Palladium-catalyzed electrophilic C–H fluorination of arenes using oxazoline as a removable directing group

Gutiérrez, David; Lee, Wan-Chen Cindy; Shen, Yuning; Li, Jie Jack

doi:10.1016/j.tetlet.2016.10.079

Cited by 28 publications

(20 citation statements)

References 18 publications

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“…[42], [43], [44], [45], [46], [47] [48] These include a diverse range of N-heterocycles and amides, motifs commonly encountered in medicinal chemistry. [49] This suggests that native motifs might be used as handles to direct late stage C-H fluorination for the synthesis of pharmaceutical drugs.…”

Section: ((Author Portrait))mentioning

confidence: 99%

The Fluorination of C−H Bonds: Developments and Perspectives

et al. 2019

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This Review summarizes the advances in fluorination via C(sp 2)-H and C(sp 3)-H activation. Transition metal catalyzed approaches championed by palladium have allowed the installation of a fluorine substituent at C(sp 2) and C(sp 3) sites exploiting the reactivity of high oxidation transition metal fluoride complexes combined with the use of directing group (some transient) to control regio-and stereoselectivity. The large majority of known methods employ electrophilic fluorination reagents, but methods combining a nucleophilic fluoride source with an oxidant have appeared. A number of ligands have proven to be effective for C(sp 3)-H fluorination directed by weakly coordinating auxiliaries, thereby enabling control over reactivity and selectivity. Methods relying on the formation of radical intermediates are complementary to transition metal catalyzed processes as they allow for undirected C(sp 3)-H fluorination. To date, radical C-H fluorinations mainly employ electrophilic N-F fluorination reagents but a unique bio-inspired Mn(III)-catalyzed oxidative C-H fluorination has been developed. Overall, the field of late stage nucleophilic C-H fluorination has progressed much more slowly, a state of play explaining why C-H 18 F-fluorination is still in its infancy. C-F reductive elimination C(sp 2)-H C(sp 3)-H C(sp 3)-H

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Section: ((Author Portrait))mentioning

confidence: 99%

The Fluorination of C−H Bonds: Developments and Perspectives

et al. 2019

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“…4b The role of Selectfluor remains uncertain, but one potential option is that it accelerates the catalytic cycle by formation of a Pd(IV) catalyst, as has been reported by others. 8 , 9 Additional evidence in support of a Pd(IV) mechanism is the observation of a signal at −181 ppm in the 19 F NMR when Pd(OAc) 2 is added to Selectfluor ( 19 F NMR signals for SelectFluor are 48 (N–F) and −151 (BF 4 ) ppm, Supporting Information (SI) ). A more resolved mechanism for this reaction is still being examined and will be published in due course.…”

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confidence: 98%

Development and Utilization of a Palladium-Catalyzed Dehydration of Primary Amides To Form Nitriles

et al. 2018

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A palladium(II) catalyst, in the presence of Selectfluor, enables the efficient and chemoselective transformation of primary amides into nitriles. The amides can be attached to aromatic rings, heteroaromatic rings, or aliphatic side chains, and the reactions tolerate steric bulk and electronic modification. Dehydration of a peptaibol containing three glutamine groups afforded structure–activity relationships for each glutamine residue. Thus, this dehydration can act similarly to an alanine scan for glutamines via synthetic mutation.

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“…The importance of the compound lies in its potential reactivity as a N,O-bidentate directing group in metal-catalyzed C-H bond functionalization reactions. The literature reports studies involving a similar synthesis which suggests the possible formation of the title compound as a possible reaction intermediate or byproduct [12,13]. However, the compound was not isolated, its formation was not confirmed, and neither its characterization by spectroscopic methods nor structure determination have been reported.…”

Section: Introductionmentioning

confidence: 99%

“…However, the compound was not isolated, its formation was not confirmed, and neither its characterization by spectroscopic methods nor structure determination have been reported. Li et al [12] reported Pd-catalyzed C-H fluorination of arenes using oxazolines as removable directing groups. The reported synthesis could have involved the title compound as a possible reaction intermediate or a byproduct.…”

Section: Introductionmentioning

confidence: 99%

N-(2-Hydroxy-1,1-dimethylethyl)-3-methylbenzamide

Mamari

Lawati

2019

Molbank

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The title compound, N-(2-hydroxy-1,1-dimethylethyl)-3-methylbenzamide was synthesized by reacting 3-methylbenzoyl chloride or 3-methylbenzoic acid with 2-amino-2-methyl-1-propanol. In the present report, the synthesized target compound was fully characterized by various spectroscopic methods (1H NMR, 13C NMR, IR, GC-MS), its composition confirmed by elemental analysis, and its structure determined and confirmed by X-ray analysis. The importance of this compound lies in its possession of an N,O-bidentate directing group. Such a structural motif is potentially suitable for metal-catalyzed C–H bond functionalization reactions.

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Palladium-catalyzed electrophilic C–H fluorination of arenes using oxazoline as a removable directing group

Cited by 28 publications

References 18 publications

The Fluorination of C−H Bonds: Developments and Perspectives

The Fluorination of C−H Bonds: Developments and Perspectives

Development and Utilization of a Palladium-Catalyzed Dehydration of Primary Amides To Form Nitriles

N-(2-Hydroxy-1,1-dimethylethyl)-3-methylbenzamide

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