Skip to content

Research at St Andrews

Difluorocarbene generation from TMSCF3: kinetics and mechanism of NaI-mediated and Si-induced anionic chain reactions

Research output: Contribution to journalArticlepeer-review

DOI

Open Access Status

  • Embargoed (until 27/07/21)

Author(s)

Andrés García-Domínguez, Thomas H. West, Johann J. Primozic, Katie M. Grant, Craig P. Johnston, Grant G. Cumming, Andrew G. Leach, Guy C. Lloyd-Jones

School/Research organisations

Abstract

The mechanism of CF2 transfer from TMSCF3 (1), mediated by TBAT (2–12 mol %) or by NaI (5–20 mol %), has been investigated by in situ/stopped-flow 19F NMR spectroscopic analysis of the kinetics of alkene difluorocyclopropanation and competing TFE/c-C3F6/homologous perfluoroanion generation, 13C/2H KIEs, LFERs, CF2 transfer efficiency and selectivity, the effect of inhibitors, and density functional theory (DFT) calculations. The reactions evolve with profoundly different kinetics, undergoing autoinhibition (TBAT) or quasi-stochastic autoacceleration (NaI) and cogenerating perfluoroalkene side products. An overarching mechanism involving direct and indirect fluoride transfer from a CF3 anionoid to TMSCF3 (1) has been elucidated. It allows rationalization of why the NaI-mediated process is more effective for less-reactive alkenes and alkynes, why a large excess of TMSCF3 (1) is required in all cases, and why slow-addition protocols can be of benefit. Issues relating to exothermicity, toxicity, and scale-up are also noted.
Close

Details

Original languageEnglish
Pages (from-to)14649-14663
JournalJournal of the American Chemical Society
Volume142
Issue number34
Early online date27 Jul 2020
DOIs
Publication statusPublished - 26 Aug 2020

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. Safe, sustainable and scalable

    Johnston, C. P., 24 Apr 2019, In: Nature Chemistry. 11, 5, p. 400-401

    Research output: Contribution to journalBook/Film/Article review

  2. Anion-initiated trifluoromethylation by TMSCF3: deconvolution of the siliconate–carbanion dichotomy by stopped-flow NMR/IR

    Johnston, C. P., West, T. H., Dooley, R. E., Reid, M., Jones, A. B., King, E. J., Leach, A. G. & Lloyd-Jones, G. C., 5 Sep 2018, In: Journal of the American Chemical Society. 140, 35, p. 11112-11124 13 p.

    Research output: Contribution to journalArticlepeer-review

  3. Metallaphotoredox-catalysed sp3sp3 cross-coupling of carboxylic acids with alkyl halides

    Johnston, C. P., Smith, R. T., Allmendinger, S. & MacMillan, D. W. C., 18 Aug 2016, In: Nature. 536, 7616, p. 322-325 4 p.

    Research output: Contribution to journalArticlepeer-review

  4. Cation-controlled enantioselective and diastereoselective synthesis of indolines: an autoinductive phase-transfer initiated 5-endo-trig process

    Sharma, K., Wolstenhulme, J. R., Painter, P. P., Yeo, D., Grande-Carmona, F., Johnston, C. P., Tantillo, D. J. & Smith, M. D., 21 Oct 2015, In: Journal of the American Chemical Society. 137, 41, p. 13414-13424

    Research output: Contribution to journalArticlepeer-review

  5. Catalytic enantioselective synthesis of indanes by a cation-directed 5-endo-trig cyclization

    Johnston, C. P., Kothari, A., Sergeieva, T., Okovytyy, S. I., Jackson, K. E., Paton, R. S. & Smith, M. D., Feb 2015, In: Nature Chemistry. 7, 2, p. 171-177 7 p.

    Research output: Contribution to journalArticlepeer-review

Related by journal

  1. Journal of the American Chemical Society (Journal)

    David Trevor Richens (Editor)

    2005 → …

    Activity: Publication peer-review and editorial work typesEditor of research journal

Related by journal

  1. A deep blue B,N-doped heptacene emitter that shows both thermally activated delayed fluorescence and delayed fluorescence by triplet-triplet annihilation

    Madayanad Suresh, S., Duda, E., Hall, D., Yao, Z., Bagnich, S., Slawin, A. M. Z., Bässler, H., Beljonne, D., Buck, M., Olivier, Y., Köhler, A. & Zysman-Colman, E., 8 Apr 2020, In: Journal of the American Chemical Society. 142, 14, p. 6588–6599

    Research output: Contribution to journalArticlepeer-review

  2. Encoding multiple reactivity modes within a single synthetic replicator

    Robertson, C. C., Kosikova, T. & Philp, D., 15 May 2020, In: Journal of the American Chemical Society. Just Accepted

    Research output: Contribution to journalArticlepeer-review

  3. Facile, room-temperature 17O enrichment of zeolite frameworks revealed by solid-state NMR spectroscopy

    Pugh, S. M., Wright, P. A., Law, D., Thompson, N. & Ashbrook, S. E., 15 Jan 2020, In: Journal of the American Chemical Society. 142, 2, p. 900-906 7 p.

    Research output: Contribution to journalArticlepeer-review

  4. Hydrogenative depolymerization of nylons

    Kumar, A., von Wolff, N., Rauch, M., Zou, Y-Q., Shmul, G., Ben-David, Y., Leitus, G., Avram, L. & Milstein, D., 19 Aug 2020, In: Journal of the American Chemical Society. 142, 33, p. 14267-14275

    Research output: Contribution to journalArticlepeer-review

ID: 270005946

Top