1
|
Anderson TE, Thamattoor DM, Phillips DL. Formation of 3-Oxa- and 3-Thiacyclohexyne from Ring Expansion of Heterocyclic Alkylidene Carbenes: A Mechanistic Study. Org Lett 2023; 25:1364-1369. [PMID: 36856659 PMCID: PMC10012261 DOI: 10.1021/acs.orglett.3c00042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
The rearrangement pathways of two alkylidene carbenes appended to an oxa or thiacyclopentane into the corresponding heterocyclohexynes were elucidated using 13C-labeling experiments. Both carbenes exhibited a preference for migration of the allylic carbon bound to the heteroatom. Anomeric interactions involving a heteroatom lone pair and antibonding orbital of the migrating bond and inductive destabilization of the minor migratory pathway are discussed as plausible reasons for the observed trends.
Collapse
Affiliation(s)
- T E Anderson
- Department of Chemistry, Colby College, 5765 Mayflower Hill, Waterville, Maine 04901, USA
| | - Dasan M Thamattoor
- Department of Chemistry, Colby College, 5765 Mayflower Hill, Waterville, Maine 04901, USA
| | - David Lee Phillips
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Pok Fu Lam 999077, Hong Kong S.A.R
| |
Collapse
|
2
|
Masnabadi N, Thalji MR, Alhasan HS, Mahmoodi Z, Soldatov AV, Ali GAM. Structural, Electronic, Reactivity, and Conformational Features of 2,5,5-Trimethyl-1,3,2-diheterophosphinane-2-sulfide, and Its Derivatives: DFT, MEP, and NBO Calculations. Molecules 2022; 27:molecules27134011. [PMID: 35807257 PMCID: PMC9268642 DOI: 10.3390/molecules27134011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/11/2022] [Accepted: 06/17/2022] [Indexed: 01/18/2023] Open
Abstract
In this study, we used density functional theory (DFT) and natural bond orbital (NBO) analysis to determine the structural, electronic, reactivity, and conformational features of 2,5,5-trimethyl-1,3,2-di-heteroatom (X) phosphinane-2-sulfide derivatives (X = O (compound 1), S (compound 2), and Se (compound 3)). We discovered that the features improve dramatically at 6-31G** and B3LYP/6-311+G** levels. The level of theory for the molecular structure was optimized first, followed by the frontier molecular orbital theory development to assess molecular stability and reactivity. Molecular orbital calculations, such as the HOMO–LUMO energy gap and the mapping of molecular electrostatic potential surfaces (MEP), were performed similarly to DFT calculations. In addition, the electrostatic potential of the molecule was used to map the electron density on a surface. In addition to revealing molecules’ size and shape distribution, this study also shows the sites on the surface where molecules are most chemically reactive.
Collapse
Affiliation(s)
- Nasrin Masnabadi
- Department of Chemistry, Roudehen Branch, Islamic Azad University, Roudehen P.O. Box 189, Iran
- Correspondence: or (N.M.); or (G.A.M.A.)
| | - Mohammad R. Thalji
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Korea;
| | - Huda S. Alhasan
- Environmental Research and Studies Center, University of Babylon, Babil 51002, Iraq;
| | - Zahra Mahmoodi
- Department of Chemistry, University of Applied Science and Technology, Center of Arya Gach Poldokhtar, Tehran P.O. Box 68, Iran;
| | - Alexander V. Soldatov
- The Smart Materials Research Institute, Southern Federal University, Sladkova Str. 178/24, Rostov-on-Don 344006, Russia;
| | - Gomaa A. M. Ali
- Chemistry Department, Faculty of Science, Al-Azhar University, Assiut 71524, Egypt
- Correspondence: or (N.M.); or (G.A.M.A.)
| |
Collapse
|
3
|
Khazhiev S, Khusainov M, Khalikov R, Kataev V, Tyumkina T, Mescheryakova E, Khalilov L, Kuznetsov V. Structure and conformational analysis of 5,5-bis(bromomethyl)-2-trichloromethyl-1,3-dioxane by XRD, NMR and computer simulation. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.132326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
4
|
Vallejos González V, Podlech J. Oxidation of Dithia Compounds: Comparative Experimental and Theoretical Studies on 1,3‐Bis(methylthio)propane, Bis(methylthio)methane, and
meso
‐4,6‐Dimethyl‐1,3‐dithiane. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Victorino Vallejos González
- Institut für Organische Chemie Karlsruher Institut für Technologie (KIT) 76131 Karlsruhe Fritz-Haber-Weg 6 Germany
| | - Joachim Podlech
- Institut für Organische Chemie Karlsruher Institut für Technologie (KIT) 76131 Karlsruhe Fritz-Haber-Weg 6 Germany
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Alabugin IV, Kuhn L, Medvedev MG, Krivoshchapov NV, Vil' VA, Yaremenko IA, Mehaffy P, Yarie M, Terent'ev AO, Zolfigol MA. Stereoelectronic power of oxygen in control of chemical reactivity: the anomeric effect is not alone. Chem Soc Rev 2021; 50:10253-10345. [PMID: 34263287 DOI: 10.1039/d1cs00386k] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Although carbon is the central element of organic chemistry, oxygen is the central element of stereoelectronic control in organic chemistry. Generally, a molecule with a C-O bond has both a strong donor (a lone pair) and a strong acceptor (e.g., a σ*C-O orbital), a combination that provides opportunities to influence chemical transformations at both ends of the electron demand spectrum. Oxygen is a stereoelectronic chameleon that adapts to the varying situations in radical, cationic, anionic, and metal-mediated transformations. Arguably, the most historically important stereoelectronic effect is the anomeric effect (AE), i.e., the axial preference of acceptor groups at the anomeric position of sugars. Although AE is generally attributed to hyperconjugative interactions of σ-acceptors with a lone pair at oxygen (negative hyperconjugation), recent literature reports suggested alternative explanations. In this context, it is timely to evaluate the fundamental connections between the AE and a broad variety of O-functional groups. Such connections illustrate the general role of hyperconjugation with oxygen lone pairs in reactivity. Lessons from the AE can be used as the conceptual framework for organizing disjointed observations into a logical body of knowledge. In contrast, neglect of hyperconjugation can be deeply misleading as it removes the stereoelectronic cornerstone on which, as we show in this review, the chemistry of organic oxygen functionalities is largely based. As negative hyperconjugation releases the "underutilized" stereoelectronic power of unshared electrons (the lone pairs) for the stabilization of a developing positive charge, the role of orbital interactions increases when the electronic demand is high and molecules distort from their equilibrium geometries. From this perspective, hyperconjugative anomeric interactions play a unique role in guiding reaction design. In this manuscript, we discuss the reactivity of organic O-functionalities, outline variations in the possible hyperconjugative patterns, and showcase the vast implications of AE for the structure and reactivity. On our journey through a variety of O-containing organic functional groups, from textbook to exotic, we will illustrate how this knowledge can predict chemical reactivity and unlock new useful synthetic transformations.
Collapse
Affiliation(s)
- Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Leah Kuhn
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, 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
| | - 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
| | - Vera A Vil'
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Ivan A Yaremenko
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Patricia Mehaffy
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Meysam Yarie
- Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65167, Iran
| | - Alexander O Terent'ev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Mohammad Ali Zolfigol
- Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65167, Iran
| |
Collapse
|
7
|
Jindani S, Ganguly B. Exploiting the role of stereoelectronic effects to design the antagonists of the human complement C3a receptor. NEW J CHEM 2021. [DOI: 10.1039/d1nj00730k] [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
Stereoelectronic effects are crucial in governing the conformational behaviour of small molecules bearing heterocyclic rings adjacent to amides.
Collapse
Affiliation(s)
- Sana Jindani
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility)
- CSIR-Central Salt and Marine Chemicals Research Institute
- Bhavnagar 364002
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Bishwajit Ganguly
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility)
- CSIR-Central Salt and Marine Chemicals Research Institute
- Bhavnagar 364002
- India
- Academy of Scientific and Innovative Research (AcSIR)
| |
Collapse
|
8
|
Chang CW, Lin MH, Wang CC. Statistical Analysis of Glycosylation Reactions. Chemistry 2020; 27:2556-2568. [PMID: 32939892 DOI: 10.1002/chem.202003105] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/15/2020] [Indexed: 12/27/2022]
Abstract
Chemical synthesis is one of the practical approaches to access carbohydrate-based natural products and their derivatives with high quality and in a large quantity. However, stereoselectivity during the glycosylation reaction is the main challenge because the reaction can generate both α- and β-glycosides. The main focus of the present article is the concept of recent mechanistic studies that have applied statistical analysis and quantitation for defining stereoselective changes during the reaction process. Based on experimental evidence, a detailed discussion associated with the mechanism and degree of influence affecting the stereoselective outcome of glycosylation is included.
Collapse
Affiliation(s)
- Chun-Wei Chang
- Institute of Chemistry, Academia Sinica, Taipei, 115, Taiwan
| | - Mei-Huei Lin
- Institute of Chemistry, Academia Sinica, Taipei, 115, Taiwan
| | - Cheng-Chung Wang
- Institute of Chemistry, Academia Sinica, Taipei, 115, Taiwan.,Chemical Biology and Molecular Biophysics Program (Taiwan), International Graduate Program (TIGP), Academia Sinica, Taipei, 115, Taiwan
| |
Collapse
|
9
|
Jung ST, Nickisch R, Reinsperger T, Luy B, Podlech J. Stereoelectronic effects: Perlin effects in cyclohexane‐derived compounds. J PHYS ORG CHEM 2020. [DOI: 10.1002/poc.4165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Sebastian T. Jung
- Institute for Organic Chemistry Karlsruher Institute of Technology (KIT) Karlsruhe Germany
| | - Roman Nickisch
- Institute for Organic Chemistry Karlsruher Institute of Technology (KIT) Karlsruhe Germany
| | - Tony Reinsperger
- Institute for Organic Chemistry Karlsruher Institute of Technology (KIT) Karlsruhe Germany
- Institute for Biological Interfaces 4—Magnetic Resonance Karlsruher Institute of Technology (KIT) Eggenstein‐Leopoldshafen Germany
| | - Burkhard Luy
- Institute for Organic Chemistry Karlsruher Institute of Technology (KIT) Karlsruhe Germany
- Institute for Biological Interfaces 4—Magnetic Resonance Karlsruher Institute of Technology (KIT) Eggenstein‐Leopoldshafen Germany
| | - Joachim Podlech
- Institute for Organic Chemistry Karlsruher Institute of Technology (KIT) Karlsruhe Germany
| |
Collapse
|
10
|
Bochet CG, Harvey FM. Is there a photochemical Hammond postulate? Chem Sci 2020; 12:599-605. [PMID: 34163790 PMCID: PMC8178980 DOI: 10.1039/d0sc04370b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/03/2020] [Indexed: 12/11/2022] Open
Abstract
The Hammond postulate is a useful tool for approximating the energy and the structure of transition states. It was designed for use in ground state reactions, and has been applied successfully on many occasions. On the other hand, its usefulness for photochemical reactions is more questionable, as different energy surfaces are involved. So far, no systematic studies on the validity of the Hammond postulate for photochemical reactions are available. The present work aims at filling this gap by providing a simple, unbiased series of test reactions based on the stereospecificity of isotopically labelled substrates.
Collapse
Affiliation(s)
- Christian G Bochet
- Department of Chemistry, University of Fribourg Chemin du Musée 9 CH-1700 Fribourg Switzerland
| | - Freya M Harvey
- Department of Chemistry, University of Fribourg Chemin du Musée 9 CH-1700 Fribourg Switzerland
| |
Collapse
|
11
|
|
12
|
Morteza Nasrolahi, Ghiasi R, Shafiei F. Theoretical Approaches to the Conformational Preference of 2,2-Di-tert-Butyl-1,3-Dioxane, 2,2-Di-tert-Butyl-1,3-Dithian, and 2,2-Di-tert-Butyl-1,3-Diselenan. RUSS J INORG CHEM+ 2020. [DOI: 10.1134/s0036023619120118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
13
|
Pecio Ł, Alilou M, Kozachok S, Erdogan Orhan I, Eren G, Senol Deniz FS, Stuppner H, Oleszek W. Yuccalechins A-C from the Yucca schidigera Roezl ex Ortgies Bark: Elucidation of the Relative and Absolute Configurations of Three New Spirobiflavonoids and Their Cholinesterase Inhibitory Activities. Molecules 2019; 24:molecules24224162. [PMID: 31744162 PMCID: PMC6891570 DOI: 10.3390/molecules24224162] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 12/16/2022] Open
Abstract
The ethyl acetate fraction of the methanolic extract of Yucca schidigera Roezl ex Ortgies bark exhibited moderate acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity (IC50 47.44 and 47.40 µg mL−1, respectively). Gel filtration on Sephadex LH-20 and further RP-C18 preparative HPLC of EtOAc fraction afforded 15 known and 3 new compounds, stereoisomers of larixinol. The structures of the isolated spirobiflavonoids 15, 26, and 29 were elucidated using 1D and 2D NMR and MS spectroscopic techniques. The relative configuration of isolated compounds was assigned based on coupling constants and ROESY (rotating-frame Overhauser spectroscopy) correlations along with applying the DP4+ probability method in case of ambiguous chiral centers. Determination of absolute configuration was performed by comparing calculated electronic circular dichroism (ECD) spectra with experimental ones. Compounds 26 and 29, obtained in sufficient amounts, were evaluated for activities against AChE and BChE, and they showed a weak inhibition only towards AChE (IC50 294.18 µM for 26, and 655.18 µM for 29). Furthermore, molecular docking simulations were performed to investigate the possible binding modes of 26 and 29 with AChE.
Collapse
Affiliation(s)
- Łukasz Pecio
- Department of Biochemistry and Crop Quality, Institute of Soil Science and Plant Cultivation-State Research Institute, Czartoryskich 8, 24-100 Puławy, Poland; (S.K.); (W.O.)
- Correspondence: (Ł.P.); (M.A.); Tel.: +48-814-786-882 (Ł.P.); +43-512-507-58437 (M.A.)
| | - Mostafa Alilou
- Institute of Pharmacy/Pharmacognosy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80/82, Innsbruck 6020, Austria;
- Correspondence: (Ł.P.); (M.A.); Tel.: +48-814-786-882 (Ł.P.); +43-512-507-58437 (M.A.)
| | - Solomiia Kozachok
- Department of Biochemistry and Crop Quality, Institute of Soil Science and Plant Cultivation-State Research Institute, Czartoryskich 8, 24-100 Puławy, Poland; (S.K.); (W.O.)
| | - Ilkay Erdogan Orhan
- Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey; (I.E.O.); (F.S.S.D.)
| | - Gokcen Eren
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey;
| | - Fatma Sezer Senol Deniz
- Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey; (I.E.O.); (F.S.S.D.)
| | - Hermann Stuppner
- Institute of Pharmacy/Pharmacognosy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80/82, Innsbruck 6020, Austria;
| | - Wiesław Oleszek
- Department of Biochemistry and Crop Quality, Institute of Soil Science and Plant Cultivation-State Research Institute, Czartoryskich 8, 24-100 Puławy, Poland; (S.K.); (W.O.)
| |
Collapse
|
14
|
Donnelly DP, Agar J, Lopez SA. Nucleophilic substitution reactions of cyclic thiosulfinates are accelerated by hyperconjugative interactions. Chem Sci 2019. [DOI: 10.1039/c9sc01098j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Cyclic thiosulfinates are a class of biocompatible molecules, currently expanding our in vivo toolkit.
Collapse
Affiliation(s)
- Daniel P. Donnelly
- Department of Chemistry and Chemical Biology
- Northeastern University
- Boston
- USA
- Barnett Institute of Chemical and Biological Analysis
| | - Jeffrey N. Agar
- Department of Chemistry and Chemical Biology
- Northeastern University
- Boston
- USA
- Barnett Institute of Chemical and Biological Analysis
| | - Steven A. Lopez
- Department of Chemistry and Chemical Biology
- Northeastern University
- Boston
- USA
| |
Collapse
|
15
|
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]
|
16
|
Caserio MC, Kim JK. Studies in sulfur-nitrogen nucleophilicity. J PHYS ORG CHEM 2018. [DOI: 10.1002/poc.3841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - Jhong K. Kim
- Department of Chemistry; University of California Irvine; Irvine CA USA
| |
Collapse
|
17
|
Ma Y, Hu C, Guo H, Fan L, Yang S, Sun WH. Structure effect on transition mechanism of UV–visible absorption spectrum in polyimides: A density functional theory study. POLYMER 2018. [DOI: 10.1016/j.polymer.2018.06.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
18
|
Juaristi E, Notario R. Stereoelectronic Interactions Exhibited by 1 J C-H One-Bond Coupling Constants and Examination of the Possible Existence of the Intramolecular α-Effect in Six-Membered Oxygen-Containing Heterocycles. J Org Chem 2018; 83:3293-3298. [PMID: 29470070 DOI: 10.1021/acs.joc.8b00220] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
For more than five decades since its original conception, the α-effect has been advocated with arguments based on kinetic reactivity data. The present study was undertaken with the aim of gathering theoretical information on thermodynamic bond energy data in systems that could in principle give rise to intramolecular α-effects. In particular, oxygen-containing six-membered rings oxa-, 1,2-dioxa-, 1,3-dioxa-, 1,2,4-trioxa-, and 1,2,4,5-tetraoxacyclohexane were optimized at the B3LYP/aug-cc-pVTZ level of theory, and the magnitude of all C-H one-bond coupling constants was determined. Furthermore, hyperconjugative interactions were evaluated with Natural Bond Orbital analysis. Analysis of the collected information leads to the conclusion that ether oxygens are apparently better donors than peroxide oxygens; that is, the n(O) → σ*(C-Hax) two-orbital/two-electron interaction seems to be stronger than the n(O-O) → σ*(C-Hax) two-orbital/two-electron interaction, and this finding is contrary to expectations in terms of the α-effect.
Collapse
Affiliation(s)
- Eusebio Juaristi
- Departamento de Química , Centro de Investigación y de Estudios Avanzados , Av IPN No. 2508 , 07360 Ciudad de México , Mexico.,El Colegio Nacional , Luis González Obregón No. 23, Centro Histórico , 06020 Ciudad de México , Mexico
| | - Rafael Notario
- Instituto de Química Física "Rocasolano" , CSIC, c/Serrano 119 , 28006 Madrid , Spain
| |
Collapse
|
19
|
Valiakhmetova OY, Kuznetsov VV. Conformational analysis of 2-isopropyl-5-methyl-5-methoxymethyl-1,3,2-dioxaborinane. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2017. [DOI: 10.1134/s1070428017110112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
20
|
de la Fuente A, Verdaguer X, Riera A. Stereodivergent Syntheses of altro
and manno
Stereoisomers of 2-Acetamido-1,2-dideoxynojirimycin. European J Org Chem 2017. [DOI: 10.1002/ejoc.201701282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Alex de la Fuente
- Institute for Research in Biomedicine (IRB Barcelona); The Barcelona Institute of Science and Technology; Baldiri Reixac 10 08028 Barcelona Spain
| | - Xavier Verdaguer
- Institute for Research in Biomedicine (IRB Barcelona); The Barcelona Institute of Science and Technology; Baldiri Reixac 10 08028 Barcelona Spain
- Departament de Química Inorgànica i Orgànica; Secció Química Orgànica. Universitat de Barcelona; Martí i Franqués 1 08028 Barcelona Spain
| | - Antoni Riera
- Institute for Research in Biomedicine (IRB Barcelona); The Barcelona Institute of Science and Technology; Baldiri Reixac 10 08028 Barcelona Spain
- Departament de Química Inorgànica i Orgànica; Secció Química Orgànica. Universitat de Barcelona; Martí i Franqués 1 08028 Barcelona Spain
| |
Collapse
|
21
|
Juaristi E, dos Passos Gomes G, Terent’ev AO, Notario R, Alabugin IV. Stereoelectronic Interactions as a Probe for the Existence of the Intramolecular α-Effect. J Am Chem Soc 2017; 139:10799-10813. [DOI: 10.1021/jacs.7b05367] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Eusebio Juaristi
- Departamento
de Química, Centro de Investigación y de Estudios Avanzados, Av. Instituto Politécnico Nacional 2508, 07360 Ciudad de México, Mexico
- El Colegio Nacional, Luis González Obregón No. 23, Centro Histórico, 06020 Ciudad de México, Mexico
| | - Gabriel dos Passos Gomes
- Department
of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Alexander O. Terent’ev
- N.
D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prosp., 119991 Moscow, Russian Federation
| | - Rafael Notario
- Instituto
de Química Física “Rocasolano”, CSIC, c/Serrano 119, 28006 Madrid, Spain
| | - Igor V. Alabugin
- Department
of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| |
Collapse
|
22
|
Moon NG, Harned AM. Torsional steering as friend and foe: development of a synthetic route to the briarane diterpenoid stereotetrad. Org Biomol Chem 2017; 15:1876-1888. [PMID: 28169385 PMCID: PMC5330299 DOI: 10.1039/c7ob00124j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two synthetic routes to the briarane stereotetrad have been investigated. The first route employed a boron aldol reaction to establish the stereogenic all-carbon quaternary carbon (C1). In this case, it was found that torsional steering in the transition state led to the formation of the undesired configuration at this position. The second route makes use of a highly diastereoselective acetylide conjugate addition/β-ketoester alkylation sequence to construct the vicinal C1 and C10 stereocenters with the correct relative configuration. Originally, it was proposed that torsional steering in the transition state for the ketoester alkylation step was the primary factor responsible for generating the major product. DFT calculations reveal that while torsional steering does play a role, larger conformational factors must also be considered. These calculations also reveal that an unusual C-Hπ(alkyne) interaction may contribute to lowering the energy of one transition state that leads to the observed stereoisomer. Ultimately, this strategy leads to a concise synthesis (under 10 steps) of the stereotetrad core common to the briarane diterpenoids.
Collapse
Affiliation(s)
- Nicholas G Moon
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant St SE, Minneapolis, Minnesota 55455, USA
| | - Andrew M Harned
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant St SE, Minneapolis, Minnesota 55455, USA and Department of Chemistry & Biochemistry, Texas Tech University, MS 41061, Lubbock, Texas 79409-1061, USA.
| |
Collapse
|
23
|
Vasilevsky SF, Davydova MP, Mamatyuk VI, Tsvetkov N, Hughes A, Baranov DS, Alabugin IV. Full Cleavage of C≡C Bond in Electron-Deficient Alkynes via Reaction with Ethylenediamine. Aust J Chem 2017. [DOI: 10.1071/ch17026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Reaction of 1,2-diaminioethane (ethylenediamine) with electron-deficient alkynes leads to full scission of the C≡C bond even in the absence of a keto group directly attached to the alkyne. This process involves oxidation of one of the alkyne carbons into C2 of a 2-R-4,5-dihydroimidazole with the concomitant reduction of the other carbon to a methyl group. The sequence of Sonogashira coupling with the ethylenediamine-mediated fragmentation described in this work can be used for selective formal substitution of halogen in aryl halides by a methyl group or a 4,5-dihydroimidazol-2-yl moiety.
Collapse
|
24
|
Sabet-Sarvestani H, Eshghi H, Izadyar M. Understanding the mechanism, thermodynamic and kinetic features of the Kukhtin–Ramirez reaction in carbamate synthesis from carbon dioxide. RSC Adv 2017. [DOI: 10.1039/c6ra25769k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In this article, thermodynamic and kinetic aspects of the Kukhtin–Ramirez reaction of the carbamate formation from carbon dioxide have been investigated in the presence of various phosphorous reagents (PRs), theoretically.
Collapse
Affiliation(s)
| | - Hossein Eshghi
- Department of Chemistry
- Faculty of Sciences
- Ferdowsi University of Mashhad
- Mashhad
- Iran
| | - Mohammad Izadyar
- Department of Chemistry
- Faculty of Sciences
- Ferdowsi University of Mashhad
- Mashhad
- Iran
| |
Collapse
|
25
|
|
26
|
Vatsadze SZ, Loginova YD, dos Passos Gomes G, Alabugin IV. Stereoelectronic Chameleons: The Donor–Acceptor Dichotomy of Functional Groups. Chemistry 2016; 23:3225-3245. [DOI: 10.1002/chem.201603491] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Indexed: 01/28/2023]
Affiliation(s)
- Sergey Z. Vatsadze
- Department of Organic Chemistry, Faculty of Chemistry Lomonosov Moscow State University Leninsky gory, 1, 3 Moscow Russia
| | - Yulia D. Loginova
- Department of Organic Chemistry, Faculty of Chemistry Lomonosov Moscow State University Leninsky gory, 1, 3 Moscow Russia
| | - Gabriel dos Passos Gomes
- Department of Chemistry and Biochemistry Florida State University 95 Chieftan Way Tallahassee USA
| | - Igor V. Alabugin
- Department of Chemistry and Biochemistry Florida State University 95 Chieftan Way Tallahassee USA
| |
Collapse
|
27
|
|
28
|
Berry E, Gomes GDP, MacLean A, Martin JR, Wiget PA. Discovery of a Long-Range Perlin Effect in a Conformationally Constrained Oxocane. J Org Chem 2016; 81:5740-4. [DOI: 10.1021/acs.joc.6b00819] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Gabriel dos Passos Gomes
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | | | - Justin R. Martin
- Department
of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | | |
Collapse
|
29
|
Khaibullina GS, Kuznetsov VV, Meshcheriakova ES, Tyumkina TV, Khalilov LM. Molecular structure and conformational preference of 2-methyl-5-nitro-5-bromo-1,3,2-dioxaborinane and its complex with pyridine. J STRUCT CHEM+ 2016. [DOI: 10.1134/s0022476615070173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
30
|
Juaristi E, Notario R. Theoretical Evidence for the Relevance of n(F) → σ*(C–X) (X = H, C, O, S) Stereoelectronic Interactions. J Org Chem 2016; 81:1192-7. [DOI: 10.1021/acs.joc.5b02718] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eusebio Juaristi
- Departamento
de Química, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, Apartado Postal 14-740, 07000 México, D. F. Mexico
| | - Rafael Notario
- Instituto
de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain
| |
Collapse
|
31
|
Measurement, Interpretation and Use of Free Ligand Solution Conformations in Drug Discovery. PROGRESS IN MEDICINAL CHEMISTRY 2016; 55:45-147. [DOI: 10.1016/bs.pmch.2015.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
32
|
Shainyan BA, Kirpichenko SV, Chipanina NN, Oznobikhina LP, Kleinpeter E, Shlykov SA, Osadchiy DY. Synthesis and Conformational Analysis of 3-Methyl-3-silatetrahydropyran by GED, FTIR, NMR, and Theoretical Calculations: Comparative Analysis of 1-Hetero-3-methyl-3-silacyclohexanes. J Org Chem 2015; 80:12492-500. [PMID: 26587759 DOI: 10.1021/acs.joc.5b02355] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
3-Methyl-3-silatetrahydropyran 1 was synthesized and its molecular structure and conformational behavior was studied by gas-phase electron diffraction (GED), FTIR, low temperature (1)H and (13)C NMR spectroscopy, and by theoretical calculations (DFT, MP2). Two conformers, 1-ax and 1-eq, were located on the potential energy surface. In the gas phase, a slight predominance of the axial conformer was determined, with the ratio 1-ax:1-eq = 54(9):46(9) (from GED) or 53:47 or 61:39 (from IR). In solution, LT NMR spectroscopy at 103 K gives the ratio 1-ax:1-eq = 35:65 (-ΔG°103 = 0.13 kcal/mol). Simulation of solvent effects using the PCM continuum model or by calculation of the corresponding solvent-solute complexes allowed us to rationalize the experimentally observed opposite conformational predominance of the conformers of 3-methyl-3-silatetrahydropyran in the gas phase and in solution. Comparative analysis of the effect of heteroatom in 1-hetero-3-methyl-3-silacyclohexanes on the structure, stereoelectronic interactions, and relative energies of the conformers is done.
Collapse
Affiliation(s)
- Bagrat A Shainyan
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Division of the Russian Academy of Sciences , 1 Favorsky Street, Irkutsk 664033, Russian Federation
| | - Svetlana V Kirpichenko
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Division of the Russian Academy of Sciences , 1 Favorsky Street, Irkutsk 664033, Russian Federation
| | - Nina N Chipanina
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Division of the Russian Academy of Sciences , 1 Favorsky Street, Irkutsk 664033, Russian Federation
| | - Larisa P Oznobikhina
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Division of the Russian Academy of Sciences , 1 Favorsky Street, Irkutsk 664033, Russian Federation
| | - Erich Kleinpeter
- Chemisches Institut der Universität Potsdam , Karl-Liebknecht-Strasse 24-25, Potsdam (Golm) D-14476, Germany
| | - Sergey A Shlykov
- Ivanovo State University of Chemistry and Technology , Research Institute for Thermodynamics and Kinetics of Chemical Processes, Sheremetev avenue 7, Ivanovo 153000, Russian Federation
| | - Dmitriy Yu Osadchiy
- Ivanovo State University of Chemistry and Technology , Research Institute for Thermodynamics and Kinetics of Chemical Processes, Sheremetev avenue 7, Ivanovo 153000, Russian Federation
| |
Collapse
|
33
|
Garcias-Morales C, Ortegón-Reyna D, Ariza-Castolo A. Investigation of the role of stereoelectronic effects in the conformation of piperidones by NMR spectroscopy and X-ray diffraction. Beilstein J Org Chem 2015; 11:1973-84. [PMID: 26664617 PMCID: PMC4660988 DOI: 10.3762/bjoc.11.213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 10/01/2015] [Indexed: 12/28/2022] Open
Abstract
This paper reports the synthesis of a series of piperidones 1-8 by the Mannich reaction and analysis of their structures and conformations in solution by NMR and mass spectrometry. The six-membered rings in 2,4,6,8-tetraphenyl-3,7-diazabicyclo[3.3.1]nonan-9-ones, compounds 1 and 2, adopt a chair-boat conformation, while those in 2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-ones, compounds 3-8, adopt a chair-chair conformation because of stereoelectronic effects. These stereoelectronic effects were analyzed by the (1) J C-H coupling constants, which were measured in the (13)C satellites of the (1)H NMR spectra obtained with the hetero-dqf pulse sequence. In the solid state, these stereoelectronic effects were investigated by measurement of X-ray diffraction data, the molecular geometry (torsional bond angles and bond distances), and inter- and intramolecular interactions, and by natural bond orbital analysis, which was performed using density functional theory at the ωB97XD/6311++G(d,p) level. We found that one of the main factors influencing the conformational stability of 3-8 is the interaction between the lone-pair electrons of nitrogen and the antibonding sigma orbital of C(7)-Heq (nN→σ*C-H(7)eq), a type of hyperconjugative interaction.
Collapse
Affiliation(s)
- Cesar Garcias-Morales
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508 Colonia San Pedro Zacatenco, C.P. 07360, México, D.F., Mexico
| | - David Ortegón-Reyna
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508 Colonia San Pedro Zacatenco, C.P. 07360, México, D.F., Mexico
| | - Armando Ariza-Castolo
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508 Colonia San Pedro Zacatenco, C.P. 07360, México, D.F., Mexico
| |
Collapse
|
34
|
RETRACTED ARTICLE: Computational studies on the regioselectivity of metal-catalyzed synthesis of 1,2,3 triazoles via click reaction: a review. J Mol Model 2015; 21:264. [DOI: 10.1007/s00894-015-2810-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 08/30/2015] [Indexed: 01/06/2023]
|
35
|
Filloux CM. Das Problem der Ursachen und die Ursachen des Problems: Der Einfluss von Sprache auf Studien des anomeren Effekts. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201411185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
36
|
Filloux CM. The Problem of Origins and Origins of the Problem: Influence of Language on Studies Concerning the Anomeric Effect. Angew Chem Int Ed Engl 2015; 54:8880-94. [PMID: 26119827 DOI: 10.1002/anie.201411185] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 01/29/2015] [Indexed: 11/08/2022]
Abstract
Cause and effect: In science, language is often subordinated to empirical data, but words can influence our ability to understand and communicate science. This Essay argues that imprecise language has confounded studies that probe the interactions underlying the anomeric effect and related phenomena.
Collapse
Affiliation(s)
- Claire M Filloux
- Chemistry, Colorado State University, 1872 Campus Delivery, Fort Collins, CO 80523 (USA).
| |
Collapse
|
37
|
Lu P, Pakkala VS, Evanseck JD, Fleming FF. Metalated nitriles: S Ni' cyclizations with a propargylic electrophile. Tetrahedron Lett 2015; 56:3216-3219. [PMID: 26120212 PMCID: PMC4480775 DOI: 10.1016/j.tetlet.2015.01.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A rare 5-exo-dig SNi' cyclization with magnesiated and lithiated nitriles affords a cis-fused hydrindane bearing an exocyclic allene. The cyclization of the dilithiated nitrile pits a stereoelectronic preference for a trans-hydrindane against a cyclization through a less strained transition structure to the corresponding cis-hydrindane. Computational modeling suggests that the dilithiated nitrile cyclizes to a cis-hydrindane because the preferred transition structure positions the lithium cation in a cone of electron density that bridges the nitrile-bearing carbon, an alkoxide, and an electron-rich alkyne functionality.
Collapse
Affiliation(s)
- Ping Lu
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA
| | - Venkata S. Pakkala
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA
| | - Jeffrey D. Evanseck
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA
| | - Fraser F. Fleming
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA
| |
Collapse
|
38
|
Mohamed RK, Mondal S, Gold B, Evoniuk CJ, Banerjee T, Hanson K, Alabugin IV. Alkenes as Alkyne Equivalents in Radical Cascades Terminated by Fragmentations: Overcoming Stereoelectronic Restrictions on Ring Expansions for the Preparation of Expanded Polyaromatics. J Am Chem Soc 2015; 137:6335-49. [DOI: 10.1021/jacs.5b02373] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Rana K. Mohamed
- Florida State University, Tallahassee, Florida 32306, United States
| | - Sayantan Mondal
- Florida State University, Tallahassee, Florida 32306, United States
| | - Brian Gold
- Florida State University, Tallahassee, Florida 32306, United States
| | | | - Tanmay Banerjee
- Florida State University, Tallahassee, Florida 32306, United States
| | - Kenneth Hanson
- Florida State University, Tallahassee, Florida 32306, United States
| | - Igor V. Alabugin
- Florida State University, Tallahassee, Florida 32306, United States
| |
Collapse
|
39
|
Juaristi E, Notario R. Theoretical Examination of the S–C–P Anomeric Effect. J Org Chem 2015; 80:2879-83. [DOI: 10.1021/jo5029425] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Eusebio Juaristi
- Departamento
de Química, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, Apartado Postal 14-740, 07000 Mexico, D. F., México
| | - Rafael Notario
- Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain
| |
Collapse
|
40
|
Sutradhar D, Zeegers-Huyskens T, Chandra AK. Theoretical study of the interaction between pyridine derivatives and atomic chlorine. Substituent effect and nature of the bonding. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1014440] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
41
|
Weingand D, Kiefer C, Podlech J. Conformationally constrained 2-methylidene 1,3-oxathiane S-oxides: synthesis and nucleophilic additions. Tetrahedron 2015. [DOI: 10.1016/j.tet.2014.12.098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
42
|
Süveges BD, Podlech J. Dependence of Stereoelectronic and Charge Effects on pKaValues of 1,3-Dithiane-Derived Sulfides, Sulfoxides, and Sulfones: An Experimental and Computational Investigation. European J Org Chem 2014. [DOI: 10.1002/ejoc.201403409] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
|
43
|
Alabugin IV, Bresch S, dos Passos Gomes G. Orbital hybridization: a key electronic factor in control of structure and reactivity. J PHYS ORG CHEM 2014. [DOI: 10.1002/poc.3382] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Igor V. Alabugin
- Department of Chemistry and Biochemistry; Florida State University; Tallahassee FL 32306-4390 USA
| | - Stefan Bresch
- Department of Chemistry and Biochemistry; Florida State University; Tallahassee FL 32306-4390 USA
| | - Gabriel dos Passos Gomes
- Department of Chemistry and Biochemistry; Florida State University; Tallahassee FL 32306-4390 USA
| |
Collapse
|
44
|
Akhmetgareev AA, Bochkor SA, Kuznetsov VV. Conformational analysis of 3-methyltetrahydro-1,3-oxazine. RUSS J GEN CHEM+ 2014. [DOI: 10.1134/s1070363214100107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
45
|
Santos MF, Braga CB, Rozada TC, Basso EA, Fiorin BC. Rotational isomerism of some chloroacetamides: theoretical and experimental studies through calculations, infrared and NMR. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 129:148-156. [PMID: 24727174 DOI: 10.1016/j.saa.2014.02.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 02/04/2014] [Accepted: 02/19/2014] [Indexed: 06/03/2023]
Abstract
The geometries involved in the conformational equilibria of 2,2-dichloro-N-cyclohexyl-N-methyl-acetamide (DCCMA) and 2-chloro-N,N-dicyclohexylacetamide (CDCA) were investigated. Theoretical calculations at the B3LYP/cc-pVDZ level of theory showed that gauche forms (ClCCO) are the most stable and the predominant conformers in isolated phase. Both compounds had the conformational behavior in solvents of different polarities estimated from theoretical calculations with the PCM (Polarizable Continuum Model), at the same level of theory, using infrared data from deconvolution of the carbonyl absorption bands and (13)C NMR spectra. Their IR spectra showed two carbonyl absorptions and that the conformer with the highest dipole moment had its population increased when the most polar solvents were used, in accordance with the theoretical calculation in solution. (1)JCH coupling constants were obtained from their NMR spectra, and revealed that there was population variation of conformers with solvent exchange. Experimental data (NMR and IR) as well as calculations including the solvent effects followed the same trend.
Collapse
Affiliation(s)
- Marcela F Santos
- Departamento de Química, Universidade Estadual de Ponta Grossa/UEPG, Av. General Carlos Cavalcanti 4748, 84030-900 Ponta Grossa, PR, Brazil
| | - Carolyne B Braga
- Departamento de Química, Universidade Estadual de Ponta Grossa/UEPG, Av. General Carlos Cavalcanti 4748, 84030-900 Ponta Grossa, PR, Brazil
| | - Thiago C Rozada
- Departamento de Química, Universidade Estadual de Maringá/UEM, Av. Colombo 5790, 87020-900 Maringá, PR, Brazil
| | - Ernani A Basso
- Departamento de Química, Universidade Estadual de Maringá/UEM, Av. Colombo 5790, 87020-900 Maringá, PR, Brazil
| | - Barbara C Fiorin
- Departamento de Química, Universidade Estadual de Ponta Grossa/UEPG, Av. General Carlos Cavalcanti 4748, 84030-900 Ponta Grossa, PR, Brazil.
| |
Collapse
|
46
|
Silla JM, Freitas MP, Cormanich RA, Rittner R. The reverse fluorine Perlin-like effect and related stereoelectronic interactions. J Org Chem 2014; 79:6385-8. [PMID: 24904955 DOI: 10.1021/jo501025a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A similar effect to the well-known reverse Perlin effect was observed on the (1)JC-F coupling constants of α- and β-d-glucopyranosyl fluoride tetracetate, both in nonpolar and polar solution. This can be called "reverse fluorine Perlin-like effect", and it is shown to be ruled by dipolar interactions rather than by hyperconjugation. The reverse fluorine Perlin-like effect does not have a general relationship with the anomeric effect, and it can be useful to determine the structure and stereochemistry of organofluorine compounds.
Collapse
Affiliation(s)
- Josué M Silla
- Department of Chemistry, Federal University of Lavras , 37200-000, Lavras, Minas Gerais, Brazil
| | | | | | | |
Collapse
|
47
|
Mondal S, Gold B, Mohamed RK, Alabugin IV. Design of Leaving Groups in Radical CC Fragmentations: Through-Bond 2c-3e Interactions in Self-Terminating Radical Cascades. Chemistry 2014; 20:8664-9. [DOI: 10.1002/chem.201402843] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Indexed: 01/01/2023]
|
48
|
Alabugin IV, Bresch S, Manoharan M. Hybridization trends for main group elements and expanding the Bent's rule beyond carbon: more than electronegativity. J Phys Chem A 2014; 118:3663-77. [PMID: 24773162 DOI: 10.1021/jp502472u] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Trends in hybridization were systematically analyzed through the combination of DFT calculations with NBO analysis for the five elements X (X = B, C, N, O, and F) in 75 HnX-YHm compounds, where Y spans the groups 13-17 of the periods 2-4. This set of substrates probes the flexibility of the hybridization at five atoms X through variations in electronegativity, polarizability, and orbital size of Y. The results illustrate the scope and limitations of the Bent's rule, the classic correlation between electronegativity and hybridization, commonly used in analyzing structural effects in carbon compounds. The rehybridization effects are larger for fluorine- and oxygen-bonds than they are in the similar bonds to carbon. For bonds with the larger elements Y of the lower periods, trends in orbital hybridization depend strongly on both electronegativity and orbital size. For charged species, the effects of substituent orbital size in the more polarizable bonds to heavier elements show a particularly strong response to the charge introduction at the central atom. In the final section, we provide an example of the interplay between hybridization effects with molecular structure and reactivity. In particular, the ability to change hybridization without changes in polarization provides an alternative way to control structure and reactivity, as illustrated by the strong correlation of strain in monosubstituted cyclopropanes with hybridization in the bond to the substituent.
Collapse
Affiliation(s)
- Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306-4390, United States
| | | | | |
Collapse
|
49
|
Zeinalinezhad A, Sahnoun R, Aziz M. Ab initio molecular orbitals studies and NBO analysis of conformational preference in 2-hydroxypiperidine. COMPUT THEOR CHEM 2013. [DOI: 10.1016/j.comptc.2013.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
50
|
Lin JS, Jiang JC, Chang CM, Lai WW, Fang JW, Lin SH, Chang HC. Intermolecular Hydrogen Bonding and Structures in 1,3-Dioxane/D2O Mixtures Studied by High-Pressure Raman Spectroscopy. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200500089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|