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Synlett 2022; 33(17): 1739-1744
DOI: 10.1055/a-1914-1518
DOI: 10.1055/a-1914-1518
letter
Potassium Alkoxide as an Efficient Catalyst for Nucleophilic Perfluoroalkylation: Attempt at Anion-Controlled Enantioselective Insertion of a Trifluoromethyl Group
This work was supported by Grants-in-Aid from the Japan Society for the Promotion of Sciences (JSPS) (Nos. 19H02706 and 19K15548). T.Y. also acknowledges support from the Toyota Riken Scholar Program and the Feasibility Study Program of the Frontier Chemistry Center, Faculty of Engineering, Hokkaido University.
Abstract
Potassium alkoxide was found to be a highly active catalyst for the nucleophilic trifluoromethylation of carbonyl compounds. The catalytic system was successfully applied to the reactions of both aldehydes and ketones, affording the corresponding trifluoromethylated products in high yields at low catalyst loadings (0.1–0.01 mol%) in several solvents, such as THF, toluene, and CH2Cl2. In addition, the potassium salt of a Ru(II) complex bearing an (S)-2,2′-bis[bis(3,5-dimethylphenyl)phosphinyl]-1,1′-binaphthalene [(S)-XylBINAP] ligand and two l-threoninate ligands, prepared in situ, catalyzed the enantioselective trifluoromethylation of aromatic aldehydes, although the ee values were not satisfactory (less than 20%).
Key words
trifluoromethylation - potassium tert-butoxide - ruthenium catalysis - trifluoromethyltrimethylsilane - asymmetric catalysis - carbonyl compoundsSupporting Information
- Supporting information for this article is available online at https://doi.org/10.1055/a-1914-1518.
- Supporting Information
Publication History
Received: 25 June 2022
Accepted after revision: 01 August 2022
Accepted Manuscript online:
01 August 2022
Article published online:
09 September 2022
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References and Notes
- 1a Müller K, Faeh C, Diederich F. Science 2007; 317: 1881
- 1b Purser S, Moore PR, Swallow S, Gouverneur V. Chem. Soc. Rev. 2008; 37: 320
- 2a Ruppert I, Schlich K, Volbach W. Tetrahedron Lett. 1984; 25: 2195
- 2b Prakash GK. S, Krishnamurti R, Olah GA. J. Am. Chem. Soc. 1989; 111: 393
- 2c Krishnamurti R, Bellew DR, Prakash GK. S. J. Org. Chem. 1991; 56: 984
- 2d Liu X, Xu C, Wang M, Liu Q. Chem. Rev. 2015; 115: 683
- 3 Mizuta S, Shibata N, Hibino M, Nagano S, Nakamura S, Toru T. Tetrahedron 2007; 63: 8521
- 4 Prakash GK. S, Panja C, Vaghoo H, Surampudi V, Kultyshev R, Mandal M, Rasul G, Mathew T, Olah GA. J. Org. Chem. 2006; 71: 6806
- 5a Mukaiyama T, Kawano Y, Fujisawa H. Chem. Lett. 2005; 34: 88
- 5b Kawano Y, Kaneko N, Mukaiyama T. Bull. Chem. Soc. Jpn. 2006; 79: 1133
- 6 Cui B, Sun H, Xu Y, Duan L, Li Y.-M. Tetrahedron 2017; 73: 6754
- 7 Mizuta S, Shibata N, Ogawa S, Fujimoto H, Nakamura S, Toru T. Chem. Commun. 2006; 2575
- 8 Mizuta S, Shibata N, Sato T, Fujimoto H, Nakamura S, Toru T. Synlett 2006; 267
- 9 Song JJ, Tan Z, Reeves JT, Gallou F, Yee NK, Senanayake CH. Org. Lett. 2005; 7: 2193
- 10 Matsukawa S, Takahashi S, Takahashi H. Synth. Commun. 2013; 43: 1523
- 11a Dong C, Bai X.-F, Lv J.-Y, Cui Y.-M, Cao J, Zheng Z.-J, Xu L.-W. Molecules 2017; 22: 769
- 11b Kusuda A, Kawai H, Nakamura S, Shibata N. Green Chem. 2009; 11: 1733
- 11c Hatano M, Suzuki S, Takagi E, Ishihara K. Tetrahedron Lett. 2009; 50: 3171
- 11d Matsukawa S, Saijo M. Tetrahedron Lett. 2008; 49: 4655
- 12 Iwanami K, Oriyama T. Synlett 2006; 112
- 13 Komoda K, Shimokawa A, Amii H. ChemistrySelect 2019; 4: 2374
- 14a Billard T, Langlois BR. Eur. J. Org. Chem. 2007; 891
- 14b Shibata N, Mizuta S, Kawai H. Tetrahedron: Asymmetry 2008; 19: 2633
- 14c Zheng Y, Ma J.-A. Adv. Synth. Catal. 2010; 352: 2745
- 14d Valero G, Companyó X, Rios R. Chem. Eur. J. 2011; 17: 2018
- 15a Kuroki Y, Iseki K. Tetrahedron Lett. 1999; 40: 8231
- 15b Kawai H, Kusuda A, Mizuta S, Nakamura S, Funahashi Y, Masuda H, Shibata N. J. Fluorine Chem. 2009; 130: 762
- 16a Iseki K, Nagai T, Kobayashi Y. Tetrahedron Lett. 1994; 35: 3137
- 16b Caron S, Do NM, Arpin P, Larivée A. Synthesis 2003; 1693
- 16c Caron S, Do NM, Sieser JE, Arpin P, Vazquez E. Org. Proc. Res. Dev. 2007; 11: 1015
- 16d Nagao H, Yamane Y, Mukaiyama T. Chem. Lett. 2007; 36: 666
- 16e Nagao H, Kawano Y, Mukaiyama T. Bull. Chem. Soc. Jpn. 2007; 80: 2406
- 17a Mizuta S, Shibata N, Akiti S, Fujimoto H, Nakamura S, Toru T. Org. Lett. 2007; 9: 3707
- 17b Kawai H, Tachi K, Tokunaga E, Shiro M, Shibata N. Org. Lett. 2010; 12: 5104
- 18 Zhao H, Qin B, Liu X, Feng X. Tetrahedron 2007; 63: 6822
- 19 Wu S, Zeng W, Wang Q, Chen F.-X. Org. Biomol. Chem. 2012; 10: 9334
- 20 Hu X, Wang J, Li W, Lin L, Liu X, Feng X. Tetrahedron Lett. 2009; 50: 4378
- 21 Johnston CP, West TH, Dooley RE, Reid M, Jones AB, King EJ, Leach AG, Lloyd-Jones GC. J. Am. Chem. Soc. 2018; 140: 11112
- 22 Zhu and co-workers reported that sodium l-mentholide catalyzed (10 mol%) an enantioselective trifluoromethylation, affording the product in 6% ee; see: Zhu S.-F, Pang W, Xing C.-H, Zhu S.-Z. Chin. J. Chem. 2007; 25: 233
- 23a Kurono N, Arai K, Uemura M, Ohkuma T. Angew. Chem. Int. Ed. 2008; 47: 6643
- 23b Kurono N, Uemura M, Ohkuma T. Eur. J. Org. Chem. 2010; 2010: 1455
- 23c Kurono N, Nii N, Sakaguchi Y, Uemura M, Ohkuma T. Angew. Chem. Int. Ed. 2011; 50: 5541
- 23d Kurono N, Yoshikawa T, Yamasaki M, Ohkuma T. Org. Lett. 2011; 13: 1254
- 23e Uemura M, Kurono N, Sakai Y, Ohkuma T. Adv. Synth. Catal. 2012; 354: 2023
- 23f Uemura M, Kurono N, Ohkuma T. Org. Lett. 2012; 14: 882
- 23g Kurono N, Katayama T, Ohkuma T. Bull. Chem. Soc. Jpn. 2013; 86: 577
- 23h Sakaguchi Y, Kurono N, Yamauchi K, Ohkuma T. Org. Lett. 2014; 16: 808
- 23i Ohkuma T, Kurono N, Sakaguchi Y, Yamauchi K, Yurino T. Adv. Synth. Catal. 2018; 360: 1517
- 24 [1-(4-Bromophenyl)-2,2,2-trifluoroethoxy]-(trimethyl)silane (2a): Typical Procedure All manipulations were performed under an argon atmosphere by using standard Schlenk techniques. 4-Bromobenzaldehyde (1a; 186 mg, 1.00 mmol) was added to a 20 mL Schlenk flask, which was then subjected to three cycles of a vacuum–argon replacement procedure. THF (900 μL) and Me3SiCF3 (173 mg, 1.22 mmol) were added to the reaction vessel, and the resulting solution was degassed by a freeze-drying cycle with purging by argon. The resulting mixture in the flask was placed in a water bath at 30 °C and a 10 mM solution of tBuOK in THF (100 μL) was added. When the reaction was complete [TLC, hexane–EtOAc (5:1)], the reaction was terminated by direct purification by column chromatography (silica gel, EtOAc) to give colorless oil; yield: 325 mg (0.99 mmol, 99%).
- 25 H NMR (400 MHz, CDCl3): δ = 7.52 (d, J = 8.4 Hz, 2 H, Ar–H), 7.34 (d, J = 8.4 Hz, 2 H, Ar–H), 4.88 (q, J = 6.4 Hz, 1 H, F3CCH), 0.1 (s, 9 H, SiMe3). 13C NMR (100 MHz, CDCl3): δ = 134.5, 131.5, 129.2, 123.9 (q, J = 280.8 Hz), 123.3, 72.7 (q, J = 32.5 Hz), –0.3. 19F NMR (376 MHz, CDCl3): δ = –78.4 (d, J = 5.6 Hz).
- 26 (1S)-[1-(4-Bromophenyl)-2,2,2-trifluoroethoxy]-(trimethyl)silane (2a): Typical Procedure A 10 mM solution of KHMDS in toluene (125 μL) was added to a solution of Ru catalyst 4a (1.3 mg, 1.2 μmol) in tBuOMe (625 μL) at –78 °C for 10 min. Then, Me3SiCF3 (67 mg, 0.47 mmol) was added and the mixture was stirred at –78 °C for 15 min. A solution of 4-bromobenzaldehyde (1a; 46 mg, 0.25 mmol) in tBuOMe (500 μL) was poured into the catalyst mixture at –78 °C, and the mixture was allowed to warm to –40 °C. When the reaction was completed, it was terminated by direct purification by column chromatography (silica gel, EtOAc) to give a colorless liquid; yield: 67 mg (0.20 mmol, 82%). TBAF was then added for desilylation of 2a to determine the ee value by chiral GC (Chirasil-Dex-CB; 140 °C): t R (major): 23.7 min [(S)-alcohol; 59.6%], t R (minor): 25.8 min [(R)-alcohol; 40.4%].27
- 27 Huang H, Zong H, Bian G, Song L. J. Org. Chem. 2015; 80: 12614