A convenient route to synthesize N²-(isobutyryl)-9-(carboxymethyl)guanine for aeg-PNA backbone

References

• (a) Meng, H.-M.; Liu, H.; Kuai, H.; Peng, R.; Mo, L.; Zhang, X.-B. Aptamer-integrated DNA nanostructures for biosensing, bioimaging and cancer therapy. Chem. Soc. Rev. 2016, 45, 2583–2602.
   PubMed Web of Science ®Google Scholar
  (b) Keyser, U. F. Enhancing nanopore sensing with DNA nanotechnology. Nature Nanotech. 2016, 11, 106–108.
   PubMed Web of Science ®Google Scholar
• (a) Nielsen, P. E.; Haaima, G. Peptide nucleic acid (PNA). A DNA mimic with a pseudopeptide backbone. Chem. Soc. Rev. 1997, 26, 73–78.
   Web of Science ®Google Scholar
  (b) Nielsen, P. E. Peptide Nucleic Acid. A Molecule with Two Identities. Acc. Chem. Res. 1999, 32, 624–630.
   Web of Science ®Google Scholar
• Egholm, M.; Buchardt, O.; Christensen, L.; Behrens, C.; Freier, S. M.; Driver, D. A.; Berg, R. H.; Kim, S. K.; Norden, B.; Nielsen, P. E. PNA Hybridizes to Complementary Oligonucleotides Obeying the Watson–Crick Hydrogen-Bonding Rules. Nature 1993, 365, 566–568. DOI: 10.1038/365566a0.
   PubMed Web of Science ®Google Scholar
• (a) Egholm, M.; Christensen, L.; Dueholm, K. L.; Buchardt, O.; Coull, J.; Nielsen, P. E. Nucleic Acids Res. 1995, 23, 217–222.
   PubMed Web of Science ®Google Scholar
  (b) Datta, B.; Schmitt, C.; Armitage, B. A. J. Am. Chem. Soc. 2003, 125, 4111–4118.
   PubMed Web of Science ®Google Scholar
  (c) Datta, B.; Bier, M. E.; Roy, S.; Armitage, B. A. J. Am. Chem. Soc. 2005, 127, 4199–4207.
   PubMed Web of Science ®Google Scholar
  (d) Marin, V. L.; Armitage, B. A. J. Am. Chem. Soc. 2005, 127, 8032–8033.
   PubMed Web of Science ®Google Scholar
• D’Costa, M.; Kumar, V. A.; Ganesh, K. N. N7-Guanine as a C + Mimic in Hairpin Aeg/aepPNA–DNA Triplex: Probing Binding Selectivity by UV-Tm and Kinetics by Fluorescence-Based Strand-Invasion Assay. J. Org. Chem. 2003, 68, 4439–4445. DOI: 10.1021/jo034048h.
   PubMed Web of Science ®Google Scholar
• Englund, E. A.; Xu, Q.; Witschi, M. A.; Appella, D. H. PNA-DNA Duplexes, Triplexes, and Quadruplexes Are Stabilized with Trans-Cyclopentane Units. J. Am. Chem. Soc. 2006, 128, 16456–16457. DOI: 10.1021/ja064317w.
   PubMed Web of Science ®Google Scholar
• Uhlmann, E.; Peyman, A.; Breipohl, G.; Will, D. W . PNA: Synthetic Polyamide Nucleic Acids with Unusual Binding Properties. Angew. Chem. Int. Ed. Engl. 1998, 37, 2796–2823. DOI: 10.1002/(SICI)1521-3773(19981102)37:20<2796::AID-ANIE2796>3.0.CO;2-K.
   PubMed Web of Science ®Google Scholar
• Breipohl, G.; Will, D. W.; Peyman, A.; Uhlmann, E. Novel Synthetic Routes to PNA Monomers and PNA–DNA Linker Molecules. Tetrahedron 1997, 53, 14671–14686. DOI: 10.1016/S0040-4020(97)01044-2.
   Web of Science ®Google Scholar
• Zou, R.; Robins, M. High-Yield Regioselective Synthesis of 9-Glycosyl Guanine Nucleosides and Analogues via Coupling with 2-N-Acetyl-6-O-Diphenylcarbamoylguanine. Can. J. Chem. 1987, 65, 1436–1437. DOI: 10.1139/v87-243.
   Web of Science ®Google Scholar
• Liu, Z.-C.; Shin, D.-S.; Lee, K.-T.; Jun, B.-H.; Kim, Y.-K.; Lee, Y.-S. Synthesis of Photolabile o-Nitroveratryloxycarbonyl (NVOC) Protected Peptide Nucleic Acid Monomers. Tetrahedron 2005, 61, 7967–7973. DOI: 10.1016/j.tet.2005.06.002.
   Web of Science ®Google Scholar
• Timar, Z.; Kovacs, L.; Kovacs, G.; Schmel, Z. Fmoc / Acyl protecting groups in the synthesis of polyamide (peptide) nucleic acid monomers. Perkin 2000, 1, 19–26.
   Google Scholar
• Harnden, M. R.; Jarvest, R. L.; Bacon, T. H.; Boyd, M. R. Synthesis and Antiviral Activity of 9-[4-Hydroxy-3-(Hydroxymethyl)but-1-yl]Purines. J. Med. Chem. 1987, 30, 1636–1642. DOI: 10.1021/jm00392a020.
   PubMed Web of Science ®Google Scholar
• Will, D. W.; Breipohl, G.; Langner, D.; Knolle, J.; Uhlmann, E. The Synthesis of Polyamide Nucleic Acids Using a Novel Monomethoxytrityl Protecting-Group Strategy. Tetrahedron 1995, 51, 12069–12082. DOI: 10.1016/0040-4020(95)00766-2.
   Web of Science ®Google Scholar
• Jenny, T. F.; Schneider, K. C.; Benner, S. A. N2-Isobutyryl-O6-[2-(p-nitrophenyl)ethyl]guanine: a new building block for the efficient synthesis of carbocyclic guanosine analogs. Nucleosides Nucleotides 1992, 11, 1257–1261. DOI: 10.1080/07328319208018340.
   Web of Science ®Google Scholar
• (a) Aldrian-Herrada, G.; Rabie, A.; Wintersteiger, R.; Brugidou, J. Solid-phase synthesis of peptide nucleic acid (PNA) monomers and their oligomerization using disulfide anchoring linkers. J. Peptide Sci. 1998, 4, 266–281.
   PubMed Web of Science ®Google Scholar
  (b) Heuer-Jungemann, A; Howarth, N. M.; JaAfaru, S. C.; Rosair, G. M. Development of a convenient route for the preparation of the N2-Cbz-protected guaninyl synthon required for Boc-mediated PNA synthesis. Tetrahedron Lett. 2013, 54, 6275–6278.
   Web of Science ®Google Scholar
  (c) Sato, N.; Tsuji, G.; Sasaki, Y.; Usami, A.; Moki, T.; Onizuka, K.; Yamada, K.; Nagatsugi, F. A new strategy for site-specific alkylation of DNA using oligonucleotides containing an abasic site and alkylating probes. Chem. Commun. 2015, 51, 14885–14888.
   PubMed Web of Science ®Google Scholar
• Heuer-Jungemann, A.; Howarth, N. M.; Ja’Afaru, S. C.; Rosair, G. M. Development of a Convenient Route for the Preparation of the N2-Cbz-Protected Guaninyl Synthon Required for Boc-Mediated PNA Synthesis. Tetrahedron Lett. 2013, 54, 6275–6278. DOI: 10.1016/j.tetlet.2013.09.034.
   Web of Science ®Google Scholar
• Nagapradeep, N.; Verma, S . Characterization of an Unprecedented Organomercury Adduct via Hg(II)-Mediated Cyclization of N9-Propargylguanine. Chem. Commun. (Camb.) 2011, 47, 1755–1757. DOI: 10.1039/c0cc03123b.
   PubMed Web of Science ®Google Scholar
• (a) Egholm, M.; Buchardt, O.; Nielsen, P. E.; Berg, R. H. Peptide nucleic acids (PNA). Oligonucleotide analogs with an achiral peptide backbone. J. Am. Chem. Soc. 1992, 114, 1895–1897.
   Web of Science ®Google Scholar
  (b) Egholm, M.; Nielsen, P. E.; Buchardt, O.; Berg, R. H. Recognition of guanine and adenine in DNA by cytosine and thymine containing peptide nucleic acids (PNA). J. Am. Chem. Soc. 1992, 114, 9677–9678. DOI: 10.1021/ja00050a068.
   Web of Science ®Google Scholar
• Debaene, F.; Winssinger, N. Azidopeptide Nucleic Acid. An Alternative Strategy for Solid-Phase Peptide Nucleic Acid (PNA) Synthesis. Org. Lett. 2003, 5, 4445–4447. DOI: 10.1021/ol0358408.
   PubMed Web of Science ®Google Scholar
• (a) Neuner, P.; Monaci, P. New Fmoc Pseudoisocytosine Monomer for the Synthesis of a Bis-PNA Molecule by Automated Solid-Phase Fmoc Chemistry. Bioconjugate Chem. 2002, 13, 676–678.
   PubMed Web of Science ®Google Scholar
  (b) Porcheddu, A.; Giacomelli, G.; Piredda, I.; Carta, M.; Nieddu, G. A practical and efficient approach to PNA monomers compatible with Fmoc-mediated solid-phase synthesis protocols. Eur. J. Org. Chem. 2008, 5786–5797.
   Web of Science ®Google Scholar
  (c) Avitabile, C.; Moggio, L.; D'Andrea, L. D.; Pedone, C.; Romanelli, A. Development of an efficient and low-cost protocol for the manual PNA synthesis by Fmoc chemistry. Tetrahedron Lett. 2010, 51, 3716–3718.
   Web of Science ®Google Scholar
  (d) Behrendt, R.; White, P.; Offer, J. Advances in Fmoc solid-phase peptide synthesis. J. Pept. Sci. 2016, 22, 4–27.
   PubMed Web of Science ®Google Scholar
  (e) Luna, O. F.; Gomez, J.; Cardenas, C.; Albericio, F.; Marshall, S. H.; Guzman, F. Deprotection reagents in Fmoc solid phase peptide synthesis: Moving away from piperidine? Molecules 2016, 21, 1542.
   Google Scholar
  (f) Sugiyama, T.; Hasegawa, G.; Niikura, C.; Kuwata, K.; Imamura, Y.; Demizu, Y.; Kurihara, M.; Kittaka, A. PNA monomers fully compatible with standard Fmoc-based solid-phase synthesis of pseudocomplementary PNA. Bioorg. Med. Chem. Lett. 2017, 27, 3337–3341.
   PubMed Web of Science ®Google Scholar
• Qu, G.; Zhang, Z.; Guo, H.; Geng, M.; Xia, R. Microwave-Promoted Facile and Efficient Preparation of N-(Alkoxycarbonylmethyl) Nucleobases-Building Blocks for Peptide Nucleic Acids. Molecules 2007, 12, 543–551. DOI: 10.3390/12030543.
   PubMed Web of Science ®Google Scholar
• Cella, J. A.; Bacon, S. W. Preparation of Dialkyl Carbonates via the Phase-Transfer-Catalyzed Alkylation of Alkali Metal Carbonate and Bicarbonate Salts. J. Org. Chem. 1984, 49, 1122–1125. DOI: 10.1021/jo00180a033.
   Web of Science ®Google Scholar
• (a) Dijkstra, G.; Kruizinga, W. H.; Kellogg, R. M. An assessment of the causes of the “cesium effect”. J. Org. Chem. 1987, 52, 4230–4234.
   Web of Science ®Google Scholar
  (b) Galli, C. “Cesium ion effect” and macrocyclization. A critical review. Org. Prep. Proced. Int. 1992, 24, 285–307.
   Web of Science ®Google Scholar
• Flessner, T.; Doye, S. Cesium Carbonate: A Powerful Inorganic Base in Organic Synthesis. J. Prakt. Chem. 1999, 341, 186–190. DOI: 10.1002/(SICI)1521-3897(199902)341:2<186::AID-PRAC186>3.0.CO;2-6.
   Google Scholar