Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics

• Durbis J. Castillo-Pazos,
• Juan D. Lasso and
• Chao-Jun Li

Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79

• Durbis J. Castillo-Pazos Juan D. Lasso Chao-Jun Li Department of Chemistry and FRQNT Centre for Green Chemistry and Catalysis, McGill University, 801 Sherbrooke Street W, Montreal, Quebec H3A 0B8, Canada 10.3762/bjoc.18.79 Abstract In response to the demand for late-stage perfluoroalkylation in

• , perfluorohexylation, and perfluorobutylation. Keywords: α-(perfluoroalkylsulfonyl)propiophenones; innate functionalization; late-stage functionalization; light-mediated perfluoroalkylation; perfluoroalkyl sulfinates; Introduction Perfluorinated compounds are a family of molecules containing a backbone where all C–H

• . Using 1,3,5-trimethoxybenzene (TMB, 9) as a model substrate, we optimized the perfluoroalkylation reaction under irradiation of a 300 W Xenon arc lamp (Table 2). Based on the UV–vis absorption of our reagents 1, we used long-pass filters at either 280 nm or 295 nm to avoid side reactions caused by

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• perfluoroalkyl iodide form a halogen-bond adduct, and then light-induced electron transfer happens in order to give a perfluoroalkyl radical. The protocol can realize alkene- and alkyne iodide perfluoroalkylation and C–H perfluoroalkylation of electron-rich heteroaromatic hydrocarbons, providing a novel protocol

• ] designed a reaction, with indanone derivatives 65 and perfluorohexyl iodide (66) as substrates and a phase-transfer catalyst (PTC) to give perfluoroalkylation product 67 under white-light irradiation (Scheme 23). A variety of electron-withdrawing substituents on the aromatic ring of 65 were well tolerated

• [32] found a bifunctional group reaction of perfluoroalkylation and β-alkenylation by a perfluoroalkyl radical. Perfluoroalkylation product 93 was synthesized by utilizing (E)-3-methyl-1-phenylhept-1,6-dien-3-ol (92) and perfluorobutyl iodide (28) as substrates and potassium phosphate and DABCO as

Benzothiazolium salts as reagents for the deoxygenative perfluoroalkylthiolation of alcohols

• Armin Ariamajd,
• Nils J. Gerwien,
• Benjamin Schwabe,
• Stefan Dix and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2021, 17, 83–88, doi:10.3762/bjoc.17.8

• the vast majority of cases, the SRF group is not installed as an intact functional group but rather indirectly through perfluoroalkylation of a thiol or sulfide moiety already present on the substrate (Scheme 1a) [15][20][21][22][23][24][25][26]. By contrast, direct perfluoroalkylthiolation, which

• the perfluoroisopropyl species BT-SCF(CF3)2. Each reagent was synthesized according to the two-step procedure shown in Scheme 2. Firstly, MBT was reacted with a perfluoroalkyl iodide and NaH in DMF under irradiation with UVA LEDs (λmax = 365 nm). In all cases, efficient S-perfluoroalkylation was

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• ). The selectivity has been improved further with the development of new PTCs [74][75][76], although the scope of the reaction remains limited. Building on these initial reports, Melchiorre et al. developed a perfluoroalkylation reaction of the same starting materials 159 using alkyl iodides 163 (Scheme

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• reported in the literature. The key advantages of the use of Cu as catalyst are related to its great abundance, as well as its cheap and non-toxic character [14][96][97]. In 2016, Tan, Wang and co-workers developed a methodology allowing the ortho-perfluoroalkylation of benzamides. This reaction

• , ethoxy, trifluoromethyl, nitro, and ester underwent efficiently the desired perfluoroalkylation. This coupling was sensitive to steric hindrance as ortho-substituted substrates were less efficiently converted into the desired products. Furthermore, various perfluoroalkyl iodides with different chain

• perfluoroalkyl benzoic acid derivatives. A plausible mechanism for the perfluoroalkylation of N-(quinolin-8-yl)benzamides is proposed in Figure 34. First, C–H activation of the benzamide substrate with copper produces a cyclometalated complex. Meanwhile, perfluoroalkyl radicals are generated by electron transfer

Copper-based fluorinated reagents for the synthesis of CF₂R-containing molecules (R ≠ F)

• Louise Ruyet and
• Tatiana Besset

Beilstein J. Org. Chem. 2020, 16, 1051–1065, doi:10.3762/bjoc.16.92

• reagents for perfluoroalkylation reactions [66], Hartwig developed in 2011 the (Phen)CuCF3 and (Phen)CuCF2CF2CF3 complexes from inexpensive reagents. Indeed, when mixing (CuOt-Bu)4, 1,10-phenanthroline and the corresponding TMSRF, the perfluoroalkyl copper complexes were isolated for the first time (Scheme

•  14, a). One year later, they demonstrated that these copper-based reagents ((Phen)CuCF2RF, RF = F, CF3 and CF2CF3) were efficient in a two-step sequence reaction (borylation/perfluoroalkylation) allowing the functionalization of either sterically hindered arenes or aryl bromides with the CF2CF3 and

• the functionalization of different classes of compounds (benzyl and vinyl bromides, 4-biphenylboronic acid, phenylacetylene for instance). From these pioneering reports of perfluoroalkylation (trifluoromethylation, pentafluoroethylation and heptafluoropropylation), several groups studied the synthesis

Recent developments in photoredox-catalyzed remote ortho and para C–H bond functionalizations

• Rafia Siddiqui and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26

• the reported procedures. This being the case, in 2013, Itoh and co-workers reported the C–H perfluoroalkylation with photoredox catalyst 7 (Scheme 28), and they obtained the best yields with electron-rich arenes compared to electron-deficient ones [180]. C–H cyanation: synthesis of benzonitrile

• (5a). Monofluorination using QuCN-ClO4 (8). Fluorination with fluorine-18. Aerobic amination with acridinium catalyst 3a. Aerobic aminations with semiconductor photoredox catalyst 18. Perfluoroalkylation of arenes. Synthesis of benzonitriles in the presence of 3a. Acknowledgments We are grateful to

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• perfluoroalkylation of aromatic and heteoaromatic compounds by means of electrolysis [119][120]. Introducing trifluoromethyl and perfluoroalkyl groups (RF) into organic compounds is an important target in organic synthesis because the corresponding fluoroalkylated molecules have received significant interest because

• the presence of photosensitizers. 1,2-Migration of a phenyl group mediated by the visible-light-driven catalytic system composed of 1 and Irdfppy. Ring-expansion reactions mediated by the B12-TiO2 hybrid catalyst with UV-light irradiation. Trifluoromethylation and perfluoroalkylation of aromatic

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• trifluoromethyl radical, providing some selectivity to the process, which indicates that it could be applied to a guided LSF strategy. Itoh and co-workers have described a procedure for the direct C–H perfluoroalkylation of substrates, which can act as fluorous tags. The group utilised the corresponding

Nucleophilic fluoroalkylation/cyclization route to fluorinated phthalides

• Masanori Inaba,
• Tatsuya Sakai,
• Shun Shinada,
• Tsuyuka Sugiishi,
• Yuta Nishina,
• Norio Shibata and
• Hideki Amii

Beilstein J. Org. Chem. 2018, 14, 182–186, doi:10.3762/bjoc.14.12

• . An operational simple procedure for a short-step synthesis of 3-(trifluoromethyl)phthalide is required due to their great potential in a variety of applications. Herein, we wish to report a general and convenient synthesis of 3-(perfluoroalkyl)phthalides 1 by nucleophilic perfluoroalkylation of 2

Progress in copper-catalyzed trifluoromethylation

• Guan-bao Li,
• Chao Zhang,
• Chun Song and
• Yu-dao Ma

Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11

• trifluoromethylation reagents. Review Copper-catalyzed trifluoromethylation of aryl and alkyl halides The first example of copper-promoted perfluoroalkylation of aromatic halides was presented in a US patent 1968 [9]. Since then, the copper-catalyzed trifluoromethylation of aromatic compounds has entered a stage of

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• probed by DFT calculations. Keywords: chlorination; copper mediated perfluoroalkylation; crystal structure; DFT calculations; fluorous; hypervalent iodine; nucleophilic substitution; polar space group; Introduction A number of fluorous alkyl iodides, usually of the formula RfnCH2CH2I or RfnI (Rfn = CF3

Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis

• Flavio Fanelli,
• Giovanna Parisi,
• Leonardo Degennaro and
• Renzo Luisi

Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51

• residence time. Noël optimized, for the first time, a trifluoromethylation of aromatic heterocycles by continuous-flow photoredox catalysis. The process benefited from the use of microreactor technology and readily available photocatalysts. The process was also employable for perfluoroalkylation. The

Carbon–carbon bond cleavage for Cu-mediated aromatic trifluoromethylations and pentafluoroethylations

• Tsuyuka Sugiishi,
• Hideki Amii,
• Kohsuke Aikawa and
• Koichi Mikami

Beilstein J. Org. Chem. 2015, 11, 2661–2670, doi:10.3762/bjoc.11.286

• perfluoroalkyl organometallic reagents (CnF2n+1M) with high reactivity, act as prominent cross-coupling participants in aromatic perfluoroalkylation reactions [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. In order to prepare CnF2n+1Cu species, several

• hemiaminals derived from fluoral (CF3C(OSiMe3)NR2), can generate CnF2n+1Cu via carbon–carbon bond cleavage. Herein we focus on Cu-mediated perfluoroalkylation reactions through which carbon dioxide, the esters, or the N-formylamines are eliminated from the perfluoroalkyl reagents. Review Decarboxylation of

• the decarboxylative trifluoromethylation of aryl halides [37] (Scheme 4). Not only iodobenzene but also 4-bromotoluene was trifluoromethylated by the [(NHC)Cu(TFA)] complex. The perfluoroalkylation reactions mentioned above require a stoichiometric amount of copper reagent, whereas it was found that

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• dissertation research focused on photo-induced reactions of perfluoroalkyl iodides and pentafluoroiodobenzene with arenes, aromatic ethers and amines and heterocycles. These reactions led to the perfluoroalkylation or pentafluorophenylation of the aromatic compounds. One series of reactions involved liquid

Flow microreactor synthesis in organo-fluorine chemistry

• Hideki Amii,
• Aiichiro Nagaki and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2013, 9, 2793–2802, doi:10.3762/bjoc.9.314

• synthesis and reactions of fluorine-containing molecules by the use of flow microreactor systems to overcome long-standing problems in fluorine chemistry. Keywords: defluorination; fluorine; fluorination; flow microreactor; organo-fluorine; perfluoroalkylation; Review Fluorine is a key element in the

• usually prepared by halogen–lithium exchange reactions of perfluoroalkyl halides with alkyllithiums are useful for nucleophilic perfluoroalkylation [78], however they readily undergo β-elimination to form perfluoroalkenes [79]. Flow microreactor systems were proved to be effective for generation and

• perfluoroalkylation by generation of perfluoroalkyllithiums in the presence of electrophiles. Integrated flow microreactor system for perfluoroalkylation by generation of perfluoroalkyllithiums in the absence of electrophiles. Acknowledgements The financial support of the Ministry of Education, Culture, Sports

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

• iron(II) sulfate as catalyst and zinc bis(difluoromethanesulfinate) as the fluoroalkyl transfer reagent. A handful of β-difluoromethylstyrenes were obtained in moderate yields and with complete diastereoselectivity (Scheme 4) [62]. 3 Catalytic perfluoroalkylation The transition metal mediated

• metal-catalyzed perfluoroalkylation of sp2 carbons, vinyl sulfonates represent valuable alternative coupling partners to vinyl halides, given that they can be prepared in a straightforward manner from readily available alcoholic precursors. In 2011, the group of S. L. Buchwald described a catalytic

• the complex with Umemoto’s reagent and completed by reductive elimination of the desired benzotrifluoride (Figure 2). 3.1.3 Perfluoroalkylation by means of C–H activation and a perfluoroalkyl radical-source. In contrast to the studies described above, the group of M. S. Sanford has developed a Pd

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

• -process; perfluoroalkylation; perfluoroalkyl sulfides; SRF-introduction; Review 1. Introduction Perfluoroalkyl sulfides of aromatic and heterocyclic compounds have been an important aspect in the general development of organofluorine chemistry over the last twenty years. Alkyl aryl sulfides containing

• . The halogenation of SAlk-derivatives with subsequent replacement of the halogen atoms by fluorine. The introduction of SRF-moieties into aromatic compounds by both electrophilic and nucleophilic reagents. Various modes of perfluoroalkylation of organosulfur compounds including cationic, anionic

• salts (Scheme 37), although the presence of electron-donating and bulky ortho-substituents in the aromatic ring led to reduced yields. 4. Perfluoroalkylation of aromatic sulfur compounds Perfluoroalkyl iodides have not generally been considered as alkylating agents. Unlike R-X they show anomalous