1
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Nordquist EB, Jia Z, Chen J. Small Molecule NS11021 Promotes BK Channel Activation by Increasing Inner Pore Hydration. J Chem Inf Model 2024. [PMID: 39264311 DOI: 10.1021/acs.jcim.4c01012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2024]
Abstract
The Ca2+ and voltage-gated big potassium (BK) channels are implicated in various diseases, including heart disease, asthma, epilepsy, and cancer, but remain an elusive drug target. A class of negatively charged activators (NCAs) have been demonstrated to promote the activation of several potassium channels including BK channels by binding to the hydrophobic inner pore, yet the underlying molecular mechanism of action remains poorly understood. In this work, we analyze the binding mode and potential activation mechanism of a specific NCA named NS11021 using atomistic simulations. The results show that NS11021 binding to the pore in deactivated BK channels is nonspecific and dynamic. The binding free energy of -8.3 ± 0.7 kcal/mol (KD = 0.3-3.1 μM) calculated using umbrella sampling agrees quantitatively with the experimental EC50 range of 0.4-2.1 μM. The bound NS11021 remains dynamic and is distal from the filter to significantly impact its conformation. Instead, NS11021 binding significantly enhances the pore hydration due to the charged tetrazol-phenyl group, thereby promoting the opening of the hydrophobic gate. We further show that the free energy barrier to K+ permeation is reduced by ∼3 kcal/mol regardless of the binding pose, which could explain the ∼62-fold increase in the intrinsic opening of BK channels measured experimentally. Taken together, these results support the idea that the molecular mechanism of NS11021 derives from increasing the hydration level of the conformationally closed pore, which does not depend on specific binding and likely explains the ability of NCAs to activate multiple K+ channels.
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Affiliation(s)
- Erik B Nordquist
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Zhiguang Jia
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
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2
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Fragkiadakis M, Thomaidi M, Stergiannakos T, Chatziorfanou E, Gaidatzi M, Michailidis Barakat A, Stoumpos C, Neochoritis CG. High Rotational Barrier Atropisomers. Chemistry 2024; 30:e202401461. [PMID: 38962895 DOI: 10.1002/chem.202401461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 07/03/2024] [Accepted: 07/04/2024] [Indexed: 07/05/2024]
Abstract
Atropisomers have attracted a great deal of attention lately due to their numerous applications in organic synthesis and to their employment in drug discovery. However, the synthetic arsenal at our disposal with which to access them remains limited. The research described herein is two-pronged; we both demonstrate the use of MCR chemistry as a synthetic strategy for the de novo synthesis of a class of atropisomers having high barriers to rotation with the simultaneous insertion of multiple chiral elements and we study these unprecedented molecular systems by employing a combination of crystallography, NMR and DFT calculations. By fully exploiting the synthetic capabilities of our chemistry, we have been able to monitor a range of different types of interaction, i. e. π-π, CH-π, heteroatom-π and CD-π, in order to conduct structure-property studies. The results could be applied both to atroposelective synthesis and in drug discovery.
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Affiliation(s)
| | - Maria Thomaidi
- Department of Chemistry, University of Crete, Voutes, Heraklion, 70013, Greece
| | | | | | - Maria Gaidatzi
- Department of Chemistry, University of Crete, Voutes, Heraklion, 70013, Greece
| | | | - Constantinos Stoumpos
- Department of Materials Science & Technology, University of Crete, Voutes, Heraklion, 70013, Greece
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3
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Kovács B, Földes T, Szabó M, Dorkó É, Kótai B, Laczkó G, Holczbauer T, Domján A, Pápai I, Soós T. Illuminating the multiple Lewis acidity of triaryl-boranes via atropisomeric dative adducts. Chem Sci 2024:d4sc00925h. [PMID: 39257854 PMCID: PMC11382148 DOI: 10.1039/d4sc00925h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 08/23/2024] [Indexed: 09/12/2024] Open
Abstract
Using the principle that constrained conformational spaces can generate novel and hidden molecular properties, we challenged the commonly held perception that a single-centered Lewis acid reacting with a single-centered Lewis base always forms a single Lewis adduct. Accordingly, the emergence of single-centered but multiple Lewis acidity among sterically hindered and non-symmetric triaryl-boranes is reported. These Lewis acids feature several diastereotopic faces providing multiple binding sites at the same Lewis acid center in the interaction with Lewis bases giving rise to adducts with diastereomeric structures. We demonstrate that with a proper choice of the base, atropisomeric adduct species can be formed that interconvert via the dissociative mechanism rather than conformational isomerism. The existence of this exotic and peculiar molecular phenomenon was experimentally confirmed by the formation of atropisomeric piperidine-borane adducts using state-of-the-art NMR techniques in combination with computational methods.
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Affiliation(s)
- Benjámin Kovács
- Centre for Structural Science, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Tamás Földes
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Márk Szabó
- Centre for Structural Science, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Éva Dorkó
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Bianka Kótai
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Gergely Laczkó
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
- Hevesy György PhD School of Chemistry, Eötvös Loránd University P. O. Box 32 Budapest H-1518 Hungary
| | - Tamás Holczbauer
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Attila Domján
- Centre for Structural Science, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Imre Pápai
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
| | - Tibor Soós
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences Magyar tudósok körútja 2 H-1117 Budapest Hungary
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4
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Kitagawa O. Structural Chemistry of C-N Axially Chiral Compounds. J Org Chem 2024; 89:11089-11099. [PMID: 39087953 DOI: 10.1021/acs.joc.4c01065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024]
Abstract
In the last several years, atropisomers owing to the rotational restriction around a C-N single bond (C-N axially chiral compounds) have attracted significant attention in the field of synthetic organic chemistry. In particular, the highly enantioselective synthesis of various C-N axially chiral compounds and their application to asymmetric reactions have been reported by many groups. On the other hand, studies on the structural chemistry of C-N axially chiral compounds have attracted scant attention in comparison with synthetic studies. For over 25 years, our group has explored asymmetric synthesis of C-N axially chiral compounds and their synthetic application. In the course of these synthetic studies, we found several notable structural properties in relation to the C-N bond rotation and an association of enantiomers (the relationship between the rotational stability and the structure or electronic effect, the chirality-dependent halogen bond, and the self-disproportionation of enantiomers). Furthermore, on the basis of these structural properties, the development of acid-mediated molecular rotors and the synthesis of isotopic atropisomers possessing high stereochemical purity and rotational stability were achieved. Through this Perspective, I wish to make the chemistry community aware that C-N axially chiral compounds are attractive molecules from the viewpoints of both synthetic organic chemistry and structural chemistry.
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Affiliation(s)
- Osamu Kitagawa
- Chemistry and Materials Program, College of Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Kohto-ku, Tokyo, 135-8548, Japan
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5
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Naghim A, Rodriguez J, Chuzel O, Chouraqui G, Bonne D. Enantioselective Synthesis of Heteroatom-Linked Non-Biaryl Atropisomers. Angew Chem Int Ed Engl 2024; 63:e202407767. [PMID: 38748462 DOI: 10.1002/anie.202407767] [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: 04/24/2024] [Indexed: 06/16/2024]
Abstract
Atropisomers hold significant fascination, not only for their prevalence in natural compounds but also for their biological importance and wide-ranging applications as chiral materials, ligands, and organocatalysts. While biaryl and heterobiaryl atropisomers are commonly studied, the enantioselective synthesis of less abundant heteroatom-linked non-biaryl atropisomers presents a formidable challenge in modern organic synthesis. Unlike classical atropisomers, these molecules allow rotation around two bonds, resulting in low barriers to enantiomerization through concerted bond rotations. In recent years the discovery of new configurationally stable rare non-biaryl scaffolds such as aryl amines, aryl ethers and aryl sulfones as well as innovative methodologies to control their configuration have been disclosed in the literature and constitute the topic of this minireview.
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Affiliation(s)
- Abdelati Naghim
- Aix Marseille Université, CNRS, Centrale Méditerranée, iSm2, 13397, Marseille, France
| | - Jean Rodriguez
- Aix Marseille Université, CNRS, Centrale Méditerranée, iSm2, 13397, Marseille, France
| | - Olivier Chuzel
- Aix Marseille Université, CNRS, Centrale Méditerranée, iSm2, 13397, Marseille, France
| | - Gaëlle Chouraqui
- Aix Marseille Université, CNRS, Centrale Méditerranée, iSm2, 13397, Marseille, France
| | - Damien Bonne
- Aix Marseille Université, CNRS, Centrale Méditerranée, iSm2, 13397, Marseille, France
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6
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Campbell ADG, Roper NJ, Waddell PG, Wills C, Dixon CM, Denton RM, Ermanis K, Armstrong RJ. Synthesis, structure and stereodynamics of atropisomeric N-chloroamides. Chem Commun (Camb) 2024; 60:3818-3821. [PMID: 38494914 DOI: 10.1039/d4cc00268g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Atropisomeric N-chloroamides were efficiently accessed by electrophilic halogenation of ortho-substituted secondary anilides. The stereodynamics of atropisomerism in these novel scaffolds was interrogated by detailed experimental and computational studies, revealing that racemization is correlated with amide isomerization. The stereoelectronic nature of the amide was shown to significantly influence racemization rates, with potentially important implications for other C-N atropisomeric scaffolds.
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Affiliation(s)
- Aaron D G Campbell
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
| | - Natalie J Roper
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
| | - Paul G Waddell
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
| | - Corinne Wills
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
| | - Casey M Dixon
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
| | - Ross M Denton
- School of Chemistry, University Park, Nottingham, UK.
| | | | - Roly J Armstrong
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
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7
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Feng J, Lu CJ, Liu RR. Catalytic Asymmetric Synthesis of Atropisomers Featuring an Aza Axis. Acc Chem Res 2023; 56:2537-2554. [PMID: 37694726 DOI: 10.1021/acs.accounts.3c00419] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
ConspectusAtropisomers bearing a rotation-restricted axis are common structural units in natural products, chiral ligands, and drugs; thus, the prevalence of asymmetric synthesis has increased in recent decades. Research into atropisomers featuring an N-containing axis (N-X atropisomers) remains in its infancy compared with the well-developed C-C atropisomer analogue. Notably, N-X atropisomers could offer divergent scaffolds, which are extremely important in bioactive molecules. The asymmetric synthesis of N-X atropisomers is recognized as both appealing and challenging. Recently, we devoted our efforts to the catalytic asymmetric synthesis of N-X atropisomers, benzimidazole-aryl N-C atropisomers, indole-aryl N-C atropisomers, hydrogen-bond-assisted N-C atropisomers, pyrrole-pyrrole N-N atropisomers, pyrrole-indole N-N atropisomers, and indole-indole N-N atropisomers. To obtain the N-C atropisomers, an asymmetric Buchwald-Hartwig reaction of amidines or enamines was employed. Using a Pd(OAc)2/(S)-BINAP or Pd(OAc)2/(S)-Xyl-BINAP catalyst system, benzimidazole-aryl N-C atropisomers and indole-aryl N-C atropisomers were readily obtained. To address the issue of the reduced stability of the diarylamine axis, a six-membered intramolecular N-H-O hydrogen bond was introduced into the N-C atropisomer scaffold. A tandem N-arylation/oxidation process was used for the chiral phosphoric acid (CPA)-catalyzed asymmetric synthesis of N-aryl quinone atropisomers. For N-N atropisomers, a copper-mediated asymmetric Friedel-Crafts alkylation/arylation reaction was developed. The desymmetrization process was completed successfully via a Cu(OTf)2/chiral bisoxazoline or (CuOTf)·Tol/bis(phosphine) dioxide system, thereby achieving the first catalytic asymmetric synthesis of N/N bipyrrole atropisomers. Asymmetric Buchwald-Hartwig amination of enamines was utilized to provide N-N bisindole atropisomers with excellent stereogenic control. This was the first asymmetric synthesis of N-N atropisomers featuring a bisindole structural scaffold using the de novo indole construction strategy. The asymmetric N-N heterobiaryl atropisomer synthesis was substantially facilitated using palladium-catalyzed transient directing group (TDG)-mediated C-H functionalization. Atropisomeric alkenylation, allylation, or alkynylation was accomplished using the Pd(OAc)2/l-tert-leucine system. Herein, we summarize our work on the palladium-, copper-, and CPA-catalyzed asymmetric syntheses of N-C and N-N atropisomers. Furthermore, the application of our work in the synthesis of bioactive molecule analogues and axially chiral ligands is demonstrated. Subsequently, the stability of the chiral N-containing axis is briefly discussed in terms of single crystals and obtained rotational barriers. Finally, an outlook on the asymmetric N-X atropisomer synthesis is provided.
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Affiliation(s)
- Jia Feng
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China
| | - Chuan-Jun Lu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China
| | - Ren-Rong Liu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China
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8
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Heeb JP, Clayden J, Smith MD, Armstrong RJ. Interrogating the configurational stability of atropisomers. Nat Protoc 2023; 18:2745-2771. [PMID: 37542183 DOI: 10.1038/s41596-023-00859-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 05/05/2023] [Indexed: 08/06/2023]
Abstract
Atropisomers are molecules whose stereogenicity arises from restricted rotation about a single bond. They are of current importance because of their applications in catalysis, medicine and materials science. The defining feature of atropisomeric molecules is that their stereoisomers are related to one another by bond rotation: as a result, evaluating their configurational stability (i.e., the rate at which their stereoisomers interconvert) is central to any work in this area. Important atropisomeric scaffolds include C-C linked biaryls, such as the ligand BINAP and the drug vancomycin, and C-N linked amine derivatives such as the drug telenzepine. This article focuses on the three most widely used experimental methods that are available to measure the rate of racemization in atropisomers, namely: (i) kinetic analysis of the racemization of an enantioenriched sample, (ii) dynamic HPLC and (iii) variable-temperature NMR. For each technique, an explanation of the theory is set out, followed by a detailed experimental procedure. A discussion is also included of which technique to try when confronted with a new molecular structure whose properties are not yet known. None of the three procedures require complex experimental techniques, and all can be performed by using standard analytical equipment (NMR and HPLC). The time taken to determine a racemization rate depends on which experimental method is required, but for a new compound it is generally possible to measure a racemization rate in <1 d.
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Affiliation(s)
| | | | - Martin D Smith
- Chemistry Research Laboratory, University of Oxford, Oxford, UK.
| | - Roly J Armstrong
- School of Natural and Environmental Sciences (Chemistry), Newcastle University, Newcastle Upon Tyne, UK.
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9
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Singhania A, Chatterjee S, Kalita S, Saha S, Chettri P, Gayen FR, Saha B, Sahoo P, Bandyopadhyay A, Ghosh S. An Inbuilt Electronic Pawl Gates Orbital Information Processing and Controls the Rotation of a Double Ratchet Rotary Motor. ACS APPLIED MATERIALS & INTERFACES 2023; 15:15595-15604. [PMID: 36926805 DOI: 10.1021/acsami.3c01103] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
A direct external input energy source (e.g., light, chemical reaction, redox potential, etc.) is compulsory to supply energy to rotary motors for accomplishing rotation around the axis. The stator leads the direction of rotation, and a sustainable rotation requires two mutual input energy supplies (e.g., light and heat, light and pH or metal ion, etc.); however, there are some exceptions (e.g., covalent single bond rotors and/or motors). On the contrary, our experiment suggested that double ratchet rotary motors (DRMs) can harvest power from available thermal noise, kT, for sustainable rotation around the axis. Under a scanning tunneling microscope, we have imaged live thermal noise movement as a dynamic orbital density and resolved the density diagram up to the second derivative. A second input energy can synchronize multiple rotors to afford a measurable output. Therefore, we hypothesized that rotation control in a DRM must be evolved from an orbital-level information transport channel between the two coupled rotors but was not limited to the second input energy. A DRM comprises a Brownian rotor and a power stroke rotor coupled to a -C≡C- stator, where the transport of information through coupled orbitals between the two rotors is termed the vibrational information flow chain (VIFC). We test this hypothesis by studying the DRM's density functional theory calculation and variable-temperature 1H nuclear magnetic resonance. Additionally, we introduced inbuilt pawl-like functional moieties into a DRM to create different electronic environments by changing proton intercalation interactions, which gated information processing through the VIFC. The results show the VIFC can critically impact the motor's noise harvesting, resulting in variable rotational motions in DRMs.
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Affiliation(s)
- Anup Singhania
- Natural Product Chemistry Group, Chemical Sciences & Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, Assam, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Satadru Chatterjee
- Natural Product Chemistry Group, Chemical Sciences & Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, Assam, India
| | - Sudeshna Kalita
- Natural Product Chemistry Group, Chemical Sciences & Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, Assam, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Supriya Saha
- Advanced Computation & Data Sciences Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, Assam, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- Green Engineered Materials and Additive Manufacturing Division, CSIR-AMPRI, 462026 Bhopal, Madhya Pradesh, India
| | - Prerna Chettri
- Natural Product Chemistry Group, Chemical Sciences & Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, Assam, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Firdaus Rahaman Gayen
- Advanced Materials Group, Material Sciences & Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, Assam, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Biswajit Saha
- Advanced Materials Group, Material Sciences & Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, Assam, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Pathik Sahoo
- International Center for Materials and Nanoarchitectronics (MANA) and Research Center for Advanced Measurement and Characterization (RCAMC), National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 3050047, Japan
| | - Anirban Bandyopadhyay
- International Center for Materials and Nanoarchitectronics (MANA) and Research Center for Advanced Measurement and Characterization (RCAMC), National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 3050047, Japan
| | - Subrata Ghosh
- Natural Product Chemistry Group, Chemical Sciences & Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, Assam, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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10
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Thönnißen V, Atodiresei IL, Patureau FW. Atroposelective Nenitzescu Indole Synthesis. Chemistry 2023; 29:e202300279. [PMID: 36725685 DOI: 10.1002/chem.202300279] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/03/2023]
Abstract
In the past decade, compounds bearing a stereogenic C-N axis have gained significant attention in fields ranging from ligand to drug design. Yet, the atroposelective synthesis of these molecules remains a considerable challenge. In contrast to recent methods using more advanced chiral catalysts, a very simply accessed Jacobsen-type chromium(III)-salen complex was used here as a chiral enantiopure Lewis acid catalyst for a highly atroposelective Nenitzescu indole synthesis. Mild reaction conditions afforded various 5-hydroxybenzo[g]indoles in up to 97 % yield. Moreover, through a simple work-up, very high enantiomeric excesses of up to 99 % could be obtained.
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Affiliation(s)
- Vinzenz Thönnißen
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Iuliana L Atodiresei
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Frederic W Patureau
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
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11
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Watts OB, Berreur J, Collins BSL, Clayden J. Biocatalytic Enantioselective Synthesis of Atropisomers. Acc Chem Res 2022; 55:3362-3375. [PMID: 36343339 PMCID: PMC9730853 DOI: 10.1021/acs.accounts.2c00572] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Atropisomeric compounds are found extensively as natural products, as ligands for asymmetric transition-metal catalysis, and increasingly as bioactive and pharmaceutically relevant targets. Their enantioselective synthesis is therefore an important ongoing research target. While a vast majority of known atropisomeric structures are (hetero)biaryls, which display hindered rotation around a C-C single bond, our group's long-standing interest in the control of molecular conformation has led to the identification and stereoselective preparation of a variety of other classes of "nonbiaryl" atropisomeric compounds displaying restricted rotation around C-C, C-N, C-O, and C-S single bonds.Biocatalytic transformations are finding increasing application in both academic and industrial contexts as a result of a significant broadening of the range of biocatalytic reactions and sources of enzymes available to the synthetic chemist. In this Account, we summarize the main biocatalytic strategies currently available for the asymmetric synthesis of biaryl, heterobiaryl, and nonbiaryl atropisomers. As is the case with more traditional synthetic approaches to these compounds, most biocatalytic methodologies for the construction of enantioenriched atropisomers follow one of two distinct strategies. The first of these is the direct asymmetric construction of atropisomeric bonds. Synthetically applicable biocatalytic methodologies for this type of transformation are limited, despite the extensive research into the biosynthesis of (hetero)biaryls by oxidative homocoupling or cross-coupling of electron-rich arenes. The second of these is the asymmetric transformation of a molecule in which the bond that will form the axis already exists, and this approach represents the majority of biocatalytic strategies available to the synthetic organic chemist. This strategy encompasses a variety of stereoselective techniques including kinetic resolution (KR), desymmetrization, dynamic kinetic resolution (DKR), and dynamic kinetic asymmetric transformation (DYKAT).Nondynamic kinetic resolution (KR) of conformationally stable biaryl derivatives has provided the earliest and most numerous examples of synthetically useful methodologies for the enantioselective preparation of atropisomeric compounds. Lipases (i.e., enzymes that mediate the formation or hydrolysis of esters) are particularly effective and have attracted broad attention. This success has led researchers to broaden the scope of lipase-mediated transformations to desymmetrization reactions, in addition to a limited number of DKR and DYKAT examples. By contrast, our group has used redox enzymes, including an engineered galactose oxidase (GOase) and commercially available ketoreductases (KREDs), to desymmetrize prochiral atropisomeric diaryl ether and biaryl derivatives. Building on this experience and our long-standing interest in dynamic conformational processes, we later harnessed intramolecular noncovalent interactions to facilitate bond rotation at ambient temperatures, which allowed the development of the efficient DKR of heterobiaryl aldehydes using KREDs. With this Account we provide an overview of the current and prospective biocatalytic strategies available to the synthetic organic chemist for the enantioselective preparation of atropisomeric molecules.
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12
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Abstract
Atropisomerism is a conformational chirality that occurs when there is hindered rotation about a σ-bond. While atropisomerism is exemplified by biaryls, it is observed in many other pharmaceutically relevant scaffolds including heterobiaryls, benzamides, diarylamines, and anilides. As bond rotation leads to racemization, atropisomers span the gamut of stereochemical stability. LaPlante has classified atropisomers based on their half-life of racemization at 37 °C: class 1 (t1/2 < 60 s), class 2 (60 s < t1/2 < 4.5 years), and class 3 (t1/2 > 4.5 years). In general, class-3 atropisomers are considered to be suitable for drug development. There are currently four FDA-approved drugs that exist as stable atropisomers, and many others are in clinical trials or have recently appeared in the drug discovery literature. Class-1 atropisomers are more prevalent, with ∼30% of recent FDA-approved small molecules possessing at least one class-1 axis. While class-1 atropisomers do not possess the requisite stereochemical stability to meet the classical definition of atropisomerism, they often bind a given target in a specific set of chiral conformations.Over the past decade, our laboratory has embarked on a research program aimed at leveraging atropisomerism as a design feature to improve the target selectivity of promiscuous lead compounds. Our studies initially focused on introducing class-3 atropisomerism into promiscuous kinase inhibitors, resulting in a proof of principle in which the different atropisomers of a compound can have different selectivity profiles with potentially improved target selectivity. This inspired a careful analysis of the binding conformations of diverse ligands bound to different target proteins, resulting in the realization that the sampled dihedral conformations about a prospective atropisomeric axis played a key role in target binding and that preorganizing the prospective atropisomeric axis into a desired target's preferred conformational range can lead to large gains in target selectivity.As atropisomerism is becoming more prevalent in modern drug discovery, there is an increasing need for strategies for atropisomerically pure samples of pharmaceutical compounds. This has led us and other groups to develop catalytic atroposelective methodologies toward pharmaceutically privileged scaffolds. Our laboratory has contributed examples of atroposelective methodologies toward heterobiaryl systems while also exploring the chirality of less-studied atropisomers such as diarylamines and related scaffolds.This Account will detail recent encounters with atropisomerism in medicinal chemistry and how atropisomerism has transitioned from a "lurking menace" into a leverageable design strategy in order to modulate various properties of biologically active small molecules. This Account will also discuss recent advances in atroposelective synthesis, with a focus on methodologies toward pharmaceutically privileged scaffolds. We predict that a better understanding of the effects of conformational restriction about a prospective atropisomeric axis on target binding will empower chemists to rapidly "program" the selectivity of a lead molecule toward a desired target.
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13
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Mondal A, Toyoda R, Costil R, Feringa BL. Chemically Driven Rotatory Molecular Machines. Angew Chem Int Ed Engl 2022; 61:e202206631. [PMID: 35852813 PMCID: PMC9826306 DOI: 10.1002/anie.202206631] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Indexed: 01/11/2023]
Abstract
Molecular machines are at the frontier of biology and chemistry. The ability to control molecular motion and emulating the movement of biological systems are major steps towards the development of responsive and adaptive materials. Amazing progress has been seen for the design of molecular machines including light-induced unidirectional rotation of overcrowded alkenes. However, the feasibility of inducing unidirectional rotation about a single bond as a result of chemical conversion has been a challenging task. In this Review, an overview of approaches towards the design, synthesis, and dynamic properties of different classes of atropisomers which can undergo controlled switching or rotation under the influence of a chemical stimulus is presented. They are categorized as molecular switches, rotors, motors, and autonomous motors according to their type of response. Furthermore, we provide a future perspective and challenges focusing on building sophisticated molecular machines.
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Affiliation(s)
- Anirban Mondal
- Stratingh Institute for Chemistry University of GroningenNijenborgh 49747 AGGroningenThe Netherlands
| | - Ryojun Toyoda
- Stratingh Institute for Chemistry University of GroningenNijenborgh 49747 AGGroningenThe Netherlands
- Department of ChemistryGraduate School of ScienceTohoku University6-3 Aramaki-Aza-AobaAobaku, Sendai980-8578Japan
| | - Romain Costil
- Stratingh Institute for Chemistry University of GroningenNijenborgh 49747 AGGroningenThe Netherlands
| | - Ben L. Feringa
- Stratingh Institute for Chemistry University of GroningenNijenborgh 49747 AGGroningenThe Netherlands
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14
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Arroyo‐Córdoba IJ, Gamboa‐Velázquez G, Avila‐Ortiz CG, Leyva‐Ramírez MA, Cortez‐Picasso MT, García‐Revilla MA, Ramírez‐Ornelas DE, Peña‐Cabrera E, Juaristi E. Structure and Conformation of Novel BODIPY Ugi Adducts. ChemistryOpen 2022; 11:e202200197. [PMID: 36284210 PMCID: PMC9596608 DOI: 10.1002/open.202200197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 09/22/2022] [Indexed: 11/20/2022] Open
Abstract
Two novel BODIPY-Ugi (boron dipyrromethene) adducts exhibit peculiar room temperature (T=20 °C) H-1 NMR spectra in that several protons located at the aromatic aniline-type ring are lost in the baseline. This observation revealed the existence of a dynamic conformational process where rotation around the C-N bond is hindered. Variable-temperature H-1 and C-13 NMR spectroscopic analysis confirmed this conclusion; that is, low-temperature spectra show distinct signals for all four aromatic protons below coalescence, whereas average signals are recorded above coalescence (T=+120 °C). Particularly interesting was the rather large difference in chemical shifts for the ortho protons below coalescence, Δδ=1.45 ppm, which was explained based on DFT computational analysis. Indeed, the calculated lowest-energy gas-phase conformation of the BODIPY Ugi adducts locates one half of the aniline-type ring in the shielding anisotropic cone of the bridge phenyl ring in the BODIPY segment. This is in contrast to the solid-state conformation established by X-ray diffraction analysis that shows a nearly parallel arrangement of the aromatic rings, probably induced by crystal packing forces.
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Affiliation(s)
- Ismael Javier Arroyo‐Córdoba
- Department of ChemistryCentro de Investigación y de Estudios AvanzadosAvenida IPN 2508 San Pedro Zacatenco07360Ciudad de MéxicoMexico
| | - Gonzalo Gamboa‐Velázquez
- Department of ChemistryCentro de Investigación y de Estudios AvanzadosAvenida IPN 2508 San Pedro Zacatenco07360Ciudad de MéxicoMexico
| | - Claudia Gabriela Avila‐Ortiz
- Department of ChemistryCentro de Investigación y de Estudios AvanzadosAvenida IPN 2508 San Pedro Zacatenco07360Ciudad de MéxicoMexico
| | - Marco A. Leyva‐Ramírez
- Department of ChemistryCentro de Investigación y de Estudios AvanzadosAvenida IPN 2508 San Pedro Zacatenco07360Ciudad de MéxicoMexico
| | - María Teresa Cortez‐Picasso
- Department of ChemistryCentro de Investigación y de Estudios AvanzadosAvenida IPN 2508 San Pedro Zacatenco07360Ciudad de MéxicoMexico
| | | | | | - Eduardo Peña‐Cabrera
- Department of ChemistryUniversidad de Guanajuato Noria Alta S/N36050Guanajuato, Gto.Mexico
| | - Eusebio Juaristi
- Department of ChemistryCentro de Investigación y de Estudios AvanzadosAvenida IPN 2508 San Pedro Zacatenco07360Ciudad de MéxicoMexico
- El Colegio NacionalLuis González Obregón 23 Centro Histórico06020Ciudad de MéxicoMexico
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15
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Zhu D, Yu L, Luo H, Xue X, Chen Z. Atroposelective Electrophilic Sulfenylation of
N
‐Aryl Aminoquinone Derivatives Catalyzed by Chiral SPINOL‐Derived Sulfide. Angew Chem Int Ed Engl 2022; 61:e202211782. [DOI: 10.1002/anie.202211782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Deng Zhu
- School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong University Shanghai 200240 P. R. China
| | - Lu Yu
- College of Chemistry Nankai University Tianjin 300071 P. R. China
- Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences Shanghai 200032 P. R. China
| | - Hui‐Yun Luo
- School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong University Shanghai 200240 P. R. China
| | - Xiao‐Song Xue
- Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences Shanghai 200032 P. R. China
- School of Chemistry and Materials Science Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences 1 Sub-lane Xiangshan Hangzhou 310024 P. R. China
| | - Zhi‐Min Chen
- School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong University Shanghai 200240 P. R. China
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16
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Zhu D, Yu L, Luo HY, Xue XS, Chen ZM. Atroposelective Electrophilic Sulfenylation of N‐Aryl Aminoquinone Derivatives Catalyzed by Chiral SPINOL‐Derived Sulfide. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202211782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Deng Zhu
- Shanghai Jiao Tong University School of Chemistry and Chemical Engineering CHINA
| | - Lu Yu
- Nankai University college of chemistry 94 Weijin Road, Nankai District 300071 CHINA
| | - Hui-Yun Luo
- Shanghai Jiao Tong University School of Chemistry and Chemical Engineering CHINA
| | - Xiao-Song Xue
- Shanghai Institute of Organic Chemistry Key Laboratory of Organofluorine Chemistry CHINA
| | - Zhi-Min Chen
- Shanghai Jiao Tong University School of Chemistry and Chemical Engineering 800 Dongchuan RD. Minhang District 200240 Shanghai CHINA
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17
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Mondal A, Toyoda R, Costil R, Feringa BL. Chemically Driven Rotatory Molecular Machines. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anirban Mondal
- University of Groningen: Rijksuniversiteit Groningen Stratingh Institute for Chemistry NETHERLANDS
| | - Ryojun Toyoda
- University of Groningen: Rijksuniversiteit Groningen Stratingh Institute for Chmistry NETHERLANDS
| | - Romain Costil
- University of Groningen: Rijksuniversiteit Groningen Stratingh Institute for Chemistry NETHERLANDS
| | - Ben L Feringa
- University of Groningen Stratingh Institute for Chemistry, Faculty of Science and Engineering Nijenborgh 4 9747 AG Groningen NETHERLANDS
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18
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Homma D, Taketani S, Shirai T, Caytan E, Roussel C, Elguero J, Alkorta I, Kitagawa O. Rotational Behavior of N-(5-Substituted-pyrimidin-2-yl)anilines: Relayed Electronic Effect in Two N-Ar Bond Rotations. J Org Chem 2022; 87:8118-8125. [PMID: 35657258 DOI: 10.1021/acs.joc.2c00845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
N-Methyl-2-methoxymethylanilines 1 bearing various 5-substituted-pyrimidin-2-yl groups were prepared, and their rotational behaviors were explored in detail. It was revealed that the rotational barriers around two N-Ar bonds increase in proportion to the electron-withdrawing ability of substituents X at the 5-position.
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Affiliation(s)
- Daiki Homma
- Department of Applied Chemistry (Japanese Association of Bio-intelligence for Well-being), Shibaura Institute of Technology, 3-7-5 Toyosu, Kohto-ku, Tokyo 135-8548, Japan
| | - Shuhei Taketani
- Department of Applied Chemistry (Japanese Association of Bio-intelligence for Well-being), Shibaura Institute of Technology, 3-7-5 Toyosu, Kohto-ku, Tokyo 135-8548, Japan
| | - Takeshi Shirai
- Department of Applied Chemistry (Japanese Association of Bio-intelligence for Well-being), Shibaura Institute of Technology, 3-7-5 Toyosu, Kohto-ku, Tokyo 135-8548, Japan
| | - Elsa Caytan
- Univ Rennes, CNRS, ISCR - UMR 6226, F-35000 Rennes, France
| | - Christian Roussel
- Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397 Cedex 20 Marseille, France
| | - José Elguero
- Instituto de Química Médica, CSIC, Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - Ibon Alkorta
- Instituto de Química Médica, CSIC, Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - Osamu Kitagawa
- Department of Applied Chemistry (Japanese Association of Bio-intelligence for Well-being), Shibaura Institute of Technology, 3-7-5 Toyosu, Kohto-ku, Tokyo 135-8548, Japan
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19
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Vaidya SD, Heydari BS, Toenjes ST, Gustafson JL. Approaches toward Atropisomerically Stable and Conformationally Pure Diarylamines. J Org Chem 2022; 87:6760-6768. [PMID: 35486501 PMCID: PMC9799075 DOI: 10.1021/acs.joc.2c00451] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Diarylamines possess two potentially atropisomeric C-N axes; however, there are few examples of atropisomerically stable diarylamines in the literature, as the contiguous axes can allow for low energy racemization pathways via concerted bond rotations. Herein, we describe highly atropisomerically stable diarylamines that possess barriers to racemization of 30-36 kcal/mol, corresponding to half-lives to racemization on the decade to century time scale at room temperature. Investigation of the factors that led to the high stereochemical stability suggests that increased conjugation of the aniline lone pair of electrons into a more electron-deficient aryl ring, coupled with intramolecular hydrogen-bonding, locked the corresponding axis into a defined planar conformation, disfavoring the lower energy racemization pathways.
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Affiliation(s)
- Sagar D. Vaidya
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030, United States
| | - Beeta S. Heydari
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030, United States
| | - Sean T. Toenjes
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030, United States
| | - Jeffrey L. Gustafson
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030, United States
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20
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Gao Y, Liao Q, Li M, Han M, Huang A, Dang Q, Li Q, Li Z. Expounding the Relationship between Molecular Conformation and Room-Temperature Phosphorescence Property by Deviation Angle. J Phys Chem Lett 2022; 13:3251-3260. [PMID: 35388692 DOI: 10.1021/acs.jpclett.2c00597] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Room-temperature phosphorescence (RTP) emitters with ultralong lifetimes are attracting more and more attention for their wide applications. However, it is still a big challenge to achieve persistent organic afterglow because of the undefined relationship between molecular structures and RTP effect. Herein, diphenylamine (DPA) as a commonly used building block is selected as the molecular skeleton. Through incorporation of various alkyl moieties by ortho-substitution in different numbers and positions, RTP lifetimes can increase from 129 to 661 ms with the subtle adjustment of molecular conformations. It is summarized that the deviation angle (θ) of phenyl units in the DPA skeleton from the ideal p-π conjugated plane can act as the key parameter determining RTP lifetime, and the larger the θ values, the longer the RTP lifetimes. Furthermore, this result has been successfully applied as the universal principle to explain the RTP properties of various organic luminogens with DPA blocks and similar structures.
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Affiliation(s)
- Yuan Gao
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Qiuyan Liao
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Menghan Li
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Mengmeng Han
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Arui Huang
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Qianxi Dang
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Qianqian Li
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Zhen Li
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, P.R. China
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21
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Chirality-matched catalyst-controlled macrocyclization reactions. Proc Natl Acad Sci U S A 2021; 118:2113122118. [PMID: 34599107 DOI: 10.1073/pnas.2113122118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2021] [Indexed: 11/18/2022] Open
Abstract
Macrocycles, formally defined as compounds that contain a ring with 12 or more atoms, continue to attract great interest due to their important applications in physical, pharmacological, and environmental sciences. In syntheses of macrocyclic compounds, promoting intramolecular over intermolecular reactions in the ring-closing step is often a key challenge. Furthermore, syntheses of macrocycles with stereogenic elements confer an additional challenge, while access to such macrocycles are of great interest. Herein, we report the remarkable effect peptide-based catalysts can have in promoting efficient macrocyclization reactions. We show that the chirality of the catalyst is essential for promoting favorable, matched transition-state relationships that favor macrocyclization of substrates with preexisting stereogenic elements; curiously, the chirality of the catalyst is essential for successful reactions, even though no new static (i.e., not "dynamic") stereogenic elements are created. Control experiments involving either achiral variants of the catalyst or the enantiomeric form of the catalyst fail to deliver the macrocycles in significant quantity in head-to-head comparisons. The generality of the phenomenon, demonstrated here with a number of substrates, stimulates analogies to enzymatic catalysts that produce naturally occurring macrocycles, presumably through related, catalyst-defined peripheral interactions with their acyclic substrates.
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22
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Murugesan T, Sivarajan C, Jayakumari CM, Singh RK, Vennapusa SR, Kaliyamoorthy A. Palladium-Catalyzed Direct C2-Biarylation of Indoles. J Org Chem 2021; 86:10838-10851. [PMID: 34291945 DOI: 10.1021/acs.joc.1c01123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biaryl and indole units are important structural motifs in several bioactive molecules and functional materials. We have accomplished straightforward access to C2-biarylated indole derivatives through palladium-catalyzed C-H activation strategy with a broad range of substrate scope in yields of 24 to 92%. Besides, the UV/visible absorption and fluorescence properties of the ensuing products were explored. The calculated higher dihedral angle and rotational barrier values for the selected C2-biarylated indoles show that these compounds may display atropisomerism at room temperature.
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Affiliation(s)
- Tamilarasu Murugesan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Kerala 695551, India
| | - Chinraj Sivarajan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Kerala 695551, India
| | - Chithra Mohan Jayakumari
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Kerala 695551, India
| | - Rajat Kumar Singh
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Kerala 695551, India
| | - Sivaranjana Reddy Vennapusa
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Kerala 695551, India
| | - Alagiri Kaliyamoorthy
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Kerala 695551, India
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23
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Abstract
The atroposelective formation of C-N bonds has recently emerged within the field of amination reactions. On first sight, it may seem quite surprising that such an ancient class of organic coupling reactions (Gabriel, Ullmann, Goldberg, Buchwald, Hartwig and many others) has so few enantioselective solutions, and this in spite of asymmetric synthesis being now a mature concept and field. Why should enantioselective C-N bond formation be so difficult? This question and some of the first examples that promise an imminent change of paradigm are herein discussed.
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Affiliation(s)
- Vinzenz Thönnißen
- Institute of Organic ChemistryRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Frederic W. Patureau
- Institute of Organic ChemistryRWTH Aachen UniversityLandoltweg 152074AachenGermany
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24
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Barik S, Shee S, Das S, Gonnade RG, Jindal G, Mukherjee S, Biju AT. NHC‐Catalyzed Desymmetrization of N‐Aryl Maleimides Leading to the Atroposelective Synthesis of N‐Aryl Succinimides. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016938] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Soumen Barik
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Sayan Shee
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Soumik Das
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Rajesh G. Gonnade
- Centre for Materials Characterization CSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pune 411008 India
| | - Garima Jindal
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Subrata Mukherjee
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Akkattu T. Biju
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
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25
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Barik S, Shee S, Das S, Gonnade RG, Jindal G, Mukherjee S, Biju AT. NHC‐Catalyzed Desymmetrization of N‐Aryl Maleimides Leading to the Atroposelective Synthesis of N‐Aryl Succinimides. Angew Chem Int Ed Engl 2021; 60:12264-12268. [DOI: 10.1002/anie.202016938] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/04/2021] [Indexed: 12/11/2022]
Affiliation(s)
- Soumen Barik
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Sayan Shee
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Soumik Das
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Rajesh G. Gonnade
- Centre for Materials Characterization CSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pune 411008 India
| | - Garima Jindal
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Subrata Mukherjee
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
| | - Akkattu T. Biju
- Department of Organic Chemistry Indian Institute of Science Bangalore 560012 India
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26
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Tóth BL, Monory A, Egyed O, Domján A, Bényei A, Szathury B, Novák Z, Stirling A. The ortho effect in directed C-H activation. Chem Sci 2021; 12:5152-5163. [PMID: 34163752 PMCID: PMC8179598 DOI: 10.1039/d1sc00642h] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 02/20/2021] [Indexed: 12/12/2022] Open
Abstract
The success of transition metal-catalysed ortho-directed C-H activation is often plagued by the effects of undesirable interactions between the directing group (DG) and other groups introduced into the aromatic core of the substrate. In particular, when these groups are in neighbouring positions, their interactions can affect profoundly the efficacy of the C-H activation by transition metals. In this work we introduce a simple substrate-only-based model to interpret the influence of steric hindrance of a group in ortho position to the DG in directed ortho-C-H bond activation reactions, and coined the term Ortho Effect (OE) for such situations. We consider simple descriptors such as torsion angle and torsional energy to predict and explain the reactivity of a given substrate in directed C-H activation reactions. More than 250 examples have been invoked for the model, and the nature of the ortho effect was demonstrated on a wide variety of structures. In order to guide organic chemists, we set structural and energetic criteria to evaluate a priori the efficiency of the metalation step which is usually the rate-determining event in C-H activations, i.e. we provide a simple and general protocol to estimate the reactivity of a potential substrate in C-H activation. For borderline cases these criteria help set the minimum reaction temperature to obtain reasonable reaction rates. As an example for the practical applicability of the model, we performed synthetic validations via palladium-catalysed 2,2,2-trifluoroethylation reactions in our lab. Furthermore, we give predictions for the necessary reaction conditions for several selected DGs.
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Affiliation(s)
- Balázs L Tóth
- ELTE "Lendület" Catalysis and Organic Synthesis Research Group, Faculty of Science, Institute of Chemistry, Eötvös Loránd University Pázmány Péter Sétány. 1/A H-1117 Budapest Hungary
| | - Anna Monory
- ELTE "Lendület" Catalysis and Organic Synthesis Research Group, Faculty of Science, Institute of Chemistry, Eötvös Loránd University Pázmány Péter Sétány. 1/A H-1117 Budapest Hungary
| | - Orsolya Egyed
- Research Centre for Natural Sciences, Eötvös Loránd Research Network Magyar Tudósok Körútja 2 H-1117 Budapest Hungary
| | - Attila Domján
- Research Centre for Natural Sciences, Eötvös Loránd Research Network Magyar Tudósok Körútja 2 H-1117 Budapest Hungary
| | - Attila Bényei
- Department of Physical Chemistry, University of Debrecen Egyetem Tér 1 H-4032 Debrecen Hungary
| | - Bálint Szathury
- Department of Chemistry, University of Cambridge Lensfield Rd Cambridge CB2 1EW UK
| | - Zoltán Novák
- ELTE "Lendület" Catalysis and Organic Synthesis Research Group, Faculty of Science, Institute of Chemistry, Eötvös Loránd University Pázmány Péter Sétány. 1/A H-1117 Budapest Hungary
| | - András Stirling
- Research Centre for Natural Sciences, Eötvös Loránd Research Network Magyar Tudósok Körútja 2 H-1117 Budapest Hungary
- Department of Chemistry, Eszterházy Károly University Leányka u. 6 H-3300 Eger Hungary
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Franzini R, Pierini M, Mazzanti A, Iazzetti A, Ciogli A, Villani C. Molecular Recognition of the HPLC Whelk-O1 Selector towards the Conformational Enantiomers of Nevirapine and Oxcarbazepine. Int J Mol Sci 2020; 22:ijms22010144. [PMID: 33375681 PMCID: PMC7796420 DOI: 10.3390/ijms22010144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/16/2020] [Accepted: 12/23/2020] [Indexed: 01/19/2023] Open
Abstract
The presence of stereogenic elements is a common feature in pharmaceutical compounds, and affording optically pure stereoisomers is a frequent issue in drug design. In this context, the study of the chiral molecular recognition mechanism fundamentally supports the understanding and optimization of chromatographic separations with chiral stationary phases. We investigated, with molecular docking, the interactions between the chiral HPLC selector Whelk-O1 and the stereoisomers of two bioactive compounds, the antiviral Nevirapine and the anticonvulsant Oxcarbazepine, both characterized by two stereolabile conformational enantiomers. The presence of fast-exchange enantiomers and the rate of the interconversion process were studied using low temperature enantioselective HPLC and VT-NMR with Whelk-O1 applied as chiral solvating agent. The values of the energetic barriers of interconversion indicate, for the single enantiomers of both compounds, half-lives sufficiently long enough to allow their separation only at critically sub-ambient temperatures. The chiral selector Whelk-O1 performed as a strongly selective discriminating agent both when applied as a chiral stationary phase (CSP) in HPLC and as CSA in NMR spectroscopy.
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Affiliation(s)
- Roberta Franzini
- Department of Chemistry and Technology of Drugs, “Department of Excellence 2018−2022”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (M.P.); (A.I.); (A.C.)
- Correspondence: (R.F.); (C.V.)
| | - Marco Pierini
- Department of Chemistry and Technology of Drugs, “Department of Excellence 2018−2022”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (M.P.); (A.I.); (A.C.)
| | - Andrea Mazzanti
- Dipartimento di Chimica Industriale “Toso Montanari”, Università di Bologna, V. Risorgimento 4, 40136 Bologna, Italy;
| | - Antonia Iazzetti
- Department of Chemistry and Technology of Drugs, “Department of Excellence 2018−2022”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (M.P.); (A.I.); (A.C.)
| | - Alessia Ciogli
- Department of Chemistry and Technology of Drugs, “Department of Excellence 2018−2022”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (M.P.); (A.I.); (A.C.)
| | - Claudio Villani
- Department of Chemistry and Technology of Drugs, “Department of Excellence 2018−2022”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (M.P.); (A.I.); (A.C.)
- Correspondence: (R.F.); (C.V.)
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