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DOI: 10.1039/D4OB01134A (Paper) Org. Biomol. Chem., 2024, Advance Article

Direct trifluoromethylselenolations of electron-rich (hetero)aromatic rings with N-trifluoromethylselenolating saccharin†

Guiya Gao‡ , Keyi Xie‡, Minghui Shi, Tao Gao, Zedong Wang, Congcong Zhang* and Zhentao Wang*
College of Chemistry and Material Science, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China. E-mail: cczhang@sdau.edu.cn; wzht423@mail.ustc.edu.cn

Received 8th July 2024 , Accepted 27th August 2024

First published on 29th August 2024

Abstract

A novel, easily synthesizable, shelf-stable electrophilic trifluoromethylselenolating reagent, N-trifluoromethylselenosaccharin, has been developed. This reagent can be synthesized in good yield by a two-step one-pot reaction from BnSeCF3, SO2Cl2, and silver saccharin. N-Trifluoromethylselenosaccharin proves to be an efficient trifluoromethylselenolating reagent, enabling the direct trifluoromethylselenolation of various electron-rich aromatic and heteroaromatic rings under mild reaction conditions. It exhibits excellent chemoselectivity and excellent compatibility with various functional groups, making it suitable for late-stage trifluoromethylselenolation applications in complex natural product and drug synthesis.

Introduction

Due to a very specific set of characteristics possessed by the fluorine atom, fluorinated compounds have recently gained huge interest in various applications.1 Therefore, fluorinated molecules can be used in chemicals, pharmaceuticals, and pesticides.2 More recently, the association of a heteroatom with fluorinated moieties has been proven to impart specific physicochemical properties to molecules, such as high electron-withdrawing characteristics (Hammett constants CF3O: σp = 0.38, σm = 0.35, CF3S: σp = 0.40, σm = 0.50) and high lipophilicity (Hansch lipophilicity parameter CF3O: 1.04, CF3S: 1.44).3 Selenium is widely recognized as an essential oligo-element for living species4 and is present in some endogenous compounds, for example, selenoproteins and selenocysteine.5 Selenium atoms exhibit properties similar to those of sulfur. When selenium atoms are associated with trifluoromethyl, they form CF3Se, exhibiting Hammett constants and Hansch lipophilicity parameters falling between those of CF3O and CF3S.3g,h Hence, the CF3Se group holds significant importance in crafting molecules with unique properties, particularly within the realms of medicinal chemistry and agrochemistry.1c,d As a result, the efficient construction of the CF3Se group in organic synthesis has garnered considerable interest from numerous research groups.

Up to now, remarkable work has been done by numerous groups, and several novel and effective trifluoromethylselenolating reagents have been synthesized, which include [Me4N]SeCF3, MSeCF3 (M = Hg, Ag, Cu), [(bpy)CuSeCF3]2, BT–SeCF3, CF3SeCl, TsSeCF3, etc. These reagents were employed for the successful introduction of the CF3Se group into organic molecules, by nucleophilic, electrophilic, or radical-based mechanisms.6 Meanwhile, multicomponent reactions7 and indirect introduction of CF3Se have also been attempted.8 Compared with the numerous nucleophilic trifluoromethylselenolating reagents, there are rather limited varieties of electrophilic reagents. Direct trifluoromethylselenolation of electron-rich (hetero)aromatic compounds is another effective method for introducing the CF3Se moiety into organic molecules. CF3SeCl, due to its low boiling point, volatility, toxicity, and storage issues, has only limited applications.9 TsSeCF3, first synthesized by Tlili and Billard, is a shelf-stable and easy-to-handle reagent, and is therefore used widely.10 Nevertheless, to obtain good yields, FeCl3 has to be used additionally in direct electrophilic substitution of heterocyclic compounds.10e Therefore, there is a strong desire for the development of an easily manageable and more potent electrophilic trifluoromethylselenolating reagent, which can facilitate electrophilic trifluoromethylselenolation reactions with substituted compounds in a mild and effective manner.

Results and discussion

Inspired by the works of Billard, Tlilid's group10a and Shen's11 group, we attempted to synthesize an electrophilic trifluoromethylselenolation reagent containing a saccharin group.

Initially, sodium saccharin was employed in a reaction with CF3SeCl, which was obtained through the reaction of BnSeCF3 with SO2Cl2. The ratio of sulfonyl chloride to sodium saccharin was variously adjusted; however, the desired product was not obtained (entries 1–4, Table 1). It is known that silver ions can facilitate reactions by reacting with chloride ions to form a silver chloride precipitate, possibly driving the reaction forward. Fortunately, when silver saccharin was used instead of a sodium saccharin salt in the reaction with CF3SeCl, a new compound, N-trifluoromethylselenosaccharin, was obtained as a white solid with a yield of 42% (entry 5, Table 1). Interestingly, this compound could be stored in the fridge for several months without any obvious decomposition. By further adjusting the ratio of BnSeCF3, SO2Cl2, and silver saccharin to 1[thin space (1/6-em)]:[thin space (1/6-em)]1.2[thin space (1/6-em)]:[thin space (1/6-em)]2, the yield could be increased to 80% (entry 7, Table 1).

Table 1 Optimization of the conditions for the synthesis of a novel trifluoromethylselenolating reagent

image file: d4ob01134a-u1.tif
Entry SO2Cl2 (x equiv.) [N] (y equiv.) Yieldc (%)
a Sodium saccharin.b Silver saccharin.c Yields correspond to the isolated products.
1 1.0 2.0 0a
2 1.2 2.4 0a
3 1.2 3.0 0a
4 2.0 4.0 0a
5 1.2 1.2 42b
6 1.2 1.5 42b
7 1.2 2.0 80b
8 1.2 3.0 79b

The applicability of the new trifluoromethylselenolation reagent for electrophilic trifluoromethylselenolation was investigated using anisole as a model substrate (Table 2). Initially, the effects of various solvents on the trifluoromethylselenolation reaction were investigated.

Table 2 Trifluoromethyl selenylation of 5aa under various conditions

image file: d4ob01134a-u2.tif
Entrya 3 (equiv.) Solvent T (°C) Yield (%)b
a Reaction conditions: 3 (0.36 mmol), anisole (0.3 mmol), solvent (2 mL).b Yields correspond to the isolated products.
1 1.2 THF 80 0
2 1.2 Acetone 80 0
3 1.2 MeCN 80 0
4 1.2 DMF 80 0
5 1.2 DCE 80 78
6 1.2 Tol–CF3 80 80
7 1.2 HFIP 80 80
8 1.2 TFE 80 89
9 1.2 TFE 40 94
10 1.2 TFE r.t. 91

Treatment of anisole with 120 mol% N-trifluoromethylselenolating saccharin in THF, acetone, acetonitrile, or DMF at 80 °C did not result in the formation of the expected product (entries 1–4, Table 2). However, when 1,2-dichloroethane was used as the solvent, the corresponding product 5aa was obtained in 78% yield. Further experimentation with different solvents revealed that trifluoroethanol (TFE), known for its weak acidity,12 produced the highest yield (89%) at 80 °C (entries 5–8, Table 2). In the best solvent (TFE), the reaction temperatures were investigated. When the reaction temperature was reduced to 40 °C, the yield of the trifluoromethylselenolating product reached 94%, and when the temperature was further lowered to room temperature, a yield of 91% was achieved (entries 9 and 10, Table 2). Therefore, it was hypothesized that TFE, with its suitable degree of acidity, activated the trifluoromethylselenolation reagent,13 leading to an efficient electrophilic trifluoromethylselenolation reaction. These observations demonstrate that reagent 3 is a potent trifluoromethylselenolation reagent.

Having established the optimal conditions of 120 mol% reagent 3 in TFE at room temperature, the scope and limitations of direct electrophilic trifluoromethylselenolation of (hetero)aromatic rings were investigated in detail (Scheme 1). To our satisfaction, upon mixing (hetero)aromatic substrate 4 with reagent 3 in TFE, the SEAr reaction was observed, affording good to excellent isolated yields, without any additional agents. The aromatic rings bearing electron-donating groups such as MeO-, PhO-, TBSO-, AcNH-, amino, hydroxy, methyl, etc. demonstrated smooth reactivity with reagent 3 at room temperature, affording the corresponding products in high yields. It is noteworthy that electron-rich aromatic compounds require lower temperatures to avoid by-product formation (Scheme 1, 5an, 5av, 5axa, 5axb, 5aza, 5azc). Conversely, electron-deficient substrates did not undergo any reaction even at 80 °C, except 5azb, due to the conjugated electron-donating action of N which makes the electron cloud density of pyrroles greater than that of the benzene ring. By doubling the amount of the reagent, bis-trifluoromethylselenolative products could also be obtained in moderate to excellent yields, as illustrated in Scheme 2 for compounds 5ba–5bj.


image file: d4ob01134a-s1.tif
Scheme 1 Trifluoromethyl selenylation reaction on electron-rich (hetero)aromatic rings. Yields correspond to the isolated products. Reaction conditions: 4 (1.0 equiv.), 3 (1.2 equiv.) and TFE (2 mL), r.t., 12 h; a[thin space (1/6-em)]80 °C, 12 h; b[thin space (1/6-em)]0 °C, 1 h, 2.5 equiv. of 3 was used in 5azc.

image file: d4ob01134a-s2.tif
Scheme 2 Trifluoromethyl selenylation reaction on electron-rich (hetero)aromatic rings. Yields correspond to the isolated products. Reaction conditions: 4 (1.0 equiv.), 3 (1.2 equiv.) and TFE (2 mL), r.t., 12 h; a[thin space (1/6-em)]3 (2.5 equiv.), 40 °C; b[thin space (1/6-em)]3 (2.5 equiv.); c[thin space (1/6-em)]3 (2.5 equiv.), 0 °C, 1 h; d[thin space (1/6-em)]3 (2.5 equiv.) and Tol–CF3 (2 mL), 80 °C, 12 h.

Electron-rich and sterically less hindered moieties can undergo the trifluoromethylselenolation reaction preferentially, indicating the good chemoselectivity and regioselectivity of this reagent, facilitating the selective trifluoromethylselenolation of complex molecules. The structures of products 5bf and 5bi were unambiguously verified by single-crystal X-ray analysis (Scheme 2). In comparison with CF3SeCl, the by-product of N-trifluoromethylselenolating saccharin upon completion of the reaction was saccharin, possessing very weak acidity. This characteristic suggests that reagent 3 may be more suitable for trifluoromethylselenolation reactions involving complex natural products or drugs sensitive to acids, unlike CF3SeCl, which yields HCl as a by-product, possessing strong acidity that could lead to the decomposition of such complex substrates. Furthermore, no additional steps were required, significantly simplifying the workup procedure. To validate this hypothesis, several complex natural substrates and drugs were subjected to the reaction with N-trifluoromethylselenolating saccharin. Fortunately, under mild conditions, the corresponding trifluoromethylselenolating products were produced with good yields and selectivities. For instance, trifluoromethylselenolation of colchicine (Scheme 3, 5ci) selectively occurred at the more electron-rich benzene ring's moiety. Modified ezetimibe (Scheme 3, 5cc), esterified indomethacin (Scheme 3, 5cf), podophyllotoxin (Scheme 3, 5ch), diclofenac methyl ester (Scheme 3, 5ck), imatinib (Scheme 3, 5cl), kinetin (Scheme 3, 5cm), metaxalone (Scheme 3, 5cn), etc. were also substituted under the standard conditions, giving products in good to excellent yields. Trifluoromethylselenolation of 17 β-estradiol resulted in a mixture, with the less sterically hindered product being the major one in a 4[thin space (1/6-em)]:[thin space (1/6-em)]1 ratio. Similarly, when fulvestrant was treated under the same conditions, a mixture was obtained, in a ratio of 2[thin space (1/6-em)]:[thin space (1/6-em)]1. It is noteworthy that trifluoromethylselenolation of 10-hydroxycamptothecin and 7-ethyl-10-hydroxycamptothecin both yielded the C-9 substituted products, showing that the C-9 position was more electron-rich. The above results suggest that N-trifluoromethylselenolating saccharin serves as a potent trifluoromethylselenolation reagent. Its compatibility with mild reaction conditions and excellent tolerance towards functional groups make this protocol highly suitable for late-stage trifluoromethylselenolation of natural products and drugs. The structures of products 5ch and 5ck were conclusively confirmed through single-crystal X-ray analysis (Scheme 3).


image file: d4ob01134a-s3.tif
Scheme 3 Trifluoromethyl selenidation of drug molecules. Yields correspond to the isolated products. Reaction conditions: 4 (1.0 equiv.), 3 (1.2 equiv.) and TFE (2 mL), r.t., 12 h; a[thin space (1/6-em)]0 °C, 1 h; b[thin space (1/6-em)]40 °C, 12 h; c[thin space (1/6-em)]80 °C, 12 h; d[thin space (1/6-em)]3 (2.5 equiv.).

Conclusion

In conclusion, this study presents the synthesis of a novel and stable trifluoromethylselenolation reagent. This reagent can be readily and effectively synthesized, enabling direct electrophilic trifluoromethylselenolation of electron-rich (hetero)aromatic rings in TFE under mild conditions without any additional reagents. This electrophilic reaction is not only efficient and versatile but also highly chemoselective. Furthermore, it demonstrates excellent tolerance towards various functional groups, rendering it highly suitable for the late-stage trifluoromethylselenolation of complex natural products and pharmaceuticals. Further investigations into the application of this new reagent are currently underway in our laboratory.

Author contributions

Guiya Gao: data curation and writing – original draft; Keyi Xie: data curation and writing – original draft; Minghui Shi: investigation; Tao Gao: formal analysis; Zedong Wang: data curation; Congcong Zhang: data curation, funding acquisition and writing – review & editing; and Zhentao Wang: funding acquisition and project administration.

Data availability

The data supporting the findings of this study are available from the corresponding author, Zhentao Wang, upon reasonable request.

Conflicts of interest

There are no conflicts to declare.

Acknowledgements

We thank the National Natural Science Foundation of China Youth Fund (No. 21801190) and the Natural Science Foundation of Shandong Province (No. ZR2020QB034) for the financial support.

References

  1. (a) J. Wang, M. Sánchez-Roselló, J. L. Aceña, C. Pozo, E. S. Alexander, S. Fustero, A. S. Vadim and H. Liu, Fluorine in pharmaceutical industry: fluorine-containing drugs introduced to the market in the last decade, Chem. Rev., 2014, 114, 2432–2506 CrossRef CAS PubMed ; (b) S. Purser, R. M. Peter, S. Swallowb and V. Gouverneur, Fluorine in medicinal chemistry, Chem. Soc. Rev., 2008, 37, 320–330 RSC ; (c) M. Inoue, Y. Sumii and N. Shibata, Contribution of organofluorine compounds to pharmaceuticals, ACS Omega, 2020, 5, 10633–10640 CrossRef CAS PubMed ; (d) Y. Ogawa, E. Tokunaga, O. Kobayashi, K. Hirai and N. Shibata, Current contributions of organofluorine compounds to the agrochemical industry, iScience, 2020, 23, 101467 CrossRef CAS .
  2. (a) M. Hird, Fluorinated liquid crystals–properties and applications, Chem. Soc. Rev., 2007, 36, 2070–2095 RSC ; (b) M. Pagliaro and R. Ciriminna, New fluorinated functional materials, J. Mater. Chem., 2005, 15, 4981–4991 RSC ; (c) A. N. Meanwell, Exploring physicochemical space via a bioisostere of the trifluoromethyl and ethyl groups (BITE): attenuating lipophilicity in fluorinated analogues of Gilenya® for multiple sclerosis, Eur. J. Med. Chem., 2018, 61, 5822–5880 CrossRef ; (d) H. B. Mei, J. L. Han, S. Fustero, M. Medio-Simon, D. M. Sedgwick, C. Santi, R. Ruzziconi and V. A. Soloshonok, Fluorine-containing drugs approved by the FDA in 2018, Chem. – Eur. J., 2019, 25, 11797–11819 CrossRef CAS PubMed ; (e) M. Inoue, Y. Sumii and N. Shibata, Contribution of organofluorine compounds to pharmaceuticals, ACS Omega, 2020, 5, 10633–10640 CrossRef CAS PubMed ; (f) B. M. Johnson, Y. Z. Shu, X. Zhuo and N. A. Meanwell, Metabolic and pharmaceutical aspects of fluorinated compounds, J. Med. Chem., 2020, 63, 6315–6386 CrossRef CAS PubMed ; (g) J.-Q. Chai, X.-B. Wang, K. Yue, S.-T. Hou, F. Jin, Y. Liu, L. Tai, M. Chen and C.-L. Yang, Design, synthesis, antifungal activity, and action mechanism of pyrazole-4-carboxamide derivatives containing oxime ether active fragment as succinate dehydrogenase inhibitors, J. Agric. Food Chem., 2024, 72, 11308–11320 CrossRef CAS ; (h) T. Fujiwara and D. O. Hagan, Successful fluorine-containing herbicide agrochemicals, J. Fluorine Chem., 2014, 167, 16–29 CrossRef CAS ; (i) Y. Ogawa, E. Tokunaga, O. Kobayashi, K. Hirai and N. Shibata, Current contributions of organofluorine compounds to the agrochemical industry, iScience, 2020, 23, 101467–101520 CrossRef CAS ; (j) R. Berger, G. Resnati, P. Metrangolo, E. Weber and J. Hulliger, Organic fluorine compounds: a great opportunity for enhanced materials properties, Chem. Soc. Rev., 2011, 40, 3496–3508 RSC ; (k) B. Améduri, The promising future of fluoropolymers, Macromol. Chem. Phys., 2020, 221, 1900573–1900587 CrossRef ; (l) J. Lv and Y. Cheng, Fluoropolymers in biomedical applications: state-of-the-art and future perspectives, Chem. Soc. Rev., 2021, 50, 5435–5467 RSC ; (m) D. Chopra and T. N. G. Row, Role of organic fluorine in crystal engineering, CrystEngComm, 2011, 13, 2175–2186 RSC .
  3. (a) F. R. Leroux, B. Manteau, J. P. Vors and S. Pazenok, Trifluoromethyl ethers–synthesis and properties of an unusual substituent, Beilstein J. Org. Chem., 2008, 4, 13–28 CrossRef PubMed ; (b) F. Toulgoat, S. Alazet and T. Billard, Direct trifluoromethylthiolation reactions: the “renaissance” of an old concept, Eur. J. Org. Chem., 2014, 2415–2428 CrossRef CAS ; (c) X. H. Xu, K. Matsuzaki and N. Shibata, Synthetic Methods for Compounds Having CF3–S Units on Carbon by Trifluoromethylation, Trifluoromethylthiolation, Triflylation, and Related Reactions, Chem. Rev., 2015, 115, 731–764 CrossRef CAS ; (d) T. Besset, P. Jubault, X. Pannecoucke and T. Poisson, New entries toward the synthesis of OCF3-containing molecules, Org. Chem. Front., 2016, 3, 1004–1010 RSC ; (e) A. Tlili, F. Toulgoat and T. Billard, Synthetic Approaches to Trifluoromethoxy-Substituted Compounds, Angew. Chem., Int. Ed., 2016, 55, 11726–11735 CrossRef CAS ; (f) F. Toulgoat and T. Billard, Tri-and difluoromethoxylated N-based heterocycles– Synthesis and insecticidal activity of novel F3CO-and F2HCO-analogues of Imidacloprid and Thiacloprid, Prog. Fluorine Sci., 2017, 3, 141 Search PubMed ; (g) C. Hansch, A. Leo and R. W. Taft, A survey of hammett substituent constants and resonance and field parameters, Chem. Rev., 1991, 91, 165–195 CrossRef CAS ; (h) Q. Glenadel, E. Ismalaj and T. Billard, Electrophilic Trifluoromethyl- and Fluoroalkylseleno-lation of Organometallic Reagents, Eur. J. Org. Chem., 2017, 530–533 CrossRef CAS .
  4. (a) M. P. Rayman, The importance of selenium to human health, Lancet, 2000, 356, 233–241 CrossRef CAS ; (b) K. Schwarz and C. M. Foltz, Selenium as an integral part of factor 3 against dietary necrotic liver degeneration, J. Am. Chem. Soc., 1957, 79, 3292–3293 CrossRef CAS .
  5. (a) M. Bodnar, P. Konieczka and J. Namiesnik, Prostate Cancer, Nutrition, and Dietary Supplements, J. Environ. Sci. Health, Part C: Environ. Carcinog. Ecotoxicol. Rev., 2012, 30, 225–252 CrossRef CAS PubMed ; (b) K. M. Brown and J. R. Arthur, Selenium, selenoproteins and human health: a review, Public Health Nutr., 2001, 4, 593 CrossRef CAS ; (c) D. H. Holben and A. M. Smith, The diverse role of selenium within selenoproteins: a review, J. Am. Diet. Assoc., 1999, 99, 836 CrossRef CAS PubMed ; (d) A. Kyriakopoulos and D. Behne, Selenium-containing proteins in mammals and other forms of life, Rev. Physiol., Biochem. Pharmacol., 2002, 145, 1–46 CAS ; (e) J. Lu and A. Holmgren, Selenoproteins, J. Biol. Chem., 2009, 284, 723–727 CrossRef CAS PubMed ; (f) L. A. Wessjohann, A. Schneider, M. Abbas and W. Brandt, Selenium in chemistry and biochemistry in comparison to sulfur, Biol. Chem., 2007, 388, 997–1006 CrossRef CAS PubMed .
  6. (a) D. E. Yerien, S. Barata-Vallejo and A. Postigo, New visible light organo(metal)-photocatalyzed fluoroalkylsulfanylation (RFS-) and fluoroalkylselenolation (RFSe-) reactions of organic substrates, J. Fluorine Chem., 2020, 240, 109652–109675 CrossRef CAS ; (b) A. Hassanpour, M. R. P. Heravi, A. Ebadi, A. Hosseinian and E. Vessally, Oxidative Trifluoromethyl(thiol/selenol)ation of Terminal Alkynes: An Overview, J. Fluorine Chem., 2021, 245, 109762–109775 CrossRef CAS ; (c) Y. Cao, N. Y. Xu, A. Lasshakov, A. G. Ebadi, M. R. P. Heravi and E. Vessally, Recent advances in direct trifluoromethyl-lselenolation of C–H bonds, J. Fluorine Chem., 2020, 252, 109901–109914 CrossRef ; (d) Y. N. Wang, Z. G. Ye, H. Zhang and Z. L. Yuan, Recent advances in the development of direct trifluoromethylselenolation reagents and methods, Adv. Synth. Catal., 2021, 363, 1835–1854 CrossRef CAS ; (e) X. H. Yang, D. H. Chang, R. Zhao and L. Shi, Recent Advances and Uses of (Me4N)XCF3 (X=S, Se) in the Synthesis of Trifluoromethylthiolated and Trifluoromethyl-selenolated Compounds, Asian J. Org. Chem., 2021, 10, 61–73 CrossRef CAS ; (f) C. J. Zhang, Recent progress toward trifluoromethylselenolation reactions, Chin. Chem. Soc., 2017, 64, 457–463 CrossRef CAS ; (g) C. Ghiazza and A. Tlili, Copper-promoted/copper-catalyzed trifluoromethylselenolation reactions, Beilstein J. Org. Chem., 2020, 16, 305–316 CrossRef CAS ; (h) A. Tlili, E. Ismalaj, Q. Glenadel, C. Ghiazza and T. Billard, Synthetic approaches to trifluoromethylselenolated compounds, Chem. – Eur. J., 2018, 24, 3659–3670 CrossRef CAS PubMed ; (i) G. M. Li and D. Q. Sun, ecent Advances of Direct Incorporation of Fluorine-Containing Groups and 18F-Labeling Methods, Chin. J. Org. Chem., 2016, 36, 1715–1740 CrossRef CAS ; (j) P. P. Nair, R. M. Philip and G. Anilkumar, Nickel-catalysed fluoromethylation reactions, Catal. Sci. Technol., 2021, 11, 6317–6329 RSC ; (k) Z. Z. Han and C. P. Zhang, Fluorination and fluoroalkylation reactions mediated by hypervalent iodine reagents, Adv. Synth. Catal., 2020, 362, 4256–4292 CrossRef CAS ; (l) C. Ghiazza, T. Billard and A. Tlili, Merging Visible-Light Catalysis for the Direct Late-Stage Group-16-Trifluoromethyl Bond Formation, Chem. – Eur. J., 2019, 25, 6482–6495 CrossRef CAS PubMed ; (m) J. Y. Liu, M. M. Tian, A. K. Li, L. S. Ji, D. Qiu and X. Zhao, Acid-promoted selective synthesis of trifluoromethylselenolated benzofurans with Se-(trifluoromethyl) 4-methylbenzenesulf-onoselenoate, Tetrahedron Lett., 2021, 66, 152809–152813 CrossRef CAS ; (n) K. L. Tan, H. N. Wang, T. Dong and C. P. Zhang, Trifluoromethyl-selenolation and N-acylation of indoles with [Me4N][SeCF3], Org. Biomol. Chem., 2021, 19, 5368–5376 RSC ; (o) D. Louvel, C. Ghiazza, V. Debrauwer, L. Khrouz, C. Monnereau and A. Tlili, Forging C-SeCF3 Bonds with Trifluoromethyl Tolueneselenosulfonate under Visible-Light, Chem. Rec., 2021, 21, 417–426 CrossRef CAS ; (p) K. Grollier, A. De Zordo-Banliat, F. Bourdreux, B. Pegot, G. Dagousset, E. Magnier and T. Billard, Chem. – Eur. J., 2021, 27, 6028–6033 CrossRef CAS ; (q) M. Tironi, S. Dix and M. N. Hopkinson, Deoxygenative nucleophilic difluoromethylsele-nylation of carboxylic acids and alcohols with BT-SeCF 2 H, Org. Chem. Front., 2021, 8, 6026–6031 RSC ; (r) Z. Z. Han, T. Dong, X. X. Ming, F. Kuang and C. P. Zhang, Synthesis and Biological Evaluation of CF3Se-Substituted α-Amino Acid Derivatives, ChemMedChem, 2021, 16, 3177–3180 CrossRef CAS .
  7. (a) C. H. Chen, C. Q. Hou, Y. G. Wang, T. S. Andy Hor and Z. Q. Weng, Copper-catalyzed trifluoromethylselenolation of aryl and alkyl halides: the silver effect in transmetalation, Org. Lett., 2014, 16, 524–527 CrossRef CAS PubMed ; (b) C. H. Chen, L. Ouyang, Q. F. Lin, Y. L. Liu, C. Q. Hou, Y. F. Yuan and Z. Q. Weng, Synthesis of CuI Trifluoromethylselenates for Trifluoromethylselenolation of Aryl and Alkyl Halides, Chem. – Eur. J., 2014, 20, 657–661 CrossRef CAS PubMed .
  8. (a) T. Billard and B. R. Langlois, A new simple access to trifluoromethyl thioethers or selenoethers from trifluoromethyl trimethylsilane and disulfides or diselenides, Tetrahedron Lett., 1996, 37, 6865–6868 CrossRef CAS ; (b) S. Large, N. Roques and B. R. Langlois, Nucleophilic Trifluoromethylation of Carbonyl Compounds and Disulfides with Trifluoromethane and Silicon-Containing Bases, J. Org. Chem., 2000, 65, 8848–5886 CrossRef CAS PubMed ; (c) T. Billard, B. R. Langlois and S. Large, Phosphorus, Sulfur Silicon Relat, Phosphorus, Sulfur Silicon Relat. Elem., 1998, 136, 521–524 CrossRef ; (d) T. Billard, S. Large and B. R. Langlois, Preparation of trifluoromethyl sulfides or selenides from trifluoromethyl trimethylsilane and thiocyanates or selenocyanates, Tetrahedron Lett., 1997, 38, 65–68 CrossRef CAS ; (e) S. Potash and S. Rozen, General synthesis of trifluoromethyl selenides utilizing selenocyanates and fluoroform, J. Org. Chem., 2014, 79, 11205–11208 CrossRef CAS PubMed .
  9. (a) J. W. Dale, H. J. Emeléus and R. N. Haszeldine, Organometallic and organometalloidal fluorine compounds. Part XIV. Trifluoromethyl derivatives of selenium, J. Chem. Soc., 1958, 2939–2945 RSC ; (b) E. Magnier and C. Wakselman, A mild and practical preparation of trifluoromethaneselenenyl chloride, Collect. Czech. Chem. Commun., 2002, 67, 1262–1266 CrossRef CAS .
  10. (a) Q. Glenadel, C. Ghiazza, A. Tlili and T. Billard, Copper-Catalyzed Direct Trifluoro-and Perfluoroalkylselenolations of Boronic Acids with a Shelf-Stable Family of Reagents, Adv. Synth. Catal., 2017, 359, 3414–3420 CrossRef CAS ; (b) C. Ghiazza, M. Ndiaye, A. Hamdi, A. Tlili and T. Billard, Regioselective remote CH fluoroalkyl-selenolation of 8-aminoquinolines, Tetrahedron, 2018, 74, 6521–6526 CrossRef CAS ; (c) C. Ghiazza, V. Debrauwer, T. Billard and A. Tlili, Exploring the reactivity of trifluoromethyl tolueneselenosulfonate with alkynes under copper catalysis, Chem. – Eur. J., 2018, 24, 97–100 CrossRef CAS PubMed ; (d) C. Ghiazza, L. Khrouz, C. Monnereau, T. Billard and A. Tlili, Visible-light promoted fluoroalkylselenolation: toward the reactivity of unsaturated compounds, Chem. Commun., 2018, 54, 9909–9912 RSC ; (e) X. Zhao, X. F. Wei, M. M. Tian, X. C. Zheng, L. S. Ji, Q. Li, Y. H. Lin and K. Lu, Ferric chloride-promoted direct trifluoromethyl-lselenolation of nitrogen-containing heterocyclic compounds by Se-(trifluoromethyl) 4-methylbenzenesulfono-selenoate in water, Tetrahedron Lett., 2019, 60, 1796–1799 CrossRef CAS ; (f) C. Ghiazza, A. Tlili and T. Billard, Electrophilic trifluoromethyl-lselenolation of terminal alkynes with Se-(trifluoromethyl) 4-methylbenzenesul-fonoselenoate, Beilstein J. Org. Chem., 2017, 13, 2626–2630 CrossRef CAS ; (g) K. Grollier, A. Taponard, C. Ghiazza, R. Magnier and T. Billard, Environmentally Compatible Access to α-Trifluoromethyl-seleno-Enones, Helv. Chim. Acta, 2020, 103, e2000185 CrossRef CAS ; (h) Z. Wu, Y. H. Xu, J. G. Liu, X. X. Wu and C. Zhu, A practical Access to Fluoroalkylthio (seleno)-functionalized Bicyclo [1.1.1] pentanes, Sci. China: Chem., 2020, 63, 1025–1029 CrossRef CAS ; (i) C. Ghiazza, V. Debrauwer, C. Monnereau, L. Khrouz, M. Medebielle, T. Billard and A. Tlili, Visible-Light-Mediated Metal-Free Synthesis of Trifluoromethylselenolated Arenes, Angew. Chem., Int. Ed., 2018, 57, 11781–11785 CrossRef CAS ; (j) C. Ghiazza, L. Khrouz, T. Billard, C. Monnereau and A. Tlili, Fluoroalkylselenolation of Alkyl Silanes/Trifluoroborates under Metal-Free Visible-Light Photoredox Catalysis, Eur. J. Org. Chem., 2020, 1559–1566 CrossRef CAS ; (k) K. Grollier, E. Chefdeville, E. Jeanneau and T. Billard, Aromatic Trifluoromethylselenolation via Pd-catalyzed CH functi-onalization, Chem. – Eur. J., 2021, 27, 1–8 CrossRef ; (l) K. Grollier, A. D. Zordo-Banliat, F. Bourdreux, B. Pegot, G. Dagousset, E. Magnier and T. Billard, (Trifluoromethylselenyl) methylchalcogenyl as emerging fluorinated groups: synthesis under photoredox catalysis and determination of the lipophilicity, Chem. – Eur. J., 2021, 27, 6028–6033 CrossRef CAS ; (m) D. Louvel, C. Ghiazza, V. Debrauwer, L. Khrouz, C. Monnereau and A. Tlili, Forging C-SeCF3 Bonds with Trifluoromethyl Tolueneselenosu-lfonate under Visible-Light, Chem. Rec., 2021, 21, 417–426 CrossRef CAS ; (n) C. Ghiazza, A. Kataria, A. Tlili, F. Toulgoat and T. Billard, Umpolung Reactivity of Fluoroalkylselenotoluenesulfonates: Towards a Versatile Reagent, Asian J. Org. Chem., 2019, 8, 675–678 CrossRef CAS ; (o) K. Grollier, A. Taponard, A. D. Zordo-Banliat, E. Magnier and T. Billard, Metal-free nucleophilic trifluoromethylselenolation via an iodide-mediated umpolung reactivity of trifluoromethyl-lselenotoluene-sulfonate, Beilstein J. Org. Chem., 2020, 16, 3032–3037 CrossRef CAS PubMed ; (p) K. Grollier, E. Chefdeville, A. D. Zordo-Banliat, B. Pegot, G. Dagousset, E. Magnier and T. Billard, Fe-mediated nucleophilic trifluoromethyl-lselenolation of activated alkyl bromides via umpolung reactivity of trifluoromethyl toluenes, Tetrahedron, 2021, 100, 132498–132503 CrossRef CAS .
  11. C. F. Xu and Q. L. Shen, Palladium-catalyzed trifluoromethylthiolation of aryl C-H bonds, Org. Lett., 2014, 16, 2046–2049 CrossRef CAS PubMed .
  12. (a) A. Dandia, R. Singh, J. Joshi and S. Kumari, 2, 2, 2-Trifluoroethanol as green solvent in organic synthesis: A review, Mini-Rev. Org. Chem., 2014, 11, 462–476 CrossRef CAS ; (b) M. Yamashita, K. Shimizu, Y. Koizumi, T. Wakimoto, Y. Hamashima, T. Asakawa, M. Inai and T. Kan, Concise Synthesis of Anserine: Efficient Solvent Tuning in Asymmetric Hydrogenation Reaction, Synlett, 2016, 2734–2736 CAS ; (c) A. Heydari, S. Khaksar and M. Tajbakhsh, Trifluo-roethanol as a metal-free, homogeneous and recyclable medium for the efficient one-pot synthesis of α-amino nitriles and α-amino phosphonates, Tetrahedron Lett., 2009, 50, 77–80 CrossRef CAS .
  13. (a) B. Carbain, C. R. Coxon, H. Lebraud, K. J. Elliott, C. J. Matheson, E. Meschini, A. R. Roberts, D. M. Turner, C. Wong, C. Cano, R. J. Griffin, I. Hardcastle and B. T. Golding, Trifluoroacetic Acid in 2,2,2-Trifluoroethanol Facilitates SNAr Reactions of Heter-ocycles with Arylamines, Chem. – Eur. J., 2014, 20, 2311–2317 CrossRef CAS PubMed ; (b) L. Han, Y. Feng, M. Luo, Z. H. Yuan, X. S. Shao, X. Y. Xu and Z. Li, 2, 2, 2-Trifluoroethanol activated one-pot Mannich-like reaction of β-nitroenamines, secondary amines, and aromatic aldehydes, Tetrahedron Lett., 2016, 57, 2727–2731 CrossRef CAS ; (c) A. Fedotova, E. Kondrashov, J. Legros, J. Maddaluno and A. Y. Rulev, Solvent effects in the aza-Michael addition of anilines, C. R. Chim., 2018, 21, 639–643 CrossRef CAS ; (d) S. Khaksar and S. M. Talesh, Three-component one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives in 2,2,2-trifluoroethanol, C. R. Chim., 2012, 15, 779–783 CrossRef CAS ; (e) S. Y. Lu, W. B. Chen and Q. L. Shen, Friedel-Crafts trifluoromethyl-lthiolation of electron-rich (hetero) arenes with trifluoromethylthio-saccharin in 2, 2, 2-trifluoroethanol (TFE), Chin. Chem. Lett., 2019, 30, 2279–2281 CrossRef CAS ; (f) H. Shigehisa, H. Kikuchi and K. Hiroya, Markovnikov-selective addition of fluorous solvents to unactivated olefins using a Co catalyst, Chem. Pharm. Bull., 2016, 64, 371–374 CrossRef CAS PubMed .

Footnotes

† Electronic supplementary information (ESI) available. CCDC 2363156, 2363182, 2363183 and 2363185. For ESI and crystallographic data in CIF or other electronic format see DOI: https://doi.org/10.1039/d4ob01134a
‡ Co-first authors.
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