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Dumon AS, Rzepa HS, Alamillo-Ferrer C, Bures J, Procter R, Sheppard TD, Whiting A. A computational tool to accurately and quickly predict 19F NMR chemical shifts of molecules with fluorine-carbon and fluorine-boron bonds. Phys Chem Chem Phys 2022; 24:20409-20425. [PMID: 35983846 DOI: 10.1039/d2cp02317b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the evaluation of density-functional-theory (DFT) based procedures for predicting 19F NMR chemical shifts at modest computational cost for a range of molecules with fluorine bonds, to be used as a tool for assisting the characterisation of reaction intermediates and products and as an aid to identifying mechanistic pathways. The results for a balanced learning set of molecules were then checked using two further testing sets, resulting in the recommendation of the ωB97XD/aug-cc-pvdz DFT method and basis set as having the best combination of accuracy and computational time, with a RMS error of 3.57 ppm. Cationic molecules calculated without counter-anion showed normal errors, whilst anionic molecules showed somewhat larger errors. The method was applied to the prediction of the conformationally averaged 19F chemical shifts of 2,2,3,3,4,4,5,5-octafluoropentan-1-ol, in which gauche stereoelectronic effects involving fluorine dominate and to determining the position of coordination equilibria of fluorinated boranes as an aid to verifying the relative energies of intermediate species involved in catalytic amidation reactions involving boron catalysts.
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Affiliation(s)
- Alexandre S Dumon
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, Wood Lane, London W12 OBZ, UK.
| | - Henry S Rzepa
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, Wood Lane, London W12 OBZ, UK.
| | | | - Jordi Bures
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, UK
| | - Richard Procter
- Department of Chemistry, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - Tom D Sheppard
- Department of Chemistry, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - Andrew Whiting
- Centre for Sustainable Chemical Processes, Department of Chemistry, Science Laboratories, Durham University, South Road, Durham, DH1 3LE, UK
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Curtis ER, Hannigan MD, Vitek AK, Zimmerman PM. Quantum Chemical Investigation of Dimerization in the Schlenk Equilibrium of Thiophene Grignard Reagents. J Phys Chem A 2020; 124:1480-1488. [DOI: 10.1021/acs.jpca.9b09985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ethan R. Curtis
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, Michigan 48109, United States
| | - Matthew D. Hannigan
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, Michigan 48109, United States
| | - Andrew K. Vitek
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, Michigan 48109, United States
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, Michigan 48109, United States
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Budinská A, Václavík J, Matoušek V, Beier P. Nucleophilic Tetrafluoroethylation Employing in Situ Formed Organomagnesium Reagents. Org Lett 2016; 18:5844-5847. [PMID: 27797526 DOI: 10.1021/acs.orglett.6b02890] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tetrafluoroalkyl bromides are metalated with equimolar iPrMgCl·LiCl (Turbo Grignard) to form organomagnesium compounds which are stable at low temperatures and react with various electrophiles (aldehydes, ketones, CO2, cyclic sulfate and sulfamidate, N-sulfonylimines, nitrone, chlorophosphate, nonaflyl azide) to afford novel functionalized tetrafluoroethylene-containing products. Ease of operation, excellent selectivity, high nucleophilicity, and enhanced stability of the reactive species together with a broad substrate scope comprise a highly attractive nucleophilic tetrafluoroethylation protocol affording unique synthetic building blocks.
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Affiliation(s)
- Alena Budinská
- The Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences , Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic
| | - Jiří Václavík
- The Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences , Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic.,Laboratory of Molecular Structure Characterization, Institute of Microbiology, Academy of Sciences of the Czech Republic , Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Václav Matoušek
- CF Plus Chemicals s.r.o., Kamenice 771/34, 625 00 Brno, Czech Republic
| | - Petr Beier
- The Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences , Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic
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