5-endo Heck-type cyclization of 2-(trifluoromethyl)allyl ketone oximes: synthesis of 4-difluoromethylene-substituted 1-pyrrolines

Ichikawa, Junji; Nadano, Ryo; Ito, Naotaka

doi:10.1039/b610690k

Cited by 117 publications

(25 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[51] The formation of exo -difluoromethylene product has been attributed to the β-F elimination (instead of β-H elimination) from alkyl-Pd II intermediate.…”

Section: Aza-heckmentioning

confidence: 99%

Heck‐Like Reactions Involving Heteroatomic Electrophiles

Vulovic

Watson

2017

Eur J Org Chem

View full text Add to dashboard Cite

Since the discovery of the Heck reaction in the early seventies, this reaction has become a powerful tool in synthetic organic chemistry. By employing heteroatomic instead of traditional carbon electrophiles, the Heck reaction shows an intriguing flexibility. These "hetereoatomic-Heck reactions" reinvigorate the area, offering new routes to highly useful synthetic precursors and structural motifs present in biologically active compounds. This microreview focuses on early developments leading to the heteroatomic-Heck reactions (silyl-Heck, boryl-Heck and intramolecular aza-Heck), current state of the emerging area, as well as that of a few related processes.

show abstract

“…[51] The formation of exo -difluoromethylene product has been attributed to the β-F elimination (instead of β-H elimination) from alkyl-Pd II intermediate.…”

Section: Aza-heckmentioning

confidence: 99%

Heck‐Like Reactions Involving Heteroatomic Electrophiles

Vulovic

Watson

2017

Eur J Org Chem

View full text Add to dashboard Cite

show abstract

“…The products were employed to probe the effect of fluorine substitution on the molecular properties and on the arrangement of molecules in the solid state [81]. The absorption spectroscopy showed that 124 and 126 had a λmax at approximately 350 nm, and addition of dimethylaniline to the hexane solutions led to exciplex emission with λmax ranging from 458 to 514 Furthermore, Pd-catalyzed Heck-type cyclization of 2-trifluoromethyl-1-alkenes (118) bearing an O-acyloxime moiety was accomplished (Scheme 23) [45,80]. The reaction represented a rare example of 5-endo mode alkene insertion into transition-metal species via oxidative addition of the N-O bond (119).…”

Section: Other Fluorine-containing Alkenes As the Cross-coupling Reagmentioning

confidence: 99%

“…The wide range of substrates and the good functional group tolerance made this strategy facile and practical for the streamlined synthesis of functional styrenes. Furthermore, Pd-catalyzed Heck-type cyclization of 2-trifluoromethyl-1-alkenes (118) bearing an O-acyloxime moiety was accomplished (Scheme 23) [45,80]. The reaction represented a rare example of 5-endo mode alkene insertion into transition-metal species via oxidative addition of the N-O bond (119).…”

Section: Scheme 17 Preparation Of Diazonium-functionalized Oligo(phementioning

confidence: 99%

“…The results indicated that the CF 3 group played a crucial role in the 5-endo Heck-type cyclization, wherein the trifluoromethyl substituent seemed to activate the vinylic terminal carbon in 118 and stabilize the cyclized palladium intermediate 120. Furthermore, Pd-catalyzed Heck-type cyclization of 2-trifluoromethyl-1-alkenes (118) bearing an O-acyloxime moiety was accomplished (Scheme 23) [45,80]. The reaction represented a rare example of 5-endo mode alkene insertion into transition-metal species via oxidative addition of the N-O bond (119).…”

Section: Other Fluorine-containing Alkenes As the Cross-coupling Reagmentioning

confidence: 99%

See 1 more Smart Citation

Pd-Catalyzed Mizoroki-Heck Reactions Using Fluorine-Containing Agents as the Cross-Coupling Partners

Yang

Zhao

et al. 2018

Catalysts

View full text Add to dashboard Cite

Abstract:The Mizoroki-Heck reaction represents one of the most convenient methods for carbon-carbon double bond formation in the synthesis of small organic molecules, natural products, pharmaceuticals, agrochemicals, and functional materials. Fluorine-containing organic compounds have found wide applications in the research areas of materials and life sciences over the past several decades. The incorporation of fluorine-containing segments into the target molecules by the Mizoroki-Heck reactions is highly attractive, as these reactions efficiently construct carbon-carbon double bonds bearing fluorinated functional groups by simple procedures. This review summarizes the palladium-catalyzed Mizoroki-Heck reactions using various fluorine-containing reagents as the cross-coupling partners. The first part of the review describes the Pd-catalyzed Mizoroki-Heck reactions of aryl halides or pseudo-halides with the fluorinated alkenes, and the second part discusses the Pd-catalyzed Mizoroki-Heck reactions of the fluorinated halides or pseudo-halides with alkenes. Variants of the Pd-catalyzed Mizoroki-Heck reactions with fluorine-containing reagents are also briefly depicted. This work supplies an overview, as well as a guide, to both younger and more established researchers in order to attract more attention and contributions in the realm of Mizoroki-Heck reactions with fluorine-containing participants.

show abstract

“…[4] Both substitutions have been useful in organic syntheses. [5][6][7][8][9] On the basis of the concept of combining these two substitutions, we adopted a simple method of constructing fluorinated ring systems using bifunctional nucleophiles (XH-YH, Scheme 1 C). In the proposed ring constructions, S N 2'type reactions of 2-trifluoromethyl-1-alkenes would proceed with one of the nucleophilic centers (XH-) to give the corresponding 1,1-difluoro-1-alkenes, and the 1,1-difluoro-1alkenes formed would then be subjected to intramolecular S N V reactions with the other nucleophilic moiety (-YH), to give ring-fluorinated cyclic compounds.…”

mentioning

confidence: 99%

Substitution of Two Fluorine Atoms in a Trifluoromethyl Group: Regioselective Synthesis of 3‐Fluoropyrazoles

2012

Self Cite

View full text Add to dashboard Cite

Fluorine atoms in vinylic and allylic positions are highly versatile substituents. [1] Among the compounds bearing these fluorine atoms, 2-trifluoromethyl-1-alkenes and 1,1-difluoro-1-alkenes are attractive as building blocks for organic syntheses. [2] Because these fluoroalkenes are electron-deficient, they inherently react with nucleophiles instead of electrophiles. 2-Trifluoromethyl-1-alkenes are subjected to nucleophilic attack at the carbon atom in the position g with respect to the fluorine substituents (Scheme 1 A). [2] Succes-Supporting information for this article is available on the WWW under http://dx.

show abstract

5-endo Heck-type cyclization of 2-(trifluoromethyl)allyl ketone oximes: synthesis of 4-difluoromethylene-substituted 1-pyrrolines

Abstract: 2-(Trifluoromethyl)allyl ketone O-pentafluorobenzoyloximes undergo a palladium-catalyzed 5-endo mode of alkene insertion via oxidative addition of the N-O bond, followed by beta-fluorine elimination to produce 4-difluoromethylene-1-pyrrolines.

Cited by 117 publications

References 40 publications

Heck‐Like Reactions Involving Heteroatomic Electrophiles

Heck‐Like Reactions Involving Heteroatomic Electrophiles

Pd-Catalyzed Mizoroki-Heck Reactions Using Fluorine-Containing Agents as the Cross-Coupling Partners

Substitution of Two Fluorine Atoms in a Trifluoromethyl Group: Regioselective Synthesis of 3‐Fluoropyrazoles

Contact Info

Product

Resources

About