Use of Trifluoromethyl Groups for Catalytic Benzylation and Alkylation with Subsequent Hydrodefluorination

Zhu, Jianbo; Pérez, Manuel; Caputo, Christopher B.; Stephan, Douglas W.

doi:10.1002/ange.201510494

Cited by 45 publications

(17 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Unlike the activation of other carbon−halogen bonds, C−F functionalization is less developed 2,3 with only a limited number of examples reported to be mediated by main-group species. 4,5 Strong Lewis acids, including BF3, 6 aluminum species, [7][8][9][10][11] low oxidation-state main-group compounds, such as Al(I) or Mg(I) species, 5,[12][13][14][15][16] cationic silicon 17,18 and phosphonium complexes, 19,20 and HF [21][22][23][24] have been used for the functionalization of C−F bonds. These methods either required harsh reaction conditions, or the use of highly reactive species.…”

mentioning

confidence: 99%

Borane-Catalyzed C(sp³)–F Bond Arylation and Esterification Enabled by Transborylation

2021

View full text Add to dashboard Cite

The activation and functionalization of carbon-fluorine bonds represents a significant synthetic challenge given the high thermodynamic barrier to C-F bond cleavage. Stoichiometric hydridoborane-mediated C-F functionalization has recently emerged, but has yet to be rendered catalytic. Herein, the borane-catalyzed coupling of alkyl fluorides with arenes (carbon-carbon bond formation), and carboxylic acids (carbon-oxygen bond formation) has been developed using transborylation reactions to achieve catalytic turnover. Successful C-C and C-O coupling across a variety of structurally and electronically differentiated arenes and carboxylic acids was achieved using 9-borabicyclo[3.3.1]nonane (H-B-9-BBN) as the catalyst and pinacolborane (HBpin), with broad functional group tolerance. Experimental and computational studies suggest a mechanistic dichotomy for the carbon-carbon and carbon-oxygen coupling reactions. B-F transborylation (B−F/B−H metathesis) between F-B-9-BBN and HBpin enabled catalytic turnover for carbon-carbon bond formation whereas direct exchange between the alkyl fluoride and acyloxyboronic ester (C-F/B-O metathesis) was proposed for carbon-oxygen coupling, where H-B-9-BBN catalyzed the dehydrocoupling of the carboxylic acid with HBpin. ASSOCIATED CONTENTThis material is available free of charge via the Internet at http://pubs.acs.org. Crystallographic data (CIF) General experimental; system optimization; substrate synthesis; general reaction setup and procedure; product data; synthesis of reactive intermediates; single-turnover experiments; crystal data and experimental; computational details; NMR spectra; associated references (PDF)

show abstract

mentioning

confidence: 99%

Borane-Catalyzed C(sp³)–F Bond Arylation and Esterification Enabled by Transborylation

2021

View full text Add to dashboard Cite

show abstract

“…Substantial progress has been made with aryl fluorides, while aliphatic substrates continue to be very challenging. Csp 3 ─F bond functionalization has been achieved, for example, with reactive Lewis acids or via hydrogen bond assistance, and used for carbon-heteroatom bond formation (12)(13)(14), carbon-carbon coupling (15)(16)(17)(18)(19)(20), and halide exchange (21)(22)(23). With the exception of allylic, propargylic, and benzylic fluorides (24)(25)(26)(27)(28)(29)(30), low functional group compatibility, limited synthetic utility and competing rearrangement, elimination, or other side reactions, particularly when harsh reaction conditions need to be applied, have remained persistent problems despite some recently reported remarkable advances (31)(32)(33)(34)(35)(36)(37).…”

Section: Introductionmentioning

confidence: 99%

Chemodivergent Csp ³ ─F bond functionalization and cross-electrophile alkyl-alkyl coupling with alkyl fluorides

Balaraman

Wolf

2022

Sci. Adv.

View full text Add to dashboard Cite

The widespread use of fluorinated organic compounds in the health, agrochemical, and materials sciences is sustained by a steadily growing pool of commercially available fine chemicals. The synthetic utility of the increasingly ubiquitous Csp 3 ─F bond, however, remains to be fully exploited, which is often a difficult task because of its paramount stability and chemical inertness. Here, we demonstrate chemodivergent activation of monofluoroalkyl compounds toward either nucleophilic or electrophilic intermediates. This is accomplished under conditions that are compatible with several reaction types and many functional groups, which drastically widens the current scope of organofluorine chemistry and sets the stage for carbon-carbon and carbon-heteroatom bond formations, stereoselective construction of bisoxindole alkaloid scaffolds via in situ Umpolung, and cross-electrophilic coupling methodology. The selective generation of either nucleophilic or electrophilic species and the possibility of doing so simultaneously or, alternatively, switching molecular polarity enable previously unidentified synthetic opportunities that recognize alkyl fluorides as chemodivergent building blocks.

show abstract

“…The compounds of BF3, AlCl3, [CPh3] + , and [SiEt2] 2+ are examples of neutral and cationic Lewis acids with considerable acidity from the vacant p orbitals on central atoms [2][3][4][5][6][7][8][9]. Additionally, PV cations are also commonly used Lewis acids as catalysts for several reactions such as hydrogenations, polymerizations, hydrosilylations, and hydro-defluorinations [10][11][12][13]. Alternatively, PIII compounds are known to behave as Lewis bases due to their electron-donating properties in coordination and catalysis chemistry [14].…”

Section: Introductionmentioning

confidence: 99%

Theoretical Explanation for Catalytic Hydrosilylation of Some Organic Molecules Mediated by a Phosphorus Dication Compound

Yildiz

2021

Eskişehir Teknik Üniversitesi Bilim Ve Teknoloji Dergisi B - Teorik Bilimler

View full text Add to dashboard Cite

Catalysis reactions under metal-free and ambient conditions have received great interest in terms of economic and environmental issues. Especially, the applications of Lewis acids for the processes are having special interest due to their unique roles in a huge number of organic reactions. In this sense, a recent compound PIII dication has played an important role in the catalytic hydrosilylation of carbonyls and olefins. Herein theoretical calculations were carried out to elucidate the mechanisms of the experimentally reported and unknown reactions. The proposed mechanisms show that the reactions of a-d can occur spontaneously, whereas the formation of pyridine has an endergonic nature.

show abstract

Use of Trifluoromethyl Groups for Catalytic Benzylation and Alkylation with Subsequent Hydrodefluorination

Cited by 45 publications

References 50 publications

Borane-Catalyzed C(sp³)–F Bond Arylation and Esterification Enabled by Transborylation

Borane-Catalyzed C(sp³)–F Bond Arylation and Esterification Enabled by Transborylation

Chemodivergent Csp ³ ─F bond functionalization and cross-electrophile alkyl-alkyl coupling with alkyl fluorides

Theoretical Explanation for Catalytic Hydrosilylation of Some Organic Molecules Mediated by a Phosphorus Dication Compound

Contact Info

Product

Resources

About

Use of Trifluoromethyl Groups for Catalytic Benzylation and Alkylation with Subsequent Hydrodefluorination

Cited by 45 publications

References 50 publications

Borane-Catalyzed C(sp3)–F Bond Arylation and Esterification Enabled by Transborylation

Borane-Catalyzed C(sp3)–F Bond Arylation and Esterification Enabled by Transborylation

Chemodivergent Csp 3 ─F bond functionalization and cross-electrophile alkyl-alkyl coupling with alkyl fluorides

Theoretical Explanation for Catalytic Hydrosilylation of Some Organic Molecules Mediated by a Phosphorus Dication Compound

Contact Info

Product

Resources

About

Borane-Catalyzed C(sp³)–F Bond Arylation and Esterification Enabled by Transborylation

Borane-Catalyzed C(sp³)–F Bond Arylation and Esterification Enabled by Transborylation

Chemodivergent Csp ³ ─F bond functionalization and cross-electrophile alkyl-alkyl coupling with alkyl fluorides