31210235 DOI: 10.1039/c9ob01150a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We introduce the concept of Convertible and Constrained Nucleic Acids (C2NAs). By means of the synthesis of a stereocontrolled N-propargyl dioxo-1,3,2-oxaza-phosphorinane as an internucleotidic linkage, the torsional angles α and β can adopt either the canonical (g-, t) set of values able to increase DNA duplex stability or the non-canonical (g+, t) set that stabilized the hairpin structure when installed within the loop moiety. With an appended propargyl function on the nitrogen atom of the six-membered ring, the copper catalysed Huisgen's cycloaddition (CuAAC click chemistry) allows for the introduction of new functionalities at any location on the nucleic acid chain while maintaining the properties brought by the geometrical constraint and the neutral internucleotidic linkage.
Collapse
Affiliation(s)
- Jean-Marc Escudier
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, UMR CNRS 5068, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse, France.
| | - Corinne Payrastre
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, UMR CNRS 5068, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse, France.
| | - Béatrice Gerland
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, UMR CNRS 5068, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse, France.
| | - Nathalie Tarrat
- CEMES, Université de Toulouse, CNRS, 29 rue Jeanne Marvig, Toulouse 31055, France
| |
Collapse
|
4
|
Gerland B, Addamiano C, Renard BL, Payrastre C, Gopaul D, Escudier JM. Thio- and Seleno-Dioxaphosphorinane-Constrained Dinucleotides (D-CNA): Synthesis and Conformational Study. European J Org Chem 2017. [DOI: 10.1002/ejoc.201601568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Béatrice Gerland
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, UMR CNRS 5068; Université Paul Sabatier; 118 route de Narbonne 31062 Toulouse France
| | - Claudia Addamiano
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, UMR CNRS 5068; Université Paul Sabatier; 118 route de Narbonne 31062 Toulouse France
| | - Brice-Loïc Renard
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, UMR CNRS 5068; Université Paul Sabatier; 118 route de Narbonne 31062 Toulouse France
| | - Corinne Payrastre
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, UMR CNRS 5068; Université Paul Sabatier; 118 route de Narbonne 31062 Toulouse France
| | - Deshmukh Gopaul
- Laboratoire de Génomes et Génétique; UMR 3525 Institut Pasteur; 25 rue du Docteur Roux 75015 Paris France
| | - Jean-Marc Escudier
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, UMR CNRS 5068; Université Paul Sabatier; 118 route de Narbonne 31062 Toulouse France
| |
Collapse
|
5
|
Seth PP, Swayze EE. Unnatural Nucleoside Analogs for Antisense Therapy. METHODS AND PRINCIPLES IN MEDICINAL CHEMISTRY 2014. [DOI: 10.1002/9783527676545.ch12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
6
|
Dioxaphosphorinane-constrained nucleic Acid dinucleotides as tools for structural tuning of nucleic acids. J Nucleic Acids 2012; 2012:215876. [PMID: 23150809 PMCID: PMC3488415 DOI: 10.1155/2012/215876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 08/02/2012] [Indexed: 01/03/2023] Open
Abstract
We describe a rational approach devoted to modulate the sugar-phosphate backbone geometry of nucleic acids. Constraints were generated by connecting one oxygen of the phosphate group to a carbon of the sugar moiety. The so-called dioxaphosphorinane rings were introduced at key positions along the sugar-phosphate backbone allowing the control of the six-torsion angles α to ζ defining the polymer structure. The syntheses of all the members of the D-CNA family are described, and we emphasize the effect on secondary structure stabilization of a couple of diastereoisomers of α,β-D-CNA exhibiting wether B-type canonical values or not.
Collapse
|
7
|
Maturano M, Catana DA, Lavedan P, Tarrat N, Saffon N, Payrastre C, Escudier JM. Synthesis and Structural Study of ribo-Dioxaphosphorinane-Constrained Nucleic Acid Dinucleotides (ribo-α,β-D-CNA). European J Org Chem 2011. [DOI: 10.1002/ejoc.201101353] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
8
|
Catana DA, Maturano M, Payrastre C, Lavedan P, Tarrat N, Escudier JM. Synthesis of Phostone-Constrained Nucleic Acid (P-CNA) Dinucleotides Through Intramolecular Arbuzov's Reaction. European J Org Chem 2011. [DOI: 10.1002/ejoc.201101061] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
9
|
Martínez O, Ecochard V, Mahéo S, Gross G, Bodin P, Teissié J, Escudier JM, Paquereau L. α,β-D-constrained nucleic acids are strong terminators of thermostable DNA polymerases in polymerase chain reaction. PLoS One 2011; 6:e25510. [PMID: 21991314 PMCID: PMC3185000 DOI: 10.1371/journal.pone.0025510] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Accepted: 09/07/2011] [Indexed: 11/18/2022] Open
Abstract
(S(C5'), R(P)) α,β-D- Constrained Nucleic Acids (CNA) are dinucleotide building blocks that can feature either B-type torsional angle values or non-canonical values, depending on their 5'C and P absolute stereochemistry. These CNA are modified neither on the nucleobase nor on the sugar structure and therefore represent a new class of nucleotide with specific chemical and structural characteristics. They promote marked bending in a single stranded DNA so as to preorganize it into a loop-like structure, and they have been shown to induce rigidity within oligonucleotides. Following their synthesis, studies performed on CNA have only focused on the constraints that this family of nucleotides introduced into DNA. On the assumption that bending in a DNA template may produce a terminator structure, we investigated whether CNA could be used as a new strong terminator of polymerization in PCR. We therefore assessed the efficiency of CNA as a terminator in PCR, using triethylene glycol phosphate units as a control. Analyses were performed by denaturing gel electrophoresis and several PCR products were further analysed by sequencing. The results showed that the incorporation of only one CNA was always skipped by the polymerases tested. On the other hand, two CNA units always stopped proofreading polymerases, such as Pfu DNA polymerase, as expected for a strong replication terminator. Non-proofreading enzymes, e.g. Taq DNA polymerase, did not recognize this modification as a strong terminator although it was predominantly stopped by this structure. In conclusion, this first functional use of CNA units shows that these modified nucleotides can be used as novel polymerization terminators of proofreading polymerases. Furthermore, our results lead us to propose that CNA and their derivatives could be useful tools for investigating the behaviour of different classes of polymerases.
Collapse
Affiliation(s)
- Olivier Martínez
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche 5089, Centre National de la Recherche Scientifique, Toulouse, France
- Université Paul Sabatier Toulouse III, Faculté des Sciences et d'Ingénierie, Toulouse, France
| | - Vincent Ecochard
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche 5089, Centre National de la Recherche Scientifique, Toulouse, France
- Université Paul Sabatier Toulouse III, Faculté des Sciences et d'Ingénierie, Toulouse, France
| | - Sabrina Mahéo
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche 5089, Centre National de la Recherche Scientifique, Toulouse, France
- Université Paul Sabatier Toulouse III, Faculté des Sciences et d'Ingénierie, Toulouse, France
| | - Grégori Gross
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche 5089, Centre National de la Recherche Scientifique, Toulouse, France
- Université Paul Sabatier Toulouse III, Faculté des Sciences et d'Ingénierie, Toulouse, France
| | - Pierre Bodin
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche 5089, Centre National de la Recherche Scientifique, Toulouse, France
- Université Paul Sabatier Toulouse III, Faculté des Sciences et d'Ingénierie, Toulouse, France
| | - Justin Teissié
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche 5089, Centre National de la Recherche Scientifique, Toulouse, France
- Université Paul Sabatier Toulouse III, Faculté des Sciences et d'Ingénierie, Toulouse, France
| | - Jean-Marc Escudier
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, Unité Mixte de Recherche 5068, Centre National de la Recherche Scientifique, Toulouse , France
| | - Laurent Paquereau
- Institut de Pharmacologie et de Biologie Structurale, Unité Mixte de Recherche 5089, Centre National de la Recherche Scientifique, Toulouse, France
- Université Paul Sabatier Toulouse III, Faculté des Sciences et d'Ingénierie, Toulouse, France
- * E-mail:
| |
Collapse
|
10
|
Boissonnet A, Dupouy C, Millard P, Durrieu MP, Tarrat N, Escudier JM. α,β-D-CNA featuring canonical and noncanonical α/β torsional angles behaviours within oligonucleotides. NEW J CHEM 2011. [DOI: 10.1039/c1nj20086k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
11
|
Brut M, Estève A, Landa G, Dkhissi A, Renvez G, Rouhani MD, Gauchard D. Atomic-scale determination of DNA conformational response to strained furanose: a static mode approach. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.09.083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
12
|
Dupouy C, Millard P, Boissonnet A, Escudier JM. α,β-D-CNA preorganization of unpaired loop moiety stabilizes DNA hairpin. Chem Commun (Camb) 2010; 46:5142-4. [DOI: 10.1039/c0cc00244e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
13
|
Zhou C, Plashkevych O, Chattopadhyaya J. Double sugar and phosphate backbone-constrained nucleotides: synthesis, structure, stability, and their incorporation into oligodeoxynucleotides. J Org Chem 2009; 74:3248-65. [PMID: 19348480 DOI: 10.1021/jo900391n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Two diastereomerically pure carba-LNA dioxaphosphorinane nucleotides [(S(p))- or (R(p))-D(2)-CNA], simultaneously conformationally locked at the sugar and the phosphate backbone, have been designed and synthesized. Structural studies by NMR as well as by ab initio calculations showed that in (S(p))- and (R(p))-D(2)-CNA the following occur: (i) the sugar is locked in extreme North-type conformation with P = 11 degrees and Phi(m) = 54 degrees ; (ii) the six-membered 1,3,2-dioxaphosphorinane ring adopts a half-chair conformation; (iii) the fixed phosphate backbone delta, epsilon, and zeta torsions were found to be delta [gauch(+)], epsilon (cis), zeta [anticlinal(+)] for (S(p))-D(2)-CNA, and delta [gauche(+)], epsilon (cis), zeta [anticlinal(-)] for (R(p))-D(2)-CNA. It has been found that F(-) ion can catalyze the isomerization of pure (S(p))-D(2)-CNA or (R(p))-D(2)-CNA to give an equilibrium mixture (K = 1.94). It turned out that at equilibrium concentration the (S(p))-D(2)-CNA isomer is preferred over the (R(p))-D(2)-CNA isomer by 0.39 kcal/mol. The chemical reactivity of the six-membered dioxaphosphorinane ring in D(2)-CNA was found to be dependent on the internucleotidic phosphate stereochemistry. Thus, both (S(p))- and (R(p))-D(2)-CNA dimers (17a and 17b) were very labile toward nucleophile attack in concentrated aqueous ammonia [t(1/2) = 12 and 6 min, respectively] to give carba-LNA-6',5'-phosphodiester (21) approximately 70-90%, carba-LNA-3',5'-phosphodiester (22) approximately 10%, and carba-LNA-6',3'-phosphodiester (23) <10%. In contrast, the (S(p))-D(2)-CNA was about 2 times more stable than (R(p))-D(2)-CNA under hydrazine hydrate/pyridine/AcOH (pH = 5.6) [t(1/2) = 178 and 99 h, respectively], which was exploited in the deprotection of pure (S(p))-D(2)-CNA-incorporated antisense oligodeoxynucleotides (AON). Thus, after removal of the solid supports from the (S(p))-D(2)-CNA-modified AONs by BDU/MeCN, they were treated with hydrazine hydrate in pyridine/AcOH to give pure AONs in 35-40% yield, which was unequivocally characterized by MALDI-TOF to show that they have an intact six-membered dioxaphosphorinane ring. The effect of pure (S(p))-D(2)-CNA modification in the AONs was estimated by complexing to the complementary RNA and DNA strands by the thermal denaturation studies. This showed that this cyclic phosphotriester modification destabilizes the AON/DNA and AON/RNA duplex by about -6 to -9 degrees C/modification. Treatment of (S(p))-D(2)-CNA-modified AON with concentrated aqueous ammonia gave carba-LNA-6',5'-phosphodiester modified AON ( approximately 80%) plus a small amount of carba-LNA-3',5'-phosphodiester-modified AON ( approximately 20%). It is noteworthy that Carba-LNA-3',5'-phosphodiester modification stabilized the AON/RNA duplex by +4 degrees C/modification (J. Org. Chem. 2009, 74, 118), whereas carba-LNA-6', 5'-phosphodiester modification destabilizes both AON/RNA and AON/DNA significantly (by -10 to -19 degrees C/modification), which, as shown in our comparative CD studies, that the cyclic phosphotriester modified AONs as well as carba-LNA-6',5'-phosphodiester modified AONs are much more weakly stacked than carba-LNA-3',5'-phosphodiester-modified AONs.
Collapse
Affiliation(s)
- Chuanzheng Zhou
- Department of Bioorganic Chemistry, Box 581, ICM, Biomedical Center, Uppsala University, SE-751 23 Uppsala, Sweden
| | | | | |
Collapse
|
14
|
|
15
|
Dupouy C, Iché-Tarrat N, Durrieu MP, Vigroux A, Escudier JM. Alpha,beta-D-CNA induced rigidity within oligonucleotides. Org Biomol Chem 2008; 6:2849-51. [PMID: 18688476 DOI: 10.1039/b809775e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Introduction of alpha,beta-D-CNA featuring canonical values of the torsional angles alpha and beta within oligonucleotides leads to an overall stabilization and improved rigidity of the duplex DNA as demonstrated by UV experiments, circular dichroism and corroborated by molecular dynamics simulations.
Collapse
Affiliation(s)
- Christelle Dupouy
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique UMR 5068 CNRS, Université Paul Sabatier, 31062, Toulouse Cedex 9, France
| | | | | | | | | |
Collapse
|
16
|
Dupouy C, Lavedan P, Escudier JM. Synthesis and Structure of Dinucleotides with S-Type Sugar Puckering and Noncanonical ε and ζ Torsion Angle Combination (ν2,ε,ζ-D-CNA). European J Org Chem 2008. [DOI: 10.1002/ejoc.200701022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
17
|
Dupouy C, Lavedan P, Escudier JM. Synthesis and Structure of Dinucleotides Featuring Canonical and Non-canonical A-Type Duplex α, β and δ Torsion Angle Combinations (LNA/α,β-D-CNA). European J Org Chem 2007. [DOI: 10.1002/ejoc.200700535] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
18
|
Synthesis of spiro ɛ,ζ-D-CNA in xylo configuration featuring noncanonical δ/ɛ/ζ torsion angle combination. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.08.098] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
19
|
Le Clézio I, Dupouy C, Lavedan P, Escudier JM. Synthesis and Structure of an α,β-D-CNA Featuring a Noncanonical α/β Torsion Angle Combination within a Tetranucleotide. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700229] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
20
|
Le Clézio I, Vigroux A, Escudier JM. Diastereoselective and Regioselective Synthesis of Conformationally Restricted Thio-dioxa- and Oxo-oxathiaphosphorinane Dinucleotides Featuring Noncanonical α/β Torsion Angle Combinations (α,β-CNAs). European J Org Chem 2007. [DOI: 10.1002/ejoc.200601030] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|