1
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Faramarzi MS, Shabani M, Fazaeli R. Exploring the Origin of the Anomeric Effects in 2,3-Dihalo-1,4-Diphosphinane-1,4-Diium. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024422110188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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2
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Asano K, Matsubara S. Organocatalytic Access to Tetrasubstituted Chiral Carbons Integrating Functional Groups. CHEM REC 2022:e202200200. [PMID: 36163471 DOI: 10.1002/tcr.202200200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/08/2022] [Indexed: 12/15/2022]
Abstract
Three-dimensional organic structures containing sp3 carbons bearing four non-hydrogen substituents can provide drug-like molecules. Although such complex structures are challenging targets in synthetic organic chemistry, efficient synthetic approaches will open a new chemical space for pharmaceutical candidates. This review provides an account of our recent achievements in developing organocatalytic approaches to attractive molecular platforms based on optically active sp3 carbons integrating four different functional groups. These methodologies include asymmetric cycloetherification and cyanation of multifunctional ketones, both of which take advantage of the mild characteristics of organocatalytic activation. Enzyme-like but non-enzymatic organocatalytic systems can be used to precisely manufacture molecules containing complex chiral structures without substrate specificity problems. In addition, these catalytic systems control not only stereoselectivity but also site-selectivity and do not induce side reactions even from substrates with rich functionality.
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Affiliation(s)
- Keisuke Asano
- Institute for Catalysis, Hokkaido University Sapporo, Hokkaido, 001-0021, Japan
| | - Seijiro Matsubara
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University Kyotodaigaku-Katsura, Nishikyo, Kyoto, 615-8510, Japan
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3
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An Interacting Quantum Atoms (IQA) and Relative Energy Gradient (REG) Analysis of the Anomeric Effect. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27155003. [PMID: 35956954 PMCID: PMC9370807 DOI: 10.3390/molecules27155003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 11/30/2022]
Abstract
The explanation of the anomeric effect in terms of underlying quantum properties is still controversial almost 70 years after its introduction. Here, we use a method called Relative Energy Gradient (REG), which is able to compute chemical insight with a view to explaining the anomeric effect. REG operates on atomic energy contributions generated by the quantum topological energy decomposition Interacting Quantum Atoms (IQA). Based on the case studies of dimethoxymethane and 2-fluorotetrahydropyran, we show that the anomeric effect is electrostatic in nature rather than governed by hyperconjugation.
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4
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Zhao H. Modulating Conformational Preferences by Allylic Strain toward Improved Physical Properties and Binding Interactions. ACS OMEGA 2022; 7:9080-9085. [PMID: 35309473 PMCID: PMC8928487 DOI: 10.1021/acsomega.2c00510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 02/25/2022] [Indexed: 06/09/2023]
Abstract
The preference of the axial over the equatorial orientation of 2-substitutent for both phenyl-1-piperidines and N-acylpiperidines is studied at the M06-2X level of theory. For phenyl-1-piperidines, the axial 2-substituent is modestly favored over the equatorial one. In contrast, the pseudoallylic strain in N-acylpiperidines dictates the axial orientation of 2-substituent with a ΔG up to -3.2 kcal/mol. The calculations agree well with the statistics from both the Cambridge Structural Database of small-molecule organic crystal structures and the Protein Data Bank. The equilibrium between the twist-boat and chair conformations for N-acylpiperidines with a 2-substituent was further investigated. The twist-boat conformation is found to be around 1.5 kcal/mol less favorable. Finally, the three-dimensionality in shape resulting from minimization of the pseudoallylic strain is characterized, and its implication in protein-ligand interactions is briefly reviewed.
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5
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Kawanobe Y, Kuragaki N, Tsubomura T, Yamazaki Y, Kuribara T, Totani K. Mechanistic Study of Silyl‐Assist Effect on 1,2‐
cis
‐α‐Glucosylation. ChemistrySelect 2022. [DOI: 10.1002/slct.202104152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yuichi Kawanobe
- Department of Materials and Life Science Seikei University 3-3-1 Kichijoji-kitamachi Musashino-shi Tokyo 180-8633 Japan
| | - Naoya Kuragaki
- Department of Materials and Life Science Seikei University 3-3-1 Kichijoji-kitamachi Musashino-shi Tokyo 180-8633 Japan
| | - Taro Tsubomura
- Department of Materials and Life Science Seikei University 3-3-1 Kichijoji-kitamachi Musashino-shi Tokyo 180-8633 Japan
| | - Yasuomi Yamazaki
- Department of Materials and Life Science Seikei University 3-3-1 Kichijoji-kitamachi Musashino-shi Tokyo 180-8633 Japan
| | - Taiki Kuribara
- Department of Materials and Life Science Seikei University 3-3-1 Kichijoji-kitamachi Musashino-shi Tokyo 180-8633 Japan
| | - Kiichiro Totani
- Department of Materials and Life Science Seikei University 3-3-1 Kichijoji-kitamachi Musashino-shi Tokyo 180-8633 Japan
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6
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Alabugin IV, Kuhn L, Krivoshchapov NV, Mehaffy P, Medvedev MG. Anomeric effect, hyperconjugation and electrostatics: lessons from complexity in a classic stereoelectronic phenomenon. Chem Soc Rev 2021; 50:10212-10252. [PMID: 34542133 DOI: 10.1039/d1cs00564b] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Understanding the interplay of multiple components (steric, electrostatic, stereoelectronic, dispersive, etc.) that define the overall energy, structure, and reactivity of organic molecules can be a daunting task. The task becomes even more difficult when multiple approaches based on different physical premises disagree in their analysis of a multicomponent molecular system. Herein, we will use a classic conformational "oddity", the anomeric effect, to discuss the value of identifying the key contributors to reactivity that can guide chemical predictions. After providing the background related to the relevant types of hyperconjugation and a brief historic outline of the origins of the anomeric effect, we outline variations of its patterns and provide illustrative examples for the role of the anomeric effect in structure, stability, and spectroscopic properties. We show that the complete hyperconjugative model remains superior in explaining the interplay between structure and reactivity. We will use recent controversies regarding the origin of the anomeric effect to start a deeper discussion relevant to any electronic effect. Why are such questions inherently controversial? How to describe a complex quantum system using a model that is "as simple as possible, but no simpler"? What is a fair test for such a model? Perhaps, instead of asking "who is right and who is wrong?" one should ask "why do we disagree?". Stereoelectronic thinking can reconcile quantum complexity with chemical intuition and build the conceptual bridge between structure and reactivity. Even when many factors contribute to the observed structural and conformational trends, electron delocalization is a dominating force when the electronic demand is high (i.e., bonds are breaking as molecules distort from their equilibrium geometries). In these situations, the role of orbital interactions increases to the extent where they can define reactivity. For example, negative hyperconjugation can unleash the "underutilized" stereoelectronic power of unshared electrons (i.e., the lone pairs) to stabilize a developing positive charge at an anomeric carbon. This analysis paves the way for the broader discussion of the omnipresent importance of negative hyperconjugation in oxygen-containing functional groups. From that point of view, the stereoelectronic component of the anomeric effect plays a unique role in guiding reaction design.
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Affiliation(s)
- Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, USA.
| | - Leah Kuhn
- Department of Chemistry and Biochemistry, Florida State University, USA.
| | - Nikolai V Krivoshchapov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation. .,Lomonosov Moscow State University, Leninskie Gory 1 (3), Moscow, 119991, Russian Federation
| | - Patricia Mehaffy
- Department of Chemistry and Biochemistry, Florida State University, USA.
| | - Michael G Medvedev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation. .,A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova St., 119991 Moscow, Russian Federation
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7
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Asano K. Multipoint Recognition of Molecular Conformations with Organocatalysts for Asymmetric Synthetic Reactions. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20200343] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Keisuke Asano
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyotodaigaku-Katsura, Nishikyo, Kyoto 615-8510, Japan
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8
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Tsipis CA, Bakalbassis EG, Zisopoulou SA, Gallos JK. Probing the anomeric effect and mechanism of isomerization of oxazinane rings by DFT methods. Org Biomol Chem 2021; 19:1066-1082. [PMID: 33427840 DOI: 10.1039/d0ob02453h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mechanistic studies of the thermal amine-promoted isomerization of oxazinane rings by DFT methods showed that the isomerization proceeds through abstraction of the C-3 hydrogen atom by the amine nitrogen atom followed by its re-recruitment from C-3 that helps the oxazinane ring to avoid breaking, leading to the same or an isomeric conformer. Calculations also provided evidence that steric effects are responsible for the breaking of the O-N bond in the transition state of the thermal amine-promoted transformations of oxazinane rings, leading to the transformation of the 6-membered ring to a 5-membered ring. Extensive computational studies of the origin of the anomeric effect in the di-substituted oxazinane rings, bearing the EtO substituent at C-6 and CO2Et at C-3, and a series of analogous tetrahydro-2H-pyran ring conformers, revealed that the conformational preferences in both series of compounds are tuned by the balance of non-covalent (weak vDW, dipole-dipole, electrostatic forces, hydrogen bonding) steric effects and hyperconjugative interactions.
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Affiliation(s)
- Constantinos A Tsipis
- School of Chemistry, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
| | - Evangelos G Bakalbassis
- School of Chemistry, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
| | - Stavroula A Zisopoulou
- School of Chemistry, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
| | - John K Gallos
- School of Chemistry, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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9
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Interpretation of anomeric effect in 2-hydroxytetrahydropyrans based on extensive bond interactions. Tetrahedron 2020. [DOI: 10.1016/j.tet.2019.130919] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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10
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Singh V, Ibnusaud I, Gadre SR, Deshmukh MM. Fragmentation method reveals a wide spectrum of intramolecular hydrogen bond energies in antioxidant natural products. NEW J CHEM 2020. [DOI: 10.1039/d0nj00304b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Very strong and weak IHBs in curcumin.
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Affiliation(s)
- Vijay Singh
- Department of Chemistry
- Dr. Harisingh Gour Vishwavidyalaya (A Central University)
- Sagar
- India
| | - Ibrahim Ibnusaud
- Institute for Intensive Research in Basic Sciences
- Mahatma Gandhi University Campus
- P.O. Kottayam
- India
| | - Shridhar R. Gadre
- Interdisciplinary School of Scientific Computing and Department of Chemistry
- Savitribai Phule Pune University
- Pune 411 007
- India
| | - Milind M. Deshmukh
- Department of Chemistry
- Dr. Harisingh Gour Vishwavidyalaya (A Central University)
- Sagar
- India
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11
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Anomeric effect in pyranose-ring derivatives containing carbon, silicon, and germanium as anomeric centers: an ab initio systematic study. Struct Chem 2019. [DOI: 10.1007/s11224-019-01336-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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12
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Alabugin IV, dos Passos Gomes G, Abdo MA. Hyperconjugation. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2018. [DOI: 10.1002/wcms.1389] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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13
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Fraschetti C, Guarcini L, Zazza C, Mannina L, Circi S, Piccirillo S, Chiavarino B, Filippi A. Real time evolution of unprotected protonated galactosamine probed by IRMPD spectroscopy. Phys Chem Chem Phys 2018. [PMID: 29536991 DOI: 10.1039/c7cp07642h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Conformational characterization of single α- and β-epimers of galactosamine in solution still remains an intriguing task because of their flexibility and ability to interconvert. This difficulty was circumvented by recording several "snapshots" of the epimerization process by means of fast ESI vaporization of a galactosamine·HCl sample solution at different times. Consequently, the so generated gaseous mixtures were spectroscopically investigated and the specific conformational features of both α- and β-epimers were assigned, despite the overlapping of several IR signals. Interestingly, from a comparison with time-resolved 1H-NMR data obtained for the same solutions, the catalyzing effect of the applied ESI technique in the anomerization process clearly emerges. Finally, the experimental data were supported using both the Density Functional Theory (DFT) and Block-Localized Wavefunction (BLW) approaches: the latter method was applied here for the first time for the investigation of charged species.
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Affiliation(s)
- C Fraschetti
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza-Università di Roma, P.le Aldo Moro 5, 00185, Rome, Italy.
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14
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Tomkins P, Müller TE. Enhanced Selectivity in the Hydrogenation of Anilines to Cyclo-aliphatic Primary Amines over Lithium-Modified Ru/CNT Catalysts. ChemCatChem 2018. [DOI: 10.1002/cctc.201701613] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Patrick Tomkins
- Centre for Surface Chemistry and Catalysis, Dept. M2S; K. U. Leuven; Celestijnenlaan 200F post box 2461, 3001 Leuven Belgium
| | - Thomas E. Müller
- Department of Chemistry; RWTH Aachen University; Worringerweg 2 52074 Aachen Germany
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15
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Tavanaei L, Nori-Shargh D. New Insights into the Origin of the cis-Configuration Preferences in 1,2-Dihaloethenes: The Importance of the Bonding Orbital Deviations. Aust J Chem 2018. [DOI: 10.1071/ch17219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The origin of the preferences for the cis-configurations in 1,2-difluoroethene (1), 1,2-dichloroethene (2), and 1,2-dibromoethene (3) were explored by means of the G3MP2, LC-ωPBE and CCSD(T) methods with the 6–311+G** basis set on all atoms, and natural bond orbital interpretation. On the basis of the results obtained, the cis-configurations preferences decrease in going from compound 1 to compound 3. Effectively, the deletions of the hyperconjugative interactions from the Fock matrices of the cis- and trans-configurations of compound 1 lead to the increase of the trans-conformation stability (by ~6.11 kcal mol−1) compared with its corresponding cis-conformation. However, the Pauli exchange-type repulsion difference between the cis- and trans-configurations of compound 1 is in favour of the trans-configuration (by ~6.25 kcal mol−1), revealing that the stabilization energies associated with the hyperconjugative interactions do not compensate the destabilizations associated with the exchange component and dipole-dipole interactions. Importantly, the C=C bond paths in the cis-configuration of compound 1 are bent in essentially the same direction (towards the C–F bonds), leading to an increased overlap and a stronger C–C bond, whereas the C–C bond paths in the trans-configuration are bent in opposite directions. Accordingly, the co-operative stabilizations associated with the bending of the C=C bond paths (towards the C–F bonds) and total hyperconjugative generalized anomeric effect overcome the destabilizations associated with the exchange component and dipole–dipole interactions, leading to the preference of the cis-configuration in compound 1. The deletions of all the donor–acceptor electronic interactions from the Fock matrices of the cis- and trans-configurations of compounds 2 and 3 lead to the increase of the trans-conformation stabilities compared with their corresponding cis-conformations, revealing the determining impacts of the hyperconjugative interactions on the configurational preferences in compounds 2 and 3.
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16
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Buschbeck-Alvarado ME, Hernández-Fernández G, Hernández-Trujillo J, Cortés-Guzmán F, Cuevas G. Charge transfer and electron localization as the origin of the anomeric effect in the O─C─O segment of dimethoxymethane and spiroketals. J PHYS ORG CHEM 2017. [DOI: 10.1002/poc.3793] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | | | | | | | - Gabriel Cuevas
- Instituto de Química; Universidad Nacional Autónoma de México; Ciudad de México Mexico
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17
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Organocatalytic enantio- and diastereoselective cycloetherification via dynamic kinetic resolution of chiral cyanohydrins. Nat Commun 2017; 8:1397. [PMID: 29123080 PMCID: PMC5680189 DOI: 10.1038/s41467-017-01099-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 08/15/2017] [Indexed: 12/04/2022] Open
Abstract
Enantioselective approaches to synthesize six-membered oxacycles with multiple stereogenic centres are in high demand to enable the discovery of new therapeutic agents. Here we present a concise organocatalytic cycloetherification for the highly enantio- and diastereoselective synthesis of tetrahydropyrans involving simultaneous construction of two chiral centres, one of which is fully substituted. This method involves dynamic kinetic resolution of reversibly generated chiral cyanohydrins. A chiral bifunctional organocatalyst selectively recognizes a specific chair-like conformation of the intermediate, in which the small steric effect of the linear cyano group as well as its anomeric effect play important roles in controlling stereoselectivity. The products offer additional utility as synthetic intermediates because the cyano group can be further transformed into a variety of important functional groups. This strategy provides a platform to design efficient approaches to obtain a wide range of optically active tetrahydropyrans, which are otherwise synthetically challenging materials. Enantioselective synthesis of six-membered oxacycles with multiple stereogenic centres is essential for the discovery of new therapeutic agents. Here the authors show organocatalytic cycloetherification for the highly enantio- and diastereoselective synthesis of tetrahydropyrans.
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18
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Hasanzadeh N, Nori-Shargh D, Yahyaei H, Mousavi SN, Kamrava S. Exploring the Origin of the Generalized Anomeric Effects in the Acyclic Nonplanar Systems. J Phys Chem A 2017; 121:5548-5560. [PMID: 28661674 DOI: 10.1021/acs.jpca.7b04447] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Contrary to the published conclusions in the literature concerning the origin of the generalized anomeric relationships in open-chain nonplanar systems, its origin has remained an open question. In order to explore the origin of the generalized anomeric relationships in open-chain nonplanar systems, we assessed the roles and contributions of the effective factors on the conformational properties of methyl propargyl ether (1), methyl propargyl sulfide (2), and methyl propargyl selenide (3) by means of the G3MP2, CCSD(T), MP2, LC-ωPBE, and B3LYP methods and natural bond orbital (NBO) interpretations. We examined the contributions of the hyperconjugative interactions on the conformational preferences of compounds 1-3 by the deletions of the orbitals overlapping from the Fock matrices of the gauche- and anti-conformations. The trend observed for energy changes in the Fock matrices justify the variations of the gauche-conformations preferences going from compound 1 to compound 3, revealing that the hyperconjugative interactions are solely responsible for the generalized anomeric relationships in compounds 1-3. Accordingly, the conclusions published in the literature concerning the origin of the generalized anomeric effect in the acyclic nonplanar compounds should be revised by these findings. The Pauli exchange type repulsions (PETR) are in favors of the gauche-conformations and the variations of the PETR differences between the gauche- and anti-conformations of compounds 1-3 correlate well with their gauche-conformations preferences, revealing that the generalized anomeric relationships in compounds 1-3 have also the Pauli exchange-type repulsions origin. The resemblance between the preorthogonal natural bond orbitals (that are involved in the hyperconjugative interactions) and their corresponding molecular orbitals have been investigated.
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Affiliation(s)
- Neda Hasanzadeh
- Department of Chemistry, Ahvaz Branch, Islamic Azad University , Ahvaz, Iran
| | - Davood Nori-Shargh
- Department of Chemistry, Arak Branch, Islamic Azad University , Arak, Iran
| | - Hooriye Yahyaei
- Department of Chemistry, Zanjan Branch, Islamic Azad University , Zanjan, Iran
| | - Seiedeh Negar Mousavi
- Department of Nanochemistry, Faculty of Pharmaceutical Chemistry, Pharmaceutical Science Branch, Islamic Azad University (IAUPS) , Tehran, Iran
| | - Sahar Kamrava
- Department of Chemistry, Arak Branch, Islamic Azad University , Arak, Iran
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19
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Atabaki H, Nori-Shargh D, Momen-Heravi M. Assessing the effective factors affecting the conformational preferences and the early and late transition states of the unimolecular retro-ene decomposition reactions of ethyl cyanate, ethyl thiocyanate and ethyl selenocyanate. RSC Adv 2017. [DOI: 10.1039/c7ra00520b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The variations of Δ[(HCGAE(X3–C4weakening) – HCGAE(X3–C4strengthening)] parameters correlate well with the variations of the retro-ene decomposition reactions barrier heights going from compound1to compound3.
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Affiliation(s)
- Hooshang Atabaki
- Department of Chemistry
- College of Science
- Islamic Azad University
- Mashhad
- Iran
| | - Davood Nori-Shargh
- Department of Chemistry
- College of Science
- Islamic Azad University
- Arak
- Iran
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20
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Behrouz A, Nori-Shargh D. The Importance of the Pauli Exchange-Type Repulsions and Hyperconjugative Interactions on the Conformational Properties of Halocarbonyl Isocyanates and Halocarbonyl Azides. Aust J Chem 2017. [DOI: 10.1071/ch16227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To gain further insight into the origin of the anomeric relationships in planar open-chain (acyclic) compounds, we examined the effects of the hyperconjugative generalized anomeric effect (HC-GAE), Pauli exchange-type repulsion (PETR), the electrostatic model associated with the dipole–dipole interactions (EM-DDI), and the attractive electrostatic interactions (AEI) between the natural atomic charges (NACs) on the conformational properties of halocarbonyl isocyanates [halogen = F (1), Cl (2), Br (3)] and halocarbonyl azides [halogen = F (4), Cl (5), Br (6)] by means of G3MP2, CCSD, MP2, and B3LYP methods with the 6–311+G** basis set on all atoms and natural bond orbital interpretation. Importantly, the deletions of the through bond LPN3→σ*C2–X6 hyperconjugative interactions from the Fock matrices of the cis- and trans-conformations lead to the increase of the cis-conformations’ stability compared with their corresponding trans-conformations going from compound 1 to 3 and from compound 4 to 6, revealing the determining effects on the conformational preferences in compounds 1–3 and 4–6. Essentially, the effects of the through space (LPN3→σ*C4–O5 and LPNα→π*Nβ=Nω, respectively) hyperconjugative interactions on the conformational preferences in the isocyanate (1–3) and azide compounds (4–6) are negligible. The EM-DDI fails to account for the conformational preferences in compounds 2, 3, 5, and 6. Therefore, the generalized anomeric relationships in compounds 1–3 and 4–6 result from the cooperative effects of the HC-GAE and PETR. The variations of the AEIs revealed their opposite effects on the trend observed for the conformational preferences in compounds 1–3 and 4–6. Contrary to the usual assumption, the much larger barrier heights of the rotation around the C2–N3 bonds in the azide compounds (4–6) compared with those in the isocyanate compounds (1–3) result from the exchange components and have no hyperconjugative origin.
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21
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Nori-Shargh D, Mousavi SN, Tale R, Yahyaei H. Hyperconjugative interactions are the main responsible for the anomeric effect: a direct relationship between the hyperconjugative anomeric effect, global hardness and zero-point energy. Struct Chem 2016. [DOI: 10.1007/s11224-016-0791-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Ghanbarpour P, Nori-Shargh D. Exploring the origin of the anomeric relationships in 2-cyanooxane, 2-cyanothiane, 2-cyanoselenane and their corresponding isocyano isomers. Correlations between hyper-conjugative anomeric effect, hardness and electrostatic interactions. RSC Adv 2016. [DOI: 10.1039/c6ra06080c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The impacts of the HCAE, hardness, PETR and electrostatic interactions on the anomeric relationships in 2-cyanooxane, -thiane, -selenane and their iso-cyano isomers have been explored.
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Affiliation(s)
- Peyvand Ghanbarpour
- Department of Chemistry
- College of Science
- Arak Branch
- Islamic Azad University
- Arak
| | - Davood Nori-Shargh
- Department of Chemistry
- College of Science
- Arak Branch
- Islamic Azad University
- Arak
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Usabiaga I, González J, Arnáiz PF, León I, Cocinero EJ, Fernández JA. Modeling the tyrosine–sugar interactions in supersonic expansions: glucopyranose–phenol clusters. Phys Chem Chem Phys 2016; 18:12457-65. [DOI: 10.1039/c6cp00560h] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present here the structure of glucopyranoe–phenol complexes, as revealed by mass-resolved laser spectroscopy and DFT calculations.
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Affiliation(s)
- Imanol Usabiaga
- Dep. of Physical Chemistry
- Fac. of Science and Technology
- University of the Basque Country (UPV/EHU)
- 48940 Leioa
- Spain
| | - Jorge González
- Dep. of Physical Chemistry
- Fac. of Science and Technology
- University of the Basque Country (UPV/EHU)
- 48940 Leioa
- Spain
| | - Pedro F. Arnáiz
- Dep. of Physical Chemistry
- Fac. of Science and Technology
- University of the Basque Country (UPV/EHU)
- 48940 Leioa
- Spain
| | - Iker León
- Dep. of Physical Chemistry
- Fac. of Science and Technology
- University of the Basque Country (UPV/EHU)
- 48940 Leioa
- Spain
| | - Emilio J. Cocinero
- Dep. of Physical Chemistry
- Fac. of Science and Technology
- University of the Basque Country (UPV/EHU)
- 48940 Leioa
- Spain
| | - José A. Fernández
- Dep. of Physical Chemistry
- Fac. of Science and Technology
- University of the Basque Country (UPV/EHU)
- 48940 Leioa
- Spain
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24
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Ortega PGR, Montejo M, López González JJ. Hyperconjugative and Electrostatic Interactions as Anomeric Triggers in Archetypical 1,4-Dioxane Derivatives. Chemphyschem 2015; 17:530-40. [DOI: 10.1002/cphc.201500989] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Indexed: 11/10/2022]
Affiliation(s)
| | - Manuel Montejo
- Department of Physical and Analytical Chemistry; University of Jaén; 23071 Jaén Spain
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25
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Rodrigues-Santos CE, Echevarria A, Sant’Anna CMR, Bitencourt TB, Nascimento MG, Bauerfeldt GF. Quantitative Structure-Property Relationship (QSPR) Models for a Local Quantum Descriptor: Investigation of the 4- and 3-Substituted-Cinnamic Acid Esterification. Molecules 2015; 20:17493-510. [PMID: 26402661 PMCID: PMC6331874 DOI: 10.3390/molecules200917493] [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: 06/27/2015] [Revised: 09/12/2015] [Accepted: 09/15/2015] [Indexed: 11/16/2022] Open
Abstract
In this work, the theoretical description of the 4- and 3-substituted-cinnamic acid esterification with different electron donating and electron withdrawing groups was performed at the B3LYP and M06-2X levels, as a two-step process: the O-protonation and the nucleophile attack by ethanol. In parallel, an experimental work devoted to the synthesis and characterization of the substituted-cinnamate esters has also been performed. In order to quantify the substituents effects, quantitative structure–property relationship (QSPR) models based on the atomic charges, Fukui functions and the Frontier Effective-for-Reaction Molecular Orbitals (FERMO) energies were investigated. In fact, the Fukui functions, ƒ+C and ƒ−O, indicated poor correlations for each individual step, and in contrast with the general literature, the O-protonation step is affected both by the FERMO energies and the O-charges of the carbonyl group. Since the process was shown to not be totally described by either charge- or frontier-orbitals, it is proposed to be frontier-charge-miscere controlled. Moreover, the observed trend for the experimental reaction yields suggests that the electron withdrawing groups favor the reaction and the same was observed for Step 2, which can thus be pointed out as the determining step.
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Affiliation(s)
- Cláudio E. Rodrigues-Santos
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro-RJ, Seropédica 23890-900, Brazil; E-Mails: (C.E.R.-S.); (A.E.); (C.M.R.S.)
| | - Aurea Echevarria
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro-RJ, Seropédica 23890-900, Brazil; E-Mails: (C.E.R.-S.); (A.E.); (C.M.R.S.)
| | - Carlos M. R. Sant’Anna
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro-RJ, Seropédica 23890-900, Brazil; E-Mails: (C.E.R.-S.); (A.E.); (C.M.R.S.)
| | - Thiago B. Bitencourt
- Departamento de Engenharia de Alimentos, Universidade Federal da Fronteira Sul, Laranjeiras do Sul-PR 85303-775, Brazil; E-Mail:
| | - Maria G. Nascimento
- Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis-SC 88040-900, Brazil; E-Mail:
| | - Glauco F. Bauerfeldt
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro-RJ, Seropédica 23890-900, Brazil; E-Mails: (C.E.R.-S.); (A.E.); (C.M.R.S.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel./Fax: +55-21-2682-2807
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26
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Abstract
The article reviews the significant contributions to, and the present status of, applications of computational methods for the characterization and prediction of protein-carbohydrate interactions. After a presentation of the specific features of carbohydrate modeling, along with a brief description of the experimental data and general features of carbohydrate-protein interactions, the survey provides a thorough coverage of the available computational methods and tools. At the quantum-mechanical level, the use of both molecular orbitals and density-functional theory is critically assessed. These are followed by a presentation and critical evaluation of the applications of semiempirical and empirical methods: QM/MM, molecular dynamics, free-energy calculations, metadynamics, molecular robotics, and others. The usefulness of molecular docking in structural glycobiology is evaluated by considering recent docking- validation studies on a range of protein targets. The range of applications of these theoretical methods provides insights into the structural, energetic, and mechanistic facets that occur in the course of the recognition processes. Selected examples are provided to exemplify the usefulness and the present limitations of these computational methods in their ability to assist in elucidation of the structural basis underlying the diverse function and biological roles of carbohydrates in their dialogue with proteins. These test cases cover the field of both carbohydrate biosynthesis and glycosyltransferases, as well as glycoside hydrolases. The phenomenon of (macro)molecular recognition is illustrated for the interactions of carbohydrates with such proteins as lectins, monoclonal antibodies, GAG-binding proteins, porins, and viruses.
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Affiliation(s)
- Serge Pérez
- Department of Molecular Pharmacochemistry, CNRS, University Grenoble-Alpes, Grenoble, France.
| | - Igor Tvaroška
- Department of Chemistry, Slovak Academy of Sciences, Bratislava, Slovak Republic; Department of Chemistry, Faculty of Natural Sciences, Constantine The Philosopher University, Nitra, Slovak Republic.
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27
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Ruzziconi R, Lepri S, Buonerba F, Schlosser M, Mancinelli M, Ranieri S, Prati L, Mazzanti A. Long-Range Bonding/Nonbonding Interactions: A Donor–Acceptor Resonance Studied by Dynamic NMR. Org Lett 2015; 17:2740-3. [DOI: 10.1021/acs.orglett.5b01152] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Renzo Ruzziconi
- Department
of Chemistry, Biology and Biotechnology, University of Perugia, via Elce di Sotto 10, I-06100 Perugia, Italy
| | - Susan Lepri
- Department
of Chemistry, Biology and Biotechnology, University of Perugia, via Elce di Sotto 10, I-06100 Perugia, Italy
| | - Federica Buonerba
- Department
of Chemistry, Biology and Biotechnology, University of Perugia, via Elce di Sotto 10, I-06100 Perugia, Italy
| | - Manfred Schlosser
- Institute
of Chemical Sciences, Ecole Polytechnique Fédérale, CH-1015 Lausanne, Switzerland
| | - Michele Mancinelli
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Silvia Ranieri
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Luca Prati
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Andrea Mazzanti
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
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28
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Totani K, Shinoda Y, Shiba M, Iwamoto S, Koizumi A, Matsuzaki Y, Hirano M. Silyl-assisted 1,2-cis-α-glucosylation for the synthesis of a triglucoside moiety in high-mannose-type oligosaccharides. RSC Adv 2015. [DOI: 10.1039/c5ra16659d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We developed a new 1,2-cis-α-glucosylation reaction, mediated by enhancing the α-favoured transition state via an electron-donating form the TBS group.
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Affiliation(s)
- Kiichiro Totani
- Department of Materials and Life Science
- Seikei University
- Tokyo 180-8633
- Japan
| | - Yuki Shinoda
- Department of Materials and Life Science
- Seikei University
- Tokyo 180-8633
- Japan
| | - Masaaki Shiba
- Department of Materials and Life Science
- Seikei University
- Tokyo 180-8633
- Japan
| | - Shogo Iwamoto
- Department of Materials and Life Science
- Seikei University
- Tokyo 180-8633
- Japan
| | - Akira Koizumi
- Department of Materials and Life Science
- Seikei University
- Tokyo 180-8633
- Japan
| | - Yuji Matsuzaki
- Glyco Synthetic Lab
- Tokyo Chemical Industry Co., Ltd
- Tokyo 114-0003
- Japan
| | - Makoto Hirano
- Department of Materials and Life Science
- Seikei University
- Tokyo 180-8633
- Japan
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29
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Deshmukh MM, Gadre SR, Cocinero EJ. Stability of conformationally locked free fructose: theoretical and computational insights. NEW J CHEM 2015. [DOI: 10.1039/c5nj02106e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Total stabilization is governed by three predominant factors viz. the sum of energy of all H-bonds, ring strain and anomeric stabilization.
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Affiliation(s)
- Milind M. Deshmukh
- Department of Chemistry
- Dr. Harisingh Gour Central University
- Sagar, 470003
- India
| | - Shridhar R. Gadre
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur 208 016
- India
| | - Emilio J. Cocinero
- Departamento de Química Física
- Facultad de Ciencia y Tecnología
- Universidad del País Vasco (UPV-EHU)
- 48080 Bilbao
- Spain
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30
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Hasanzadeh N, Nori-Shargh D, Farzipour M, Ahmadi B. The origin of the anomeric effect: probing the impacts of stereoelectronic interactions. Org Biomol Chem 2015; 13:6965-76. [DOI: 10.1039/c5ob00585j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To gain further insight on the origin of the anomeric effect, the correlations between SE, EM, PETR, bond-orders, donor and acceptor orbital energies and occupancies, structural parameters and configurational behavior of dihalo-1,4-oxathianes were investigated.
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Affiliation(s)
- Neda Hasanzadeh
- Department of Chemistry
- Ahvaz Branch
- Islamic Azad University
- Ahvaz
- Iran
| | | | | | - Bahareh Ahmadi
- Department of Chemistry
- Arak Branch
- Islamic Azad University
- Arak
- Iran
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31
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Sladek V, Holka F, Tvaroška I. Ab initio modelling of the anomeric and exo anomeric effects in 2-methoxytetrahydropyran and 2-methoxythiane corrected for intramolecular BSSE. Phys Chem Chem Phys 2015; 17:18501-13. [DOI: 10.1039/c5cp02191j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oxygen substitution in 2-methoxytetrahydropyran by sulphur in 2-methoxythiane approximately doubles the anomeric effect, which slows down enzymatic processing of 2-methoxythiane.
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Affiliation(s)
- Vladimir Sladek
- Institute of Chemistry
- Slovak Academy of Sciences
- SK-845 38 Bratislava
- Slovakia
| | - Filip Holka
- Faculty of Materials Science and Technology in Trnava
- Slovak University of Technology in Bratislava
- SK-917 24 Trnava
- Slovakia
| | - Igor Tvaroška
- Institute of Chemistry
- Slovak Academy of Sciences
- SK-845 38 Bratislava
- Slovakia
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32
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Xu B, Unione L, Sardinha J, Wu S, Ethève-Quelquejeu M, Pilar Rauter A, Blériot Y, Zhang Y, Martín-Santamaría S, Díaz D, Jiménez-Barbero J, Sollogoub M. gem-Difluorocarbadisaccharides: Restoring theexo-Anomeric Effect. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201405008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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33
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Xu B, Unione L, Sardinha J, Wu S, Ethève-Quelquejeu M, Pilar Rauter A, Blériot Y, Zhang Y, Martín-Santamaría S, Díaz D, Jiménez-Barbero J, Sollogoub M. gem-Difluorocarbadisaccharides: Restoring theexo-Anomeric Effect. Angew Chem Int Ed Engl 2014; 53:9597-602. [DOI: 10.1002/anie.201405008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/06/2014] [Indexed: 11/06/2022]
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34
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Silla JM, Freitas MP. Polar and stereoelectronic effects on the structural and spectroscopic properties of halomethanols. COMPUT THEOR CHEM 2014. [DOI: 10.1016/j.comptc.2014.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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35
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Anomeric effects in fluoro and trifluoromethyl piperidines: a computational study of conformational preferences and hydration. Theor Chem Acc 2014. [DOI: 10.1007/s00214-014-1491-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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36
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Solha DC, Barbosa TM, Viesser RV, Rittner R, Tormena CF. Experimental and Theoretical Studies of Intramolecular Hydrogen Bonding in 3-Hydroxytetrahydropyran: Beyond AIM Analysis. J Phys Chem A 2014; 118:2794-800. [DOI: 10.1021/jp500211y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Daniela C. Solha
- Chemistry Institute, University of Campinas - UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
| | - Thaís M. Barbosa
- Chemistry Institute, University of Campinas - UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
| | - Renan V. Viesser
- Chemistry Institute, University of Campinas - UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
| | - Roberto Rittner
- Chemistry Institute, University of Campinas - UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
| | - Cláudio F. Tormena
- Chemistry Institute, University of Campinas - UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
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37
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Conformational studies of gas-phase ribose and 2-deoxyribose by density functional, second order PT and multi-level method calculations: the pyranoses, furanoses, and open-chain structures. Carbohydr Res 2014; 384:20-36. [DOI: 10.1016/j.carres.2013.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 09/09/2013] [Accepted: 10/18/2013] [Indexed: 11/21/2022]
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38
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Peña I, Cocinero EJ, Cabezas C, Lesarri A, Mata S, Écija P, Daly AM, Cimas Á, Bermúdez C, Basterretxea FJ, Blanco S, Fernández JA, López JC, Castaño F, Alonso JL. Six Pyranoside Forms of Free 2-Deoxy-D-ribose. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201305589] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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39
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Peña I, Cocinero EJ, Cabezas C, Lesarri A, Mata S, Écija P, Daly AM, Cimas Á, Bermúdez C, Basterretxea FJ, Blanco S, Fernández JA, López JC, Castaño F, Alonso JL. Six Pyranoside Forms of Free 2-Deoxy-D-ribose. Angew Chem Int Ed Engl 2013; 52:11840-5. [DOI: 10.1002/anie.201305589] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Indexed: 11/09/2022]
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40
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Bent bonds and the antiperiplanar hypothesis as a simple model to predict Diels–Alder reactivity: retrospective or perspective? Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.05.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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41
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Freitas MP. The anomeric effect on the basis of natural bond orbital analysis. Org Biomol Chem 2013; 11:2885-90. [DOI: 10.1039/c3ob40187a] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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