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Triestram L, Falcioni F, Popelier PLA. Interacting Quantum Atoms and Multipolar Electrostatic Study of XH···π Interactions. ACS OMEGA 2023; 8:34844-34851. [PMID: 37779962 PMCID: PMC10535255 DOI: 10.1021/acsomega.3c04149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/31/2023] [Indexed: 10/03/2023]
Abstract
The interaction energies of nine XH···π (X = C, N, and O) benzene-containing van der Waals complexes were analyzed, at the atomic and fragment levels, using QTAIM multipolar electrostatics and the energy partitioning method interacting quantum atoms/fragment (IQA/IQF). These descriptors were paired with the relative energy gradient method, which solidifies the connection between quantum mechanical properties and chemical interpretation. This combination provides a precise understanding, both qualitative and quantitative, of the nature of these interactions, which are ubiquitous in biochemical systems. The formation of the OH···π and NH···π systems is electrostatically driven, with the Qzz component of the quadrupole moment of the benzene carbons interacting with the charges of X and H in XH. There is the unexpectedly intramonomeric role of X-H (X = O, N) where its electrostatic energy helps the formation of the complex and its covalent energy thwarts it. However, the CH···π interaction is governed by exchange-correlation energies, thereby establishing a covalent character, as opposed to the literature's designation as a noncovalent interaction. Moreover, dispersion energy is relevant, statically and in absolute terms, but less relevant compared to other energy components in terms of the formation of the complex. Multipolar electrostatics are similar across all systems.
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Affiliation(s)
- Lena Triestram
- Department of Chemistry, University
of Manchester, Manchester M13 9PL, Great
Britain
| | - Fabio Falcioni
- Department of Chemistry, University
of Manchester, Manchester M13 9PL, Great
Britain
| | - Paul L. A. Popelier
- Department of Chemistry, University
of Manchester, Manchester M13 9PL, Great
Britain
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2
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Stockerl WJ, Gschwind RM. Photo enhancement reveals ( E, Z) and ( Z, Z) configurations as additional intermediates in iminium ion catalysis. Chem Commun (Camb) 2023; 59:1325-1328. [PMID: 36644931 DOI: 10.1039/d2cc05976b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Imidazolidinone-based α,β-unsaturated iminium ions are the reactive species within countless synthetic protocols in asymmetric organocatalysis. However, (E,Z) and (Z,Z) imidazolidinone iminium ions, i.e. (Z)-CC configurations, have been elusive so far. Herein we describe how in situ photoisomerization enables the observation and assignment of high energetic (Z)-configured intermediates below the detection limit of NMR spectroscopy for (E,Z) and (Z,Z) iminium perchlorate complexes derived from MacMillan's 1st generation catalyst and cinnamaldehyde. Traces of (E,Z) could even be detected under synthetic conditions at 25 °C in MeCN. Using back isomerization studies and diffusion ordered spectroscopy, conditions were found to stabilize the (E,Z) and (Z,Z) isomers for several hours via ion pair aggregation. Thus, at least (E,Z) should be considered for future investigations in asymmetric iminium ion catalysis.
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Affiliation(s)
- Willibald J Stockerl
- Institute of Organic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
| | - Ruth M Gschwind
- Institute of Organic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
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3
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Costa AM, Cascales V, Castro-Alvarez A, Vilarrasa J. Computational Study of the Stability of Pyrrolidine-Derived Iminium Ions: Exchange Equilibria between Iminium Ions and Carbonyl Compounds. ACS OMEGA 2022; 7:18247-18258. [PMID: 35694469 PMCID: PMC9178767 DOI: 10.1021/acsomega.1c07020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
The tendency of carbonyl compounds to form iminium ions by reaction with pyrrolidine or chiral pyrrolidine derivatives (in other words, the relative stability to hydrolysis of these iminium ions) has been computationally examined, mainly using the M06-2X/6-311+G(d,p) method. We have thus obtained the equilibrium positions for R-CH=O + CH2=CH-CH=N+R2* → R-CH=N+R2* + CH2=CH-CH=O reactions and for related exchanges. In these exchanges, there is a transfer of a secondary amine between two carbonyl compounds. Their relative energies may be used to predict which iminium species can be predominantly formed when two or more carbonyl groups are present in a reaction medium. In the catalytic Michael additions of nucleophiles to iminium ions arising from conjugated enals, dienals, and trienals, if the formation of the new Nu-C bond is favorable, the chances of amino-catalyzed reactions to efficiently proceed, with high conversions, depend on the calculated energy values for these exchange equilibria, where the iminium tetrafluoroborates of the adducts (final iminium intermediates) must be more prone to hydrolysis than the initial iminium tetrafluoroborates. The density functional theory (DFT) calculations indicate that the MacMillan catalysts and related oxazolidinones are especially suitable in this regard.
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4
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Sansinenea E, Ortiz A. Asymmetric Organocatalytic Syntheses of Bioactive Compounds. Curr Org Synth 2022; 19:148-165. [DOI: 10.2174/1570179418666210728145206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/10/2021] [Accepted: 06/25/2021] [Indexed: 11/22/2022]
Abstract
Background:
The total syntheses of complex natural products have evolved to include new methodologies to save time, simplifying the form to achieve these natural compounds.
Objective:
In this review, we have described the asymmetric synthesis of different natural products and biologically active compounds of the last ten years until the current day.
Results:
An asymmetric organocatalytic reaction is a key to generate stereoselectively the main structure with the required stereochemistry.
Conclusion:
Even more remarkable, the organocatalytic cascade reactions, which are carried out with high stereoselectivity, as well as a possible approximation of the organocatalysts activation with sub-strates are also described.
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Affiliation(s)
- Estibaliz Sansinenea
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Aurelio Ortiz
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, México
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5
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Golub TP, Merten C. Vibrational CD study on the solution phase structures of the MacMillan catalyst and its corresponding iminium ion. Phys Chem Chem Phys 2021; 23:25162-25169. [PMID: 34730148 DOI: 10.1039/d1cp04497d] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We demonstrate that VCD spectroscopy can reveal insights into the conformational preferences of the iminium ion obtained from MacMillan's imidazolidinone catalyst. For both the isolated and in situ generated iminium ion, the comparison of experimental and computed VCD spectra directly confirms that conformer 2b ("Houk-conformer") is the dominant structure in solution. This conclusion is reached without any in-depth interpretation of the spectroscopic data, just by visual comparison of the spectral signatures. For the parent catalyst 1 and its salts 1·HCl and 1·HClO4, we report a comprehensive analysis of the conformational preferences in two solvents. VCD spectroscopy is subsequently shown to be able to reveal small conformational changes induced by solute-solvent and solute-anion interactions.
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Affiliation(s)
- Tino P Golub
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
| | - Christian Merten
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie II, Universitätsstraße 150, 44801 Bochum, Germany.
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6
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Hu J, Gao YQ, Xu D, Chen L, Wen W, Hou Y, Chen L, Xie W. Highly enantioselective addition of aliphatic aldehydes to 2-hydroxychalcone enabled by cooperative organocatalysts. Chem Commun (Camb) 2020; 56:10018-10021. [PMID: 32724997 DOI: 10.1039/d0cc04424e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Herein, we developed an enantioselective addition of aliphatic aldehydes to 2-hydroxychalcone promoted by cooperative organocatalysts, giving access to hybrid flavonoids in excellent enantioselectivities. This reaction took advantage of cycloisomerization of 2-hydroxychalcone to form a transient flavylium under the irradiation of 24 W CFL, which was trapped by the in situ generated chiral enamine intermediate. The synergistic action of chiral phosphoric acid secured the excellent outcome of this reaction by ion-pairing with the transient flavylium.
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Affiliation(s)
- Jiadong Hu
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, 22 Xinong Road, Yangling 712100, Shaanxi, China.
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7
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Maji R, Ugale H, Wheeler SE. Understanding the Reactivity and Selectivity of Fluxional Chiral DMAP-Catalyzed Kinetic Resolutions of Axially Chiral Biaryls. Chemistry 2019; 25:4452-4459. [PMID: 30657217 DOI: 10.1002/chem.201806068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/17/2019] [Indexed: 12/17/2022]
Abstract
Fluxional chiral DMAP-catalyzed kinetic resolutions of axially chiral biaryls were examined using density functional theory. Computational analyses lead to a revised understanding of this reaction in which the interplay of numerous non-covalent interactions control the conformation and flexibility of the active catalyst, the preferred mechanism, and the stereoselectivity. Notably, while the DMAP catalyst itself is confirmed to be highly fluxional, electrostatically driven π⋅⋅⋅π+ interactions render the active, acylated form of the catalyst highly rigid, explaining its pronounced stereoselectivity.
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Affiliation(s)
- Rajat Maji
- Department of Chemistry, Texas A&M University, College Station, TX, 77842, USA
| | - Heena Ugale
- Department of Chemistry, Texas A&M University, College Station, TX, 77842, USA
| | - Steven E Wheeler
- Department of Chemistry, Texas A&M University, College Station, TX, 77842, USA.,Center for Computational Quantum Chemistry, Department of Chemistry, University of Georgia, Athens, GA, 30602, USA
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8
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Affiliation(s)
- Shinji Yamada
- Department of Chemistry, Faculty of Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan
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9
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Aufiero M, Gilmour R. Informing Molecular Design by Stereoelectronic Theory: The Fluorine Gauche Effect in Catalysis. Acc Chem Res 2018; 51:1701-1710. [PMID: 29894155 DOI: 10.1021/acs.accounts.8b00192] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The axioms of stereoelectronic theory constitute an atlas to navigate the contours of molecular space. All too rarely lauded, the advent and development of stereoelectronic theory has been one of organic chemistry's greatest triumphs. Inevitably, however, in the absence of a comprehensive treatise, many of the field's pioneers do not receive the veneration that they merit. Rather their legacies are the stereoelectronic pillars that persist in teaching and research. This ubiquity continues to afford practitioners of organic chemistry with an abundance of opportunities for creative endeavor in reaction design, in conceiving novel activation modes, in preorganizing intermediates, or in stabilizing productive transition states and products. Antipodal to steric governance, which mitigates destabilizing nonbonding interactions, stereoelectronic control allows well-defined, often complementary, conformations to be populated. Indeed, the prevalence of stabilizing hyperconjugative interactions in biosynthetic processes renders this approach to molecular preorganization decidedly biomimetic and, by extension, expansive. In this Account, the evolution and application of a simple donor-acceptor model based on the fluorine gauche effect is delineated. Founded on reinforcing hyperconjugative interactions involving C(sp3)-H bonding orbitals and C(sp3)-X antibonding orbitals [σC-H → σC-X*], this general stratagem has been used in conjunction with an array of secondary noncovalent interactions to achieve acyclic conformational control (ACC) in structures of interest. These secondary effects range from 1,3-allylic strain (A1,3) through to electrostatic charge-dipole and cation-π interactions. Synergy between these interactions ensures that rotation about strategic C(sp3)-C(sp3) bonds is subject to the stereoelectronic requirement for antiperiplanarity (180°). Logically, in a generic [X-CH2-CH2-Y] system (X, Y = electron withdrawing groups) conformations in which the two C(sp3)-X bonds are synclinal (i.e., gauche) are significantly populated. As such, simple donor-acceptor models are didactically and predictively powerful in achieving topological preorganization. In the case of the gauche effect, the low steric demand of fluorine ensures that the remaining substituents at the C(sp3) hybridized center are placed in a predictable area of molecular space: An exit vector analogy is thus appropriate. Furthermore, the intrinsic chemical stability of the C-F bond is advantageous, thus it may be considered as an inert conformational steering group: This juxtaposition of size and electronegativity renders fluorinated organic molecules unique among the organo-halogen series. Cognizant that the replacement of one fluorine atom in the difluoroethylene motif by another electron withdrawing group preserves the gauche conformation, it was reasoned that β-fluoroamines would be intriguing candidates for investigation. The burgeoning field of Lewis base catalysis, particularly via iminium ion activation, provided a timely platform from which to explore a postulated fluorine-iminium ion gauche effect. Necessarily, activation of this stereoelectronic effect requires a process of intramolecularization to generate the electron deficient neighboring group: Examples include protonation, condensation to generate iminium salts, or acylation. This process, akin to substrate binding, has obvious parallels with enzymatic catalysis, since it perturbs the conformational dynamics of the system [ synclinal-endo, antiperiplanar, synclinal-exo]. This Account details the development of conformationally predictable small molecules based on the [X-Cα-Cβ-F] motif through a logical process of molecular design and illustrates their synthetic value in enantioselective catalysis.
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Affiliation(s)
- Marialuisa Aufiero
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany
| | - Ryan Gilmour
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany
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10
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11
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Orlandi M, Hilton MJ, Yamamoto E, Toste FD, Sigman MS. Mechanistic Investigations of the Pd(0)-Catalyzed Enantioselective 1,1-Diarylation of Benzyl Acrylates. J Am Chem Soc 2017; 139:12688-12695. [PMID: 28800230 PMCID: PMC5649438 DOI: 10.1021/jacs.7b06917] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A mechanistic study of the Pd-catalyzed enantioselective 1,1-diarylation of benzyl acrylates that is facilitated by a chiral anion phase transfer (CAPT) process is presented. Kinetic analysis, labeling, competition, and nonlinear effect experiments confirm the hypothesized general mechanism and reveal the role of the phosphate counterion in the CAPT catalysis. The phosphate was found to be involved in the phase transfer step and in the stereoinduction process, as expected, but also in the unproductive reaction that provides the traditional Heck byproduct. Multivariate correlations revealed the CAPT catalyst's structural features, affecting the production of this undesired byproduct, as well as weak interactions responsible for enantioselectivity. Such putative interactions include π-stacking and a CH···O electrostatic attraction between the substrate benzyl moiety and the phosphate. Analysis of the computed density functional theory transition structures for the stereodetermining step of the reaction supports the multivariate model obtained. The presented work provides the first comprehensive study of the combined use of CAPT and transition metal catalysis, setting the foundation for future applications.
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Affiliation(s)
- Manuel Orlandi
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, USA
| | - Margaret J. Hilton
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, USA
| | - Eiji Yamamoto
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, USA
| | - F. Dean Toste
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Matthew S. Sigman
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, USA
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12
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Maji R, Wheeler SE. Importance of Electrostatic Effects in the Stereoselectivity of NHC-Catalyzed Kinetic Resolutions. J Am Chem Soc 2017; 139:12441-12449. [DOI: 10.1021/jacs.7b01796] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Rajat Maji
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Steven E. Wheeler
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
- Center
for Computational Quantum Chemistry, Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
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13
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van der Mei FW, Qin C, Morrison RJ, Hoveyda AH. Practical, Broadly Applicable, α-Selective, Z-Selective, Diastereoselective, and Enantioselective Addition of Allylboron Compounds to Mono-, Di-, Tri-, and Polyfluoroalkyl Ketones. J Am Chem Soc 2017. [PMID: 28648084 DOI: 10.1021/jacs.7b05011] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A practical method for enantioselective synthesis of fluoroalkyl-substituted Z-homoallylic tertiary alcohols has been developed. Reactions may be performed with ketones containing a polylfluoro-, trifluoro-, difluoro-, and monofluoroalkyl group along with an aryl, a heteroaryl, an alkenyl, an alkynyl, or an alkyl substituent. Readily accessible unsaturated organoboron compounds serve as reagents. Transformations were performed with 0.5-2.5 mol % of a boron-based catalyst, generated in situ from a readily accessible valine-derived aminophenol and a Z- or an E-γ-substituted boronic acid pinacol ester. With a Z organoboron reagent, additions to trifluoromethyl and polyfluoroalkyl ketones proceeded in 80-98% yield, 97:3 to >98:2 α:γ selectivity, >95:5 Z:E selectivity, and 81:19 to >99:1 enantiomeric ratio. In notable contrast to reactions with unsubstituted allylboronic acid pinacol ester, additions to ketones with a mono- or a difluoromethyl group were highly enantioselective as well. Transformations were similarly efficient and α- and Z-selective when an E-allylboronate compound was used, but enantioselectivities were lower. In certain cases, the opposite enantiomer was favored (up to 4:96 er). With a racemic allylboronate reagent that contains an allylic stereogenic center, additions were exceptionally α-selective, affording products expected from γ-addition of a crotylboron compound, in up to 97% yield, 88:12 diastereomeric ratio, and 94:6 enantiomeric ratio. Utility is highlighted by gram-scale preparation of representative products through transformations that were performed without exclusion of air or moisture and through applications in stereoselective olefin metathesis where Z-alkene substrates are required. Mechanistic investigations aided by computational (DFT) studies and offer insight into different selectivity profiles.
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Affiliation(s)
- Farid W van der Mei
- Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States
| | - Changming Qin
- Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States
| | - Ryan J Morrison
- Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States
| | - Amir H Hoveyda
- Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States
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14
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Affiliation(s)
| | - Penchala Latha
- School of Chemistry; University of Hyderabad; Hyderabad India
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15
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Kennedy CR, Lin S, Jacobsen EN. The Cation-π Interaction in Small-Molecule Catalysis. Angew Chem Int Ed Engl 2016; 55:12596-624. [PMID: 27329991 PMCID: PMC5096794 DOI: 10.1002/anie.201600547] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Indexed: 11/11/2022]
Abstract
Catalysis by small molecules (≤1000 Da, 10(-9) m) that are capable of binding and activating substrates through attractive, noncovalent interactions has emerged as an important approach in organic and organometallic chemistry. While the canonical noncovalent interactions, including hydrogen bonding, ion pairing, and π stacking, have become mainstays of catalyst design, the cation-π interaction has been comparatively underutilized in this context since its discovery in the 1980s. However, like a hydrogen bond, the cation-π interaction exhibits a typical binding affinity of several kcal mol(-1) with substantial directionality. These properties render it attractive as a design element for the development of small-molecule catalysts, and in recent years, the catalysis community has begun to take advantage of these features, drawing inspiration from pioneering research in molecular recognition and structural biology. This Review surveys the burgeoning application of the cation-π interaction in catalysis.
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Affiliation(s)
- C Rose Kennedy
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA, 02138, USA
| | - Song Lin
- Department of Chemistry, University of California, Berkeley, 535 Latimer Hall, Berkeley, CA, 94720, USA
| | - Eric N Jacobsen
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA, 02138, USA.
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Seegerer A, Hioe J, Hammer MM, Morana F, Fuchs PJW, Gschwind RM. Remote-Stereocontrol in Dienamine Catalysis: Z-Dienamine Preferences and Electrophile-Catalyst Interaction Revealed by NMR and Computational Studies. J Am Chem Soc 2016; 138:9864-73. [PMID: 27430865 DOI: 10.1021/jacs.6b04008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Catalysis with remote-stereocontrol provides special challenges in design and comprehension. One famous example is the dienamine catalysis, for which high ee values are reported despite insufficient shielding of the second double bond. Especially for dienamines with variable Z/E-ratios of the second double bond, no correlations to the ee values are found. Therefore, the structures, thermodynamics, and kinetics of dienamine intermediates in SN-type reactions are investigated. The NMR studies show that the preferred dienamine conformation provides an effective shielding if large electrophiles are used. Calculations at SCS-MP2/CBS-level of theory and experimental data of the dienamine formation show kinetic preference for the Z-isomer of the second double bond and a slow isomerization toward the thermodynamically preferred E-isomer. Modulations of the rate-determining step, by variation of the concentration of the electrophile, allow the conversion of dienamines to be observed. With electrophiles, a faster reaction of Z- than of E-isomers is observed experimentally. Calculations corroborate these results by correlating ee values of three catalysts with the kinetics of the electrophilic attack and reveal the significance of CH-π and stacking interactions in the transition states. Thus, for the first time a comprehensive understanding of the remote stereocontrol in γ-functionalization reactions of dienamines and an explanation to the "Z/E-dilemma" are presented. The combination of bulky catalyst subsystems and large electrophiles provides a shielding of one face and causes different reactivities of E/Z-dienamines in nucleophilic attacks from the other face. Kinetic preferences for the formation of Z-dienamines and their unfavorable thermodynamics support high ee values.
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Affiliation(s)
- Andreas Seegerer
- Institut für Organische Chemie, Universität Regensburg , D-93053 Regensburg, Germany
| | - Johnny Hioe
- Institut für Organische Chemie, Universität Regensburg , D-93053 Regensburg, Germany
| | - Michael M Hammer
- Institut für Organische Chemie, Universität Regensburg , D-93053 Regensburg, Germany
| | - Fabio Morana
- Institut für Organische Chemie, Universität Regensburg , D-93053 Regensburg, Germany
| | - Patrick J W Fuchs
- Institut für Organische Chemie, Universität Leipzig , D-04103 Leipzig, Germany
| | - Ruth M Gschwind
- Institut für Organische Chemie, Universität Regensburg , D-93053 Regensburg, Germany
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17
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Kennedy CR, Lin S, Jacobsen EN. Die Kation-π-Wechselwirkung in der Katalyse mit niedermolekularen Verbindungen. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201600547] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- C. Rose Kennedy
- Department of Chemistry and Chemical Biology; Harvard University; 12 Oxford St Cambridge MA 02138 USA
| | - Song Lin
- Department of Chemistry; University of California, Berkeley; 535 Latimer Hall Berkeley CA 94720 USA
| | - Eric N. Jacobsen
- Department of Chemistry and Chemical Biology; Harvard University; 12 Oxford St Cambridge MA 02138 USA
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18
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Bräuer TM, Zhang Q, Tiefenbacher K. Iminium Catalysis inside a Self-Assembled Supramolecular Capsule: Modulation of Enantiomeric Excess. Angew Chem Int Ed Engl 2016; 55:7698-701. [DOI: 10.1002/anie.201602382] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/22/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Thomas M. Bräuer
- Department of Chemistry; Technical University of Munich; Lichtenbergstrasse 4 85747 Garching Germany
| | - Qi Zhang
- Department of Chemistry; Technical University of Munich; Lichtenbergstrasse 4 85747 Garching Germany
| | - Konrad Tiefenbacher
- Department of Chemistry; University of Basel; St. Johannsring 19 CH-4056 Basel Switzerland
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19
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Bräuer TM, Zhang Q, Tiefenbacher K. Iminiumkatalyse in einer selbstorganisierten supramolekularen Kapsel: Modulation des Enantiomerenüberschusses. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201602382] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Thomas M. Bräuer
- Department Chemie; Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Qi Zhang
- Department Chemie; Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Konrad Tiefenbacher
- Departement Chemie; Universität Basel; St. Johannsring 19 CH-4056 Basel Schweiz
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20
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Miros FN, Zhao Y, Sargsyan G, Pupier M, Besnard C, Beuchat C, Mareda J, Sakai N, Matile S. Enolate Stabilization by Anion-π Interactions: Deuterium Exchange in Malonate Dilactones on π-Acidic Surfaces. Chemistry 2015; 22:2648-57. [DOI: 10.1002/chem.201504008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Indexed: 01/04/2023]
Affiliation(s)
- François N. Miros
- Department of Organic Chemistry; University of Geneva; Geneva Switzerland), Fax
| | - Yingjie Zhao
- Department of Organic Chemistry; University of Geneva; Geneva Switzerland), Fax
- Institute of Polymers; ETH Zurich; Zurich Switzerland
- Qingdao University of Science and Technology; P. R. China
| | - Gevorg Sargsyan
- Department of Organic Chemistry; University of Geneva; Geneva Switzerland), Fax
- South Texas College; McAllen Texas USA
| | - Marion Pupier
- Department of Organic Chemistry; University of Geneva; Geneva Switzerland), Fax
| | - Céline Besnard
- Department of Organic Chemistry; University of Geneva; Geneva Switzerland), Fax
| | - César Beuchat
- Department of Organic Chemistry; University of Geneva; Geneva Switzerland), Fax
- AKYADO; Remaufens Switzerland
| | - Jiri Mareda
- Department of Organic Chemistry; University of Geneva; Geneva Switzerland), Fax
| | - Naomi Sakai
- Department of Organic Chemistry; University of Geneva; Geneva Switzerland), Fax
| | - Stefan Matile
- Department of Organic Chemistry; University of Geneva; Geneva Switzerland), Fax
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21
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Zhao Y, Benz S, Sakai N, Matile S. Selective acceleration of disfavored enolate addition reactions by anion-π interactions. Chem Sci 2015; 6:6219-6223. [PMID: 30090238 PMCID: PMC6054047 DOI: 10.1039/c5sc02563j] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 08/05/2015] [Indexed: 01/17/2023] Open
Abstract
In chemistry and biology, cation-π interactions contribute significantly to many important transformations. In sharp contrast, reactions accomplished with support from the complementary anion-π interactions are essentially unknown. In this report, we show that anion-π interactions can determine the selectivity of the enolate chemistry of malonate half thioesters. Their addition to enolate acceptors is central in natural product biosynthesis but fails without enzymes because non-productive decarboxylation dominates. The newly designed and synthesized anion-π tweezers invert this selectivity by accelerating the disfavored and decelerating the favored process. The discrimination of anionic tautomers of different planarization and charge delocalization on π-acidic surfaces is expected to account for this intriguing "tortoise-and-hare catalysis." Almost exponentially increasing selectivity with increasing π acidity of the catalyst supports that contributions from anion-π interactions are decisive.
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Affiliation(s)
- Yingjie Zhao
- Department of Organic Chemistry , University of Geneva , Geneva , Switzerland . ; http://www.unige.ch/sciences/chiorg/matile/ ; ; Tel: +41 22 379 6523
| | - Sebastian Benz
- Department of Organic Chemistry , University of Geneva , Geneva , Switzerland . ; http://www.unige.ch/sciences/chiorg/matile/ ; ; Tel: +41 22 379 6523
| | - Naomi Sakai
- Department of Organic Chemistry , University of Geneva , Geneva , Switzerland . ; http://www.unige.ch/sciences/chiorg/matile/ ; ; Tel: +41 22 379 6523
| | - Stefan Matile
- Department of Organic Chemistry , University of Geneva , Geneva , Switzerland . ; http://www.unige.ch/sciences/chiorg/matile/ ; ; Tel: +41 22 379 6523
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22
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Zhao Y, Cotelle Y, Avestro AJ, Sakai N, Matile S. Asymmetric Anion-π Catalysis: Enamine Addition to Nitroolefins on π-Acidic Surfaces. J Am Chem Soc 2015; 137:11582-5. [DOI: 10.1021/jacs.5b07382] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Yingjie Zhao
- Department
of Organic Chemistry, University of Geneva, Geneva CH-1211, Switzerland
| | - Yoann Cotelle
- Department
of Organic Chemistry, University of Geneva, Geneva CH-1211, Switzerland
| | - Alyssa-Jennifer Avestro
- Department
of Organic Chemistry, University of Geneva, Geneva CH-1211, Switzerland
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Naomi Sakai
- Department
of Organic Chemistry, University of Geneva, Geneva CH-1211, Switzerland
| | - Stefan Matile
- Department
of Organic Chemistry, University of Geneva, Geneva CH-1211, Switzerland
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23
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Fujisawa K, Humbert-Droz M, Letrun R, Vauthey E, Wesolowski TA, Sakai N, Matile S. Ion Pair−π Interactions. J Am Chem Soc 2015; 137:11047-56. [DOI: 10.1021/jacs.5b05593] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Kaori Fujisawa
- School of Chemistry and Biochemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Marie Humbert-Droz
- School of Chemistry and Biochemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Romain Letrun
- School of Chemistry and Biochemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Eric Vauthey
- School of Chemistry and Biochemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Tomasz A. Wesolowski
- School of Chemistry and Biochemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Naomi Sakai
- School of Chemistry and Biochemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Stefan Matile
- School of Chemistry and Biochemistry, University of Geneva, CH-1211 Geneva, Switzerland
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24
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Holland MC, Metternich JB, Daniliuc C, Schweizer WB, Gilmour R. Aromatic Interactions in Organocatalyst Design: Augmenting Selectivity Reversal in Iminium Ion Activation. Chemistry 2015; 21:10031-8. [PMID: 25982418 DOI: 10.1002/chem.201500270] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Indexed: 12/12/2022]
Abstract
Substituting N-methylpyrrole for N-methyindole in secondary-amine-catalysed Friedel-Crafts reactions leads to a curious erosion of enantioselectivity. In extreme cases, this substrate dependence can lead to an inversion in the sense of enantioinduction. Indeed, these closely similar transformations require two structurally distinct catalysts to obtain comparable selectivities. Herein a focussed molecular editing study is disclosed to illuminate the structural features responsible for this disparity, and thus identify lead catalyst structures to further exploit this selectivity reversal. Key to effective catalyst re-engineering was delineating the non-covalent interactions that manifest themselves in conformation. Herein we disclose preliminary validation that intermolecular aromatic (CH-π and cation-π) interactions between the incipient iminium cation and the indole ring system is key to rationalising selectivity reversal. This is absent in the N-methylpyrrole alkylation, thus forming the basis of two competing enantio-induction pathways. A simple L-valine catalyst has been developed that significantly augments this interaction.
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Affiliation(s)
- Mareike C Holland
- Institut für Organische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster (Germany) http://www.uni-muenster.de/Chemie.oc/gilmour/,Current address: Department of Chemistry and Biochemistry, University of California Los Angeles, 607 Charles E. Young Drive East, Los Angeles 90095-1569 (USA)
| | - Jan Benedikt Metternich
- Institut für Organische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster (Germany) http://www.uni-muenster.de/Chemie.oc/gilmour/
| | - Constantin Daniliuc
- Institut für Organische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster (Germany) http://www.uni-muenster.de/Chemie.oc/gilmour/
| | - W Bernd Schweizer
- Laboratorium für Organische Chemie, ETH Zürich, Vladimir-Prelog-Weg 3, 8093 Zürich (Switzerland)
| | - Ryan Gilmour
- Institut für Organische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster (Germany) http://www.uni-muenster.de/Chemie.oc/gilmour/. .,Excellence Cluster EXC 1003 "Cells in Motion", Westfälische Wilhelms-Universität Münster, Münster (Germany).
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