1
|
Wu B, Seifert NA, Oswald S, Jäger W, Xu Y. Rotational Spectroscopy of the 2,2,3,3,3-Pentafluoropropanol⋅⋅⋅Water Complex: Conformations and Large Amplitude Motions. Chemphyschem 2022; 23:e202200348. [PMID: 35759723 DOI: 10.1002/cphc.202200348] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/24/2022] [Indexed: 11/08/2022]
Abstract
The 2,2,3,3,3-pentafluoropropanol (PFP) monomer can exist in five conformations defined by the CCCO and CCOH dihedral angles: four mirror-imaged pairs (G+g+/G-g-, G+g-/G-g+, G+t/G-t, Tg+/Tg-) and an achiral Tt form. We examined the conformational landscape of the PFP⋅⋅⋅water complex using chirped pulsed Fourier transform microwave spectroscopy and theoretical calculations. Rotational spectra of two PFP⋅⋅⋅water conformers, PFPG+g+⋅⋅⋅WH and PFPTg+⋅⋅⋅WH , and seven deuterated isotopologues of each, were assigned. Tunneling splittings were observed for both conformers and are attributed to the exchange of the bonded and non-bonded hydrogen atoms of water. On the other hand, the tunneling splitting associated with the OH flipping motion in PFPTg+/Tg- appears to be quenched upon hydrogen bonding with water. The large amplitude motions associated with the water subunits were examined in detail to explain the very different magnitudes of the experimental and theoretical permanent electric dipole moment components. The study highlights the challenge in correctly identifying the conformers observed when large amplitude motions are involved. Quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analyses, as well as electrostatic potential (ESP) calculations were carried out to explore the nature of the non-covalent interactions and to appreciate the effects of fluorination.
Collapse
Affiliation(s)
- Bowei Wu
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Nathan A Seifert
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.,Chemistry and Chemical & Biomedical Engineering Department University of New Haven, 300 Boston Post Rd, West Haven, CT, 06516, USA
| | - Sönke Oswald
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.,Institut für Physikalische Chemie, Georg-August-Universität Göttingen, Tammannstraße 6, 37077, Göttingen, Germany
| | - Wolfgang Jäger
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Yunjie Xu
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| |
Collapse
|
2
|
Shoji T, Fukushima K, Menjo T, Yamada Y, Hanasaki T, Kikushima K, Takenaga N, Dohi T. Triflimide-Promoted Nucleophilic C-Arylation of Halopurines to Access N 7-Substituted Purine Biaryls. Chem Pharm Bull (Tokyo) 2021; 69:886-891. [PMID: 34148910 DOI: 10.1248/cpb.c21-00380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Functionalized nucleobases are utilized in a wide range of fields; therefore, the development of new synthesis methods is essential for their continued application. With respect to the C6-arylation of halopurines, which possess a substituent at the N7-position, only a small number of successful cases have been reported, which is predominately a result of large steric hinderance effects. Herein, we report efficient and metal-free C6-arylations and SNAr reactions of N7-substituted chloropurines in aromatic and heteroatom nucleophiles promoted by triflimide (Tf2NH) in fluoroalcohol.
Collapse
Affiliation(s)
| | - Kosuke Fukushima
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University
| | - Takayuki Menjo
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University
| | | | - Tomonori Hanasaki
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University
| | | | | | - Toshifumi Dohi
- College of Pharmaceutical Sciences, Ritsumeikan University
| |
Collapse
|
3
|
Fujita T, Shoji N, Yoshikawa N, Ichikawa J. Helicene synthesis by Brønsted acid-catalyzed cycloaromatization in HFIP [(CF 3) 2CHOH]. Beilstein J Org Chem 2021; 17:396-403. [PMID: 33633807 PMCID: PMC7884880 DOI: 10.3762/bjoc.17.35] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 01/26/2021] [Indexed: 02/01/2023] Open
Abstract
A facile synthesis of carbo- and heterohelicenes was achieved via tandem cycloaromatization of bisacetal precursors, which were readily prepared through C–C bond formation by Suzuki–Miyaura coupling. This cyclization was efficiently realized by a catalytic amount of trifluoromethanesulfonic acid (TfOH) in a cation-stabilizing solvent, 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP), which readily allowed gram-scale syntheses of higher-order helicenes, double helical helicenes, and heterohelicenes.
Collapse
Affiliation(s)
- Takeshi Fujita
- Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| | - Noriaki Shoji
- Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| | - Nao Yoshikawa
- Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| | - Junji Ichikawa
- Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| |
Collapse
|
4
|
Takenaga N, Shoji T, Menjo T, Hirai A, Ueda S, Kikushima K, Hanasaki T, Dohi T. Nucleophilic Arylation of Halopurines Facilitated by Brønsted Acid in Fluoroalcohol. Molecules 2019; 24:E3812. [PMID: 31652675 DOI: 10.3390/molecules24213812] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 10/18/2019] [Accepted: 10/21/2019] [Indexed: 12/01/2022]
Abstract
Various aryl-substituted purine derivatives were synthesized through the direct arylation of halopurines with aromatic compounds, facilitated by the combination of triflic acid and fluoroalcohol. This metal-free method is complementary to conventional coupling reactions using metal catalysts and reagents for the syntheses of aryl-substituted purine analogues.
Collapse
|
5
|
Yao F, Liu Q, Zhang Z, Zhu X. RAFT Polymerization of Styrene and Maleimide in the Presence of Fluoroalcohol: Hydrogen Bonding Effects with Classical Alternating Copolymerization as Reference. Polymers (Basel) 2017; 9:polym9030089. [PMID: 30970767 PMCID: PMC6432049 DOI: 10.3390/polym9030089] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/01/2017] [Indexed: 11/16/2022] Open
Abstract
The impacts of hydrogen bonding on polymerization behavior has been of interest for a long time; however, universality and in-depth understanding are still lacking. For the first time, the effect of hydrogen bonding on the classical alternating-type copolymerization of styrene and maleimide was explored. N-phenylmaleimide (N-PMI)/styrene was chosen as a model monomer pair in the presence of hydrogen bonding donor solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), which interacted with N-PMI via hydrogen bonding. Reversible addition-fragmentation chain transfer polymerization (RAFT) technique was used to guarantee the "living" polymerization and thus the homogeneity of chain compositions. In comparison with the polymerization in nonhydrogen bonding donor solvent (toluene), the copolymerization in HFIP exhibited a high rate and a slight deviation from alternating copolymerization tendency. The reactivity ratios of N-PMI and St were revealed to be 0.078 and 0.068, respectively, while the reactivity ratios in toluene were 0.026 and 0.050. These interesting results were reasonably explained by using computer simulations, wherein the steric repulsion and electron induction by the hydrogen bonding between HFIP and NPMI were revealed. This work first elucidated the hydrogen bonding interaction in the classical alternating-type copolymerization, which will enrich the research on hydrogen bonding-induced polymerizations.
Collapse
Affiliation(s)
- Fangjun Yao
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Qingqing Liu
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Zhengbiao Zhang
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Xiulin Zhu
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| |
Collapse
|