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Fu MX, Lin JH, Xiao JC. Desulfurization of Thiols for Nucleophilic Substitution. Org Lett 2024; 26:6065-6069. [PMID: 38984702 DOI: 10.1021/acs.orglett.4c02256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Although the desulfurization of thiols is a topic of great importance and has received significant attention, most efforts have focused on the hydrodesulfurization of thiols. In this work, we describe the desulfurization of thiols for nucleophilic substitution. This process occurs rapidly, promoted by the Ph3P/ICH2CH2I system, and can be extended to a wide range of nucleophiles. Notably, free amines can be employed as nucleophiles to synthesize various secondary and tertiary amines. This method tolerates a wide array of functional groups, including hydroxyl groups in amination reactions. Benzyl thiols are particularly reactive and can be completely converted at room temperature within 15 min. Although alkyl thiols show lower reactivity, they can also be converted smoothly at a reaction temperature of 70 °C overnight.
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Affiliation(s)
- Mu-Xian Fu
- Department of Chemistry, Innovative Drug Research Center, Shanghai University, 200444 Shanghai, China
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, 200032 Shanghai, China
| | - Jin-Hong Lin
- Department of Chemistry, Innovative Drug Research Center, Shanghai University, 200444 Shanghai, China
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, 200032 Shanghai, China
| | - Ji-Chang Xiao
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, 200032 Shanghai, China
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2
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Nyagilo VO, Mallojjala SC, Hirschi JS. Transition State Analysis of Key Steps in Dual Photoredox-Cobalt-Catalyzed Elimination of Alkyl Bromides. ACS Catal 2024; 14:4683-4689. [PMID: 39211423 PMCID: PMC11361288 DOI: 10.1021/acscatal.3c06324] [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] [Indexed: 09/04/2024]
Abstract
A combination of inter- and intramolecular 13C kinetic isotope effects and density functional theory analysis is used to evaluate the key mechanistic events of sequentially operating catalytic cycles in the dual photoredox-cobalt-catalyzed elimination of alkyl bromides. The results point to a mechanism proceeding via irreversible halogen-atom transfer (XAT) from the alkyl halide, resulting in an alkyl radical, which undergoes hydrogen-atom transfer (HAT) to a Co(II) intermediate to deliver the product olefin. Alternative pathways involving nucleophilic substitution by a Co(I) species and by β-hydride elimination are discounted based on the poor agreement of experimental and predicted 13C KIEs. This mechanistic understanding is used to evaluate the origins of regioselectivity in the elimination step for an unsymmetrical alkyl halide catalyzed by electronically and sterically distinct cobaloxime catalysts. This study represents the experimental validation of the key features of the transition state structure of XAT by α-aminoalkyl radicals, an important class of atom transfer reactions that generate carbon-centered radicals from alkyl and aryl halides. Furthermore, it illustrates the power of 13C KIEs in probing complex mechanisms in metallaphotoredox catalysis.
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Affiliation(s)
- Victor O Nyagilo
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | | | - Jennifer S Hirschi
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
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3
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Colin-Molina A, Nematiaram T, Cheung AMH, Troisi A, Frisbie CD. The Conductance Isotope Effect in Oligophenylene Imine Molecular Wires Depends on the Number and Spacing of 13C-Labeled Phenylene Rings. ACS NANO 2024; 18:7444-7454. [PMID: 38411123 DOI: 10.1021/acsnano.3c11327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
We report a strong and structurally sensitive 13C intramolecular conductance isotope effect (CIE) for oligophenyleneimine (OPI) molecular wires connected to Au electrodes. Wires were built from Au surfaces beginning with the formation of 4-aminothiophenol self-assembled monolayers (SAMs) followed by subsequent condensation reactions with 13C-labeled terephthalaldehyde and phenylenediamine; in these monomers the phenylene rings were either completely 13C-labeled or the naturally abundant 12C isotopologues. Alternatively, perdeuterated versions of terephthalaldehyde and phenylenediamine were employed to make 2H(D)-labeled OPI wires. For 13C-isotopologues of short OPI wires (<4 nm) in length where the charge transport mechanism is tunneling, there was no measurable effect, i.e., 13C CIE ≈ 1, where CIE is defined as the ratio of labeled and unlabeled wire resistances, i.e., CIE = Rheavy/Rlight. However, for long OPI wires >4 nm, in which the transport mechanism is polaron hopping, a strong 13C CIE = 4-5 was observed. A much weaker inverse CIE < 1 was evident for the longest D-labeled wires. Importantly, the magnitude of the 13C CIE was sensitive to the number and spacing of 13C-labeled rings, i.e., the CIE was structurally sensitive. The structural sensitivity is intriguing because it may be employed to understand polaron hopping mechanisms and charge localization/delocalization in molecular wires. A preliminary theoretical analysis explored several possible explanations for the CIE, but so far a fully satisfactory explanation has not been identified. Nevertheless, the latest results unambiguously demonstrate structural sensitivity of the heavy atom CIE, offering directions for further utilization of this interesting effect.
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Affiliation(s)
- Abraham Colin-Molina
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Tahereh Nematiaram
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G11XL, United Kingdom
| | - Andy Man Hong Cheung
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Alessandro Troisi
- Department of Chemistry, University of Liverpool, Liverpool L697ZD, United Kingdom
| | - C Daniel Frisbie
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
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4
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Delaney CP, Lin E, Huang Q, Yu IF, Rao G, Tao L, Jed A, Fantasia SM, Püntener KA, Britt RD, Hartwig JF. Cross-coupling by a noncanonical mechanism involving the addition of aryl halide to Cu(II). Science 2023; 381:1079-1085. [PMID: 37676958 DOI: 10.1126/science.adi9226] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 08/08/2023] [Indexed: 09/09/2023]
Abstract
Copper complexes are widely used in the synthesis of fine chemicals and materials to catalyze couplings of heteroatom nucleophiles with aryl halides. We show that cross-couplings catalyzed by some of the most active catalysts occur by a mechanism not previously considered. Copper(II) [Cu(II)] complexes of oxalamide ligands catalyze Ullmann coupling to form the C-O bond in aryl ethers by concerted oxidative addition of an aryl halide to Cu(II) to form a high-valent species that is stabilized by radical character on the oxalamide ligand. This mechanism diverges from those involving Cu(I) and Cu(III) intermediates that have been posited for other Ullmann-type couplings. The stability of the Cu(II) state leads to high turnover numbers, >1000 for the coupling of phenoxide with aryl chloride electrophiles, as well as an ability to run the reactions in air.
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Affiliation(s)
- Connor P Delaney
- College of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Eva Lin
- College of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Qinan Huang
- College of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Isaac F Yu
- College of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Guodong Rao
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
| | - Lizhi Tao
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
| | - Ana Jed
- College of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Serena M Fantasia
- Pharmaceutical Division, Synthetic Molecules Technical Development, Process Chemistry and Catalysis, F. Hoffmann-La Roche, Ltd., Basel, CH-4070, Switzerland
| | - Kurt A Püntener
- Pharmaceutical Division, Synthetic Molecules Technical Development, Process Chemistry and Catalysis, F. Hoffmann-La Roche, Ltd., Basel, CH-4070, Switzerland
| | - R David Britt
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
- Miller Institute for Basic Research in Science, University of California, Berkeley, CA 94720, USA
| | - John F Hartwig
- College of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
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5
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Firsan S, Sivakumar V, Colacot TJ. Emerging Trends in Cross-Coupling: Twelve-Electron-Based L 1Pd(0) Catalysts, Their Mechanism of Action, and Selected Applications. Chem Rev 2022; 122:16983-17027. [PMID: 36190916 PMCID: PMC9756297 DOI: 10.1021/acs.chemrev.2c00204] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Indexed: 01/25/2023]
Abstract
Monoligated palladium(0) species, L1Pd(0), have emerged as the most active catalytic species in the cross-coupling cycle. Today, there are methods available to generate the highly active but unstable L1Pd(0) catalysts from stable precatalysts. While the size of the ligand plays an important role in the formation of L1Pd(0) during in situ catalysis, the latter can be precisely generated from the precatalyst by various technologies. Computational, kinetic, and experimental studies indicate that all three steps in the catalytic cycle─oxidative addition, transmetalation, and reductive elimination─contain monoligated Pd. The synthesis of precatalysts, their mode of activation, application studies in model systems, as well as in industry are discussed. Ligand parametrization and AI based data science can potentially help predict the facile formation of L1Pd(0) species.
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Affiliation(s)
- Sharbil
J. Firsan
- Science
and Lab Solutions−Chemistry, MilliporeSigma, 6000 North Teutonia Avenue, Milwaukee, Wisconsin53209, United States
| | - Vilvanathan Sivakumar
- Merck
Life Science Pvt Ltd, No-12, Bommasandra-Jigani Link Road, Industrial Area, Bangalore560100, India
| | - Thomas J. Colacot
- Science
and Lab Solutions−Chemistry, MilliporeSigma, 6000 North Teutonia Avenue, Milwaukee, Wisconsin53209, United States
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6
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Mallojjala SC, Nyagilo VO, Corio SA, Adili A, Dagar A, Loyer KA, Seidel D, Hirschi JS. Probing the Free Energy Landscape of Organophotoredox-Catalyzed Anti-Markovnikov Hydrofunctionalization of Alkenes. J Am Chem Soc 2022; 144:17692-17699. [PMID: 36112933 DOI: 10.1021/jacs.2c07807] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Experimental 13C kinetic isotope effects (KIEs) provide unprecedented mechanistic insight into three intermolecular anti-Markovnikov alkene hydrofunctionalization reactions─hydroesterification, hydroamination, and hydroetherification─enabled by organophotoredox catalysis. All three reactions are found to proceed via initial oxidation of the model alkenes to form a radical cation intermediate, followed by sequential nucleophilic attack and hydrogen-atom transfer to deliver the hydrofunctionalized product. A normal 13C KIE on the olefinic carbon that undergoes nucleophilic attack provides qualitative evidence for rate-limiting nucleophilic attack in all three reactions. Comparison to predicted 13C KIE values obtained from density functional theory (DFT) calculations for this step reveals that alkene oxidation has partial rate-limiting influence in hydroesterification and hydroamination, while the nucleophilic attack is solely rate-limiting in the hydroetherification reaction. The basic additive (2,6-lutidine) activates the nucleophile via deprotonation and is an integral part of the transition state for nucleophilic attack on the radical cation, providing an important design principle for the development of asymmetric versions of these reactions. A more electron-rich pyridine base (2,6-dimethoxypyridine) exhibits considerable rate enhancements in both inter- and intramolecular hydrofunctionalization reactions.
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Affiliation(s)
| | - Victor O. Nyagilo
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Stephanie A. Corio
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Alafate Adili
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Anuradha Dagar
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Kimberly A. Loyer
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Jennifer S. Hirschi
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
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7
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Chandra Mallojjala S, Sarkar R, Karugu RW, Manna MS, Ray S, Mukherjee S, Hirschi JS. Mechanism and Origin of Remote Stereocontrol in the Organocatalytic Enantioselective Formal C(sp 2)–H Alkylation Using Nitroalkanes as Alkylating Agents. J Am Chem Soc 2022; 144:17399-17406. [PMID: 36108139 DOI: 10.1021/jacs.2c02941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Experimental 13C kinetic isotope effects (KIEs) and density functional theory (DFT) calculations are used to evaluate the mechanism and origin of enantioselectivity in the formal C(sp2)-H alkylative desymmetrization of cyclopentene-1,3-diones using nitroalkanes as the alkylating agent. An unusual combination of an inverse (∼0.980) and a normal (∼1.033) KIE is observed on the bond-forming carbon atoms of the cyclopentene-1,3-dione and nitroalkane, respectively. These data provide strong support for a mechanism involving reversible carbon-carbon bond formation followed by rate- and enantioselectivity-determining nitro group elimination. The theoretical free-energy profile and the predicted KIEs indicate that this elimination event occurs via an E1cB pathway. The origin of remote stereocontrol is evaluated by distortion-interaction and SAPT0 analyses of the E1cB transition states leading to both enantiomers.
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Affiliation(s)
| | - Rahul Sarkar
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Rachael W. Karugu
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Madhu Sudan Manna
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Sayan Ray
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Santanu Mukherjee
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Jennifer S. Hirschi
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
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8
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Horbaczewskyj CS, Fairlamb IJS. Pd-Catalyzed Cross-Couplings: On the Importance of the Catalyst Quantity Descriptors, mol % and ppm. Org Process Res Dev 2022; 26:2240-2269. [PMID: 36032362 PMCID: PMC9396667 DOI: 10.1021/acs.oprd.2c00051] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Indexed: 12/26/2022]
Abstract
![]()
This Review examines parts per million (ppm) palladium
concentrations
in catalytic cross-coupling reactions and their relationship with
mole percentage (mol %). Most studies in catalytic cross-coupling
chemistry have historically focused on the concentration ratio between
(pre)catalyst and the limiting reagent (substrate), expressed as mol
%. Several recent papers have outlined the use of “ppm level”
palladium as an alternative means of describing catalytic cross-coupling
reaction systems. This led us to delve deeper into the literature
to assess whether “ppm level” palladium is a practically
useful descriptor of catalyst quantities in palladium-catalyzed cross-coupling
reactions. Indeed, we conjectured that many reactions could, unknowingly,
have employed low “ppm levels” of palladium (pre)catalyst,
and generally, what would the spread of ppm palladium look like across
a selection of studies reported across the vast array of the cross-coupling
chemistry literature. In a few selected examples, we have examined
other metal catalyst systems for comparison with palladium.
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Affiliation(s)
| | - Ian J. S. Fairlamb
- University of York, Heslington, York, North Yorkshire, YO10 5DD, United Kingdom
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9
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Gribanov PS, Philippova AN, Topchiy MA, Minaeva LI, Asachenko AF, Osipov SN. General Method of Synthesis of 5-(Het)arylamino-1,2,3-triazoles via Buchwald-Hartwig Reaction of 5-Amino- or 5-Halo-1,2,3-triazoles. Molecules 2022; 27:1999. [PMID: 35335361 PMCID: PMC8949195 DOI: 10.3390/molecules27061999] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 02/01/2023] Open
Abstract
An efficient access to the novel 5-(het)arylamino-1,2,3-triazole derivatives has been developed. The method is based on Buchwald-Hartwig cross-coupling reaction of 5-Amino or 5-Halo-1,2,3-triazoles with (het)aryl halides and amines, respectively. As result, it was found that palladium complex [(THP-Dipp)Pd(cinn)Cl] bearing expanded-ring N-heterocyclic carbene ligand is the most active catalyst for the process to afford the target molecules in high yields.
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Affiliation(s)
- Pavel S. Gribanov
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova Str., 119991 Moscow, Russia; (A.N.P.); (S.N.O.)
| | - Anna N. Philippova
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova Str., 119991 Moscow, Russia; (A.N.P.); (S.N.O.)
| | - Maxim A. Topchiy
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninskiy Prospect 29, 119991 Moscow, Russia; (M.A.T.); (L.I.M.); (A.F.A.)
| | - Lidiya I. Minaeva
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninskiy Prospect 29, 119991 Moscow, Russia; (M.A.T.); (L.I.M.); (A.F.A.)
| | - Andrey F. Asachenko
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninskiy Prospect 29, 119991 Moscow, Russia; (M.A.T.); (L.I.M.); (A.F.A.)
| | - Sergey N. Osipov
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova Str., 119991 Moscow, Russia; (A.N.P.); (S.N.O.)
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10
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Dale HJA, Leach AG, Lloyd-Jones GC. Heavy-Atom Kinetic Isotope Effects: Primary Interest or Zero Point? J Am Chem Soc 2021; 143:21079-21099. [PMID: 34870970 DOI: 10.1021/jacs.1c07351] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chemists have many options for elucidating reaction mechanisms. Global kinetic analysis and classic transition-state probes (e.g., LFERs, Eyring) inevitably form the cornerstone of any strategy, yet their application to increasingly sophisticated synthetic methodologies often leads to a wide range of indistinguishable mechanistic proposals. Computational chemistry provides powerful tools for narrowing the field in such cases, yet wholly simulated mechanisms must be interpreted with great caution. Heavy-atom kinetic isotope effects (KIEs) offer an exquisite but underutilized method for reconciling the two approaches, anchoring the theoretician in the world of calculable observables and providing the experimentalist with atomistic insights. This Perspective provides a personal outlook on this synergy. It surveys the computation of heavy-atom KIEs and their measurement by NMR spectroscopy, discusses recent case studies, highlights the intellectual reward that lies in alignment of experiment and theory, and reflects on the changes required in chemical education in the area.
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Affiliation(s)
- Harvey J A Dale
- EaStChem, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Andrew G Leach
- School of Health Sciences, The University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PT, U.K
| | - Guy C Lloyd-Jones
- EaStChem, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K
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