Stannylene hydrides as key intermediates in redox neutral Sn(II)/Sn(II) catalysis: Hydrodefluorination as a case study
- 1Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Baden-Württemberg, Germany, 69120
Abstract
Low-valent tin hydrides display hydride donor properties that differ markedly from those of conventional organotin(IV) hydrides, yet their catalytic applications have remained largely confined to reactions of polar multiple bonds. Herein, we exploit this distinct reactivity for catalytic C–F bond activation and investigate the mechanism underlying the hydrodefluorination of polyfluoroarenes. An isolable diketiminate-supported Sn(II) fluoride efficiently catalyses the reaction using phenylsilane as terminal hydride source. Stoichiometric and spectroscopic studies establish rapid fluoride–hydride exchange between the stannylene fluoride and phenylsilane, generating a catalytically competent stannylene hydride that directly reacts with polyfluoroarenes to form the hydrodefluorination product and regenerate the Sn(II) fluoride. Density functional theory calculations of its hydricity reveals a substantially greater thermodynamic propensity for hydride transfer than n Bu 3 SnH and further distinguish between two plausible pathways for C–F activation: direct hydride transfer proceeds through concerted nucleophilic aromatic substitution ( c S N Ar) and is favoured over competing oxidative addition to Sn(II). The resulting catalytic cycle therefore operates entirely at Sn(II), combining fluoride–hydride exchange with polar C–F substitution rather than Sn(II)/Sn(IV) redox cycling. These findings establish low-valent tin hydrides as competent intermediates for catalytic C–F bond activation and illustrate how their pronounced hydride donor ability can extend the mechanistic toolbox of stannylene catalysis.
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BibTeX
@misc{ballmaier2026stannylene,
title = {{Stannylene hydrides as key intermediates in redox neutral Sn(II)/Sn(II) catalysis: Hydrodefluorination as a case study}},
author = {Iris Ballmaier and Destiny L. T. Brumm and Tobias Morack},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15008300/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008300/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Stannylene hydrides as key intermediates in redox neutral Sn(II)/Sn(II) catalysis: Hydrodefluorination as a case study
AU - Iris Ballmaier
AU - Destiny L. T. Brumm
AU - Tobias Morack
PY - 2026
DA - 2026/09/04
PB - ChemRxiv
DO - 10.26434/chemrxiv.15008300/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008300/v1
AB - Low-valent tin hydrides display hydride donor properties that differ markedly from those of conventional organotin(IV) hydrides, yet their catalytic applications have remained largely confined to reactions of polar multiple bonds. Herein, we exploit this distinct reactivity for catalytic C–F bond activation and investigate the mechanism underlying the hydrodefluorination of polyfluoroarenes. An isolable diketiminate-supported Sn(II) fluoride efficiently catalyses the reaction using phenylsilane as terminal hydride source. Stoichiometric and spectroscopic studies establish rapid fluoride–hydride exchange between the stannylene fluoride and phenylsilane, generating a catalytically competent stannylene hydride that directly reacts with polyfluoroarenes to form the hydrodefluorination product and regenerate the Sn(II) fluoride. Density functional theory calculations of its hydricity reveals a substantially greater thermodynamic propensity for hydride transfer than n Bu 3 SnH and further distinguish between two plausible pathways for C–F activation: direct hydride transfer proceeds through concerted nucleophilic aromatic substitution ( c S N Ar) and is favoured over competing oxidative addition to Sn(II). The resulting catalytic cycle therefore operates entirely at Sn(II), combining fluoride–hydride exchange with polar C–F substitution rather than Sn(II)/Sn(IV) redox cycling. These findings establish low-valent tin hydrides as competent intermediates for catalytic C–F bond activation and illustrate how their pronounced hydride donor ability can extend the mechanistic toolbox of stannylene catalysis.
ER -