Rearrangement and double fluorination in the deiodinative fluorination of neopentyl iodide with xenon difluoride

Patrick, Timothy B.; Zhang, Likang; Li, Quinhua

doi:10.1016/s0022-1139(99)00234-1

Cited by 15 publications

(6 citation statements)

References 16 publications

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“…All of the calculated 1 J FC constants were benchmarked against the experimental values, which were obtained from the literature − (the values can be found in the Supporting Information). To best reproduce the experimental data, we included the solvent implicitly as a polarizable continuous cavity, according to the IEFPCM model. − The solvent was chosen so as to reflect the conditions in which the experimental NMR spectra were recorded.…”

Section: Computational Detailsmentioning

confidence: 99%

On the Unexpected Accuracy of the M06L Functional in the Calculation of ¹J_FC Spin–Spin Coupling Constants

Giovanetti

Bitencourt

Cormanich

et al. 2021

J. Chem. Theory Comput.

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One-bond spin−spin coupling constants (SSCCs) between F and C are computed with density functional theory (DFT). Surprisingly, M06L stands out for its striking accuracy, outperforming any other investigated functional, including PBE0, otherwise considered one of the most reliable for couplings involving F. Although the computation of nuclear magnetic resonance (NMR) parameters involving F is known to be a challenging task, even with a rather small basis set as pcJ-1, M06L provides results with a MAD = 11.7 Hz, whereas the average deviation gets as much as 5 times larger for PBE0 (MAD = 60.0 Hz). In the context of SSCCs on the order of 300 Hz, this is particularly remarkable. We find that the accuracy of M06L/pcJ-1 in predicting 1 J FC constants does not stem from a well-suited exchange or correlation part of the functional. Instead, it is believed to arise from a fortuitous cancellation of errors, as revealed by investigating the convergence of the basis set. Our findings also indicate that 1 J FC constants are highly dependent on the amount of exact exchange included in the expression of the functional, with large fractions being critically important to achieving satisfactory results. Studying the effects of the geometry on 1 J FC , we find that optimizing the geometry at the level of theory used to calculate SSCCs generally improves the quality of the results, although the combination of a M06-2X/aug-cc-pVTZ geometry with M06L/ pcJ-1 1 J FC constants best reproduces the experimental data for organofluorine compounds (with the exception of fluoroalkenes).

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Section: Computational Detailsmentioning

confidence: 99%

On the Unexpected Accuracy of the M06L Functional in the Calculation of ¹J_FC Spin–Spin Coupling Constants

Giovanetti

Bitencourt

Cormanich

et al. 2021

J. Chem. Theory Comput.

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“…Fluorine may be introduced in many forms, though chemical reaction conditions are often quite severe and reagents include HF [54], various metal halides [55], SeF 4 [56], WF 6 [57], XeF 2 [58], SbF 5 [59], F 2 [60,61], Sethyltrifluorothioacetate [62] and trifluoroacetic anhydride [63]. Thus, it may be preferable to incorporate a moiety into synthetic planning, which already includes the desired fluorine atoms, e.g., trifluoromethyl.…”

Section: F As An In Vivo Nmr Probementioning

confidence: 99%

“…ii) Ligands designed to trap/bind specific entities, such as ions, specifically, but reversibly, e.g., H + (pH) (Section 3.2), metal ions (Ca 2+ , Mg 2+ ) (Section 3.3); iii) perfluorocarbons, which exhibit exceptional gas solubility and reveal oxygen tension based on modification of relaxation parameters (Section 3.4.1). [56] , PhPF 4 [356], HF [54], CH 3 CH 2 FCH 3 Difluoroalkane RCH 2 CF 2 R' or RCHF(CH 2 ) n CHFR' ClF [357] , XeF 2 [58] , KF [358] , CF 2 Br 2 [359] , …”

Section: Active Agentsmentioning

confidence: 99%

19F: A Versatile Reporter for Non-Invasive Physiology and Pharmacology Using Magnetic Resonance

Jian¹,

Kodibagkar²,

Cui³

et al. 2005

CMC

229

185

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The fluorine atom provides an exciting tool for diverse spectroscopic and imaging applications using Magnetic Resonance. The organic chemistry of fluorine is widely established and it can provide a stable moiety for interrogating many aspects of physiology and pharmacology in vivo. Strong NMR signal, minimal background signal and exquisite sensitivity to changes in the microenvironment have been exploited to design and apply diverse reporter molecules. Classes of agents are presented to investigate gene activity, pH, metal ion concentrations (e.g., Ca(2+), Mg(2+), Na(+)), oxygen tension, hypoxia, vascular flow and vascular volume. In addition to interrogating speciality reporter molecules, (19)F NMR may be used to trace the fate of fluorinated drugs, such as chemotherapeutics (e.g., 5-fluorouracil, gemcitabine), anesthetics (e.g., isoflurane, methoxyflurane) and neuroleptics. NMR can provide useful information through multiple parameters, including chemical shift, scalar coupling, chemical exchange and relaxation processes (R1 and R2). Indeed, the large chemical shift range (approximately 300 ppm) can allow multiple agents to be examined, simultaneously, using NMR spectroscopy or chemical shift selective imaging.

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“…However, the fluorination of tertiary alkyl halides remains a formidable challenge . The halogen‐exchange fluorination with Cu 2 O‐HF‐THF or AgF, and the oxidative deiodinative fluorination with F 2 , XeF 2 ,– p ‐iodotoluene difluorides,, or iodonium fluoride, have been reported for tertiary alkyl halides. These reactions proceed via carbocation intermediates (Figure ), and thus suffer from the competing solvolysis, elimination, or rearrangement reactions (see below).…”

Section: Figurementioning

confidence: 99%

Selective Radical Fluorination of Tertiary Alkyl Halides at Room Temperature

Chen

Liu

et al. 2017

Angewandte Chemie

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Direct fluorination of tertiary alkyl bromides and iodides with Selectfluor is described. The halogen‐exchange fluorination proceeds efficiently in acetonitrile at room temperature under metal‐free conditions and exhibits a wide range of functional group compatibility. Furthermore, the reactions are highly selective in that alkyl chlorides and primary and secondary alkyl bromides remain intact. A radical mechanism is proposed for this selective fluorination.

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Rearrangement and double fluorination in the deiodinative fluorination of neopentyl iodide with xenon difluoride

Cited by 15 publications

References 16 publications

On the Unexpected Accuracy of the M06L Functional in the Calculation of ¹J_FC Spin–Spin Coupling Constants

On the Unexpected Accuracy of the M06L Functional in the Calculation of ¹J_FC Spin–Spin Coupling Constants

19F: A Versatile Reporter for Non-Invasive Physiology and Pharmacology Using Magnetic Resonance

Selective Radical Fluorination of Tertiary Alkyl Halides at Room Temperature

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Rearrangement and double fluorination in the deiodinative fluorination of neopentyl iodide with xenon difluoride

Cited by 15 publications

References 16 publications

On the Unexpected Accuracy of the M06L Functional in the Calculation of 1JFC Spin–Spin Coupling Constants

On the Unexpected Accuracy of the M06L Functional in the Calculation of 1JFC Spin–Spin Coupling Constants

19F: A Versatile Reporter for Non-Invasive Physiology and Pharmacology Using Magnetic Resonance

Selective Radical Fluorination of Tertiary Alkyl Halides at Room Temperature

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On the Unexpected Accuracy of the M06L Functional in the Calculation of ¹J_FC Spin–Spin Coupling Constants

On the Unexpected Accuracy of the M06L Functional in the Calculation of ¹J_FC Spin–Spin Coupling Constants