Synthesis and characterization of a novel N–F reagent derived from the ethano-Tröger's base: <sup>1</sup>J<sub>FN</sub> coupling constants as a signature for the N–F bond

Pereira, Raul; Wolstenhulme, Stephen; Sandford, Graham; Claridge, Timothy D. W.; Gouverneur, Véronique; Cvengroš, Ján

doi:10.1039/c5cc08375c

Cited by 19 publications

(21 citation statements)

References 54 publications

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“…In Figure , we show the cationic compounds computationally investigated in this work. We have used the same numbering of the original paper, Pereira et al, for an easier reference. The experiments were run in acetonitrile for the corresponding triflate salts, except for 5 that was a bis (tetrafluoroborate) salt.…”

Section: Resultsmentioning

confidence: 96%

“…Structural formula of the cationic compounds investigated in this work and experimentally studied in Pereira et al For an easier reference to the experimental paper, we have used the same numbering scheme as in Pereira et al…”

Section: Resultsmentioning

confidence: 99%

“…Particularly relevant to organofluorine chemistry is the choice of the fluorine source. Recently, some new fluorinating reagents, together with other well‐known compounds, have been presented and characterized by NMR spectroscopy . Direct coupling constant, 1 J ( 15 N─ 19 F), between fluorine and nitrogen have been measured in acetonitrile, and the correlation between the magnitude of the coupling and the structural properties and reactivity of the fluorinating reagent has been discussed by the Authors.…”

Section: Introductionmentioning

confidence: 99%

“…Direct coupling constant, 1 J ( 15 N─ 19 F), between fluorine and nitrogen have been measured in acetonitrile, and the correlation between the magnitude of the coupling and the structural properties and reactivity of the fluorinating reagent has been discussed by the Authors. However, Pereira et al could only determine the magnitude of the one‐bond 1 J ( 15 N─ 19 F) spin–spin coupling constants (SSCCs) whereas the sign was assumed to be negative, based on the well‐known Dirac vector model for one‐bond couplings …”

Section: Introductionmentioning

confidence: 99%

“…In this paper, we apply DFT computational protocols to predict the one‐bond 1 J ( 15 N─ 19 F) coupling constant in the fluorinating reagents experimentally discussed in the previous study and provide a rational for the observed magnitude and sign obtained from the calculations. Analysis of the orbital contributions to the SSCCs will help to rationalize the calculated positive sign of the J SSCC, contrary to the expectations of a negative one‐bond 1 J ( 15 N─ 19 F) couplings.…”

Section: Introductionmentioning

confidence: 99%

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One‐bond ¹J(¹⁵N─¹⁹F) spin–spin coupling constants of cationic fluorinating reagents: Insights from DFT calculations

Saielli

2019

Magnetic Reson in Chemistry

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We have investigated, by means of density functional theory protocols, the one-bond 1 J( 15 N─ 19 F) spin-spin coupling constants in a series of fluorinating reagents, containing the N─F bond, recently studied experimentally. The results of the calculations show a very good linear relationship with the experimental values, even though only the M06-2X(PCM)/pcJ-2//B3LYP/6-311G(d,p) level affords a very low mean absolute error. The calculations allow to analyze the various molecular orbitals contributions to the J coupling and to rationalize the observed positive sign, corresponding to a negative sign of the reduced spin-pin coupling constant K(N─F). Moreover, of the four Ramsey contributions, only the diamagnetic spin orbit is negligible, whereas the paramagnetic spin orbit and spin dipole terms decrease the magnitude of the Fermi contact (FC) term by an amount that goes from a minimum of 35% up to more than 60% of the FC term itself. Several effects have been investigated, namely, the contribution of the long-range solvent reaction field, relativistic corrections, and conformational and vibrational effects.

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Section: Resultsmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

One‐bond ¹J(¹⁵N─¹⁹F) spin–spin coupling constants of cationic fluorinating reagents: Insights from DFT calculations

Saielli

2019

Magnetic Reson in Chemistry

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Mild Stereoselective Intermolecular Acetoxylation and Azidation of α‐C−H Bonds in Tröger's Bases

et al. 2016

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Introduction of oxygen and nitrogen into organic molecules is one of the fundamental strategies for their functionalization. Traditional approaches rely on the formation of an activated intermediate, which is then modified in a subsequent step. Here we report a simple direct oxidative α‐acetoxylation and azidation of α‐C−H bonds in Tröger's base analogues promoted by N‐bromosuccinimide (NBS) and palladium(II)acetate [Pd(OAc)2] under mild conditions. This approach is pivotal on NBS oxidizing the carbon atoms next to the nitrogen atoms in the presence of Pd(OAc)2 followed by a reaction with oxygen‐ or nitrogen‐centred nucleophiles such as KOAc or NaN3 to yield either the mono‐ and bisacetoxylated or azidated Tröger's base derivatives in a stereo‐ and chemoselective manner. The obtained products can be efficiently modified to access synthetically meaningful structures.magnified image

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Selectfluor^TM on a PolyHIPE Material as Regenerative and Reusable Polymer‐Supported Electrophilic Fluorinating Agent

et al. 2016

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Thef irst recyclable polymer-supported electrophilic fluorinating agent was preparedb yr eaction of molecular fluorine with the triethylenediamine motif that is graftedo ntoapoly(4-vinylbenzyl chloride-co-divinylbenzene) polyHIPE material. Ther esulting polymeric Selectfluor TM -type reagent demonstrated high efficiency in the fluorination of naphthol in the course of repeated sequences of fluorination and regeneration. It also reacted with the enol form and the sodium enolate of 1,3-dicarbonyl compounds.Thes ynthesiso fs electively fluorinated new chemical entitiesi sa ni mportant challenge in organic chemistry that receives an ever-growing attention due to the wide potential applications in the life science fields and materialss cience.I ndeed, the chemical positioning of af luorine atom, which possesses as trong electron-withdrawing ability andarelatively small size, often leads to stunning changes in the physical, chemical and biological properties of fluorinated compounds when compared with their non-fluorinated analogues. [1] From as ynthetic point of view,t he direct and selectivee lectrophilic fluorination of organic compounds was madep ossible thanks to ac ollection of various fluorinating agents. [2][3][4] In the early stages, sources of positive fluorinew ered esigned featuring the O-F moiety (fluoroxyperfluoroalkanes R f OF,p erfluoroacyl hypofluorites R f COOF,a nd sulfonyl hypofluorites R f SO 2 OF) but theire xplosiven ature caused their rapid phase-out. [3] Thereafter, N-F reagents emerged as safer ands helf-stable reagents for electrophilic fluorinations. [4] Aw ide range of fluorinating powerst ogether with commercial availability secured awidespread use of this class of reagents.Representative reagents include NFSI (N-fluorobenzenesulfonimide), N-fluoropyridinium salts and Selectfluor TM {1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2,2,2]octane bis(tetrafluoroborate) or F-TEDA-BF 4 ;T EDA = triethylenediamine}. These reagents have been continuously employed in aw ide variety of fluorination reactions;h owever, they suffer from poora tom-economy because of theirh ighm olecular weightf or the transfer of 19 Fand no effort was made to recover and regenerate either the benzenesulfonimide,t he pyridine moietyo rt he TEDAr esidue of the corresponding reagents.I nap revious work on enantioselective electrophilic fluorination by means of quinine-based [N-F] + + reagents conducted in ionic liquids,t he Cinchona alkaloid as wella st he solvent were recycled. [5] With av iewt oe nsuring minimization of waste generation toward ag reenerc hemistry,w ee nvisaged the preparation, applications,a nd the regeneration of de novo polymeric architectures as support for electrophilic fluorinating agents.I nt he context of green chemistry,p olymer-supported reagents offer attractive and practical approaches for the clean and efficient synthesiso fo rganic compounds. [6] Polymeric electrophilic fluorinating agents are extremely rare.I n1 986,

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Synthesis and characterization of a novel N–F reagent derived from the ethano-Tröger's base: ¹J_FN coupling constants as a signature for the N–F bond

Cited by 19 publications

References 54 publications

One‐bond ¹J(¹⁵N─¹⁹F) spin–spin coupling constants of cationic fluorinating reagents: Insights from DFT calculations

One‐bond ¹J(¹⁵N─¹⁹F) spin–spin coupling constants of cationic fluorinating reagents: Insights from DFT calculations

Mild Stereoselective Intermolecular Acetoxylation and Azidation of α‐C−H Bonds in Tröger's Bases

Selectfluor^TM on a PolyHIPE Material as Regenerative and Reusable Polymer‐Supported Electrophilic Fluorinating Agent

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Synthesis and characterization of a novel N–F reagent derived from the ethano-Tröger's base: 1JFN coupling constants as a signature for the N–F bond

Cited by 19 publications

References 54 publications

One‐bond 1J(15N─19F) spin–spin coupling constants of cationic fluorinating reagents: Insights from DFT calculations

One‐bond 1J(15N─19F) spin–spin coupling constants of cationic fluorinating reagents: Insights from DFT calculations

Mild Stereoselective Intermolecular Acetoxylation and Azidation of α‐C−H Bonds in Tröger's Bases

SelectfluorTM on a PolyHIPE Material as Regenerative and Reusable Polymer‐Supported Electrophilic Fluorinating Agent

Contact Info

Product

Resources

About

Synthesis and characterization of a novel N–F reagent derived from the ethano-Tröger's base: ¹J_FN coupling constants as a signature for the N–F bond

One‐bond ¹J(¹⁵N─¹⁹F) spin–spin coupling constants of cationic fluorinating reagents: Insights from DFT calculations

One‐bond ¹J(¹⁵N─¹⁹F) spin–spin coupling constants of cationic fluorinating reagents: Insights from DFT calculations

Selectfluor^TM on a PolyHIPE Material as Regenerative and Reusable Polymer‐Supported Electrophilic Fluorinating Agent