Enantioselective assembly of chiral-perfluoroalkyl boranes bearing vicinal boron/carbon stereogenic centers via copper catalysis
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Enantioselective assembly of chiral-perfluoroalkyl boranes bearing vicinal boron/carbon stereogenic centers via copper catalysis

Xinping Cai
1
,
Junyi Jia
1
,
Bofan Feng
1
,
Guan Zhang
1
,
Longlong Li
1
,
Bo-Han Zhu
1,*
,
Qiuling Song
1,2,3,4,*
*Correspondence to: Bo-Han Zhu, Key Laboratory of Molecule Synthesis and Function Discovery, Fujian Province University, College of Chemistry, State Key Laboratory of Green and Efficient Development of Phosphorus Resources, Fuzhou University, Fuzhou 350108, Fujian, China. E-mail: bohanzhu@fzu.edu.cn
Qiuling Song, Key Laboratory of Molecule Synthesis and Function Discovery, Fujian Province University, College of Chemistry, State Key Laboratory of Green and Efficient Development of Phosphorus Resources, Fuzhou University, Fuzhou 350108, Fujian, China. E-mail: qsong@fzu.edu.cn
Chiral Chem. 2027;3:202639. 10.70401/cc.2026.0043
Received: August 20, 2026Accepted: October 15, 2026Published: October 15, 2026
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This manuscript is made available in its unedited form to allow early access to the reported findings. Further editing will be completed before final publication. As such, the content may include errors, and standard legal disclaimers are applicable.

Abstract

Enantioselective assembly of chiral α-perfluoroalkylated organoboron compounds is a significant challenge in synthetic chemistry. Herein, a copper-catalyzed asymmetric B-H insertion reaction was employed to 2-arylpyridine-boranes with α-aryl-α-perfluoroalky diazomethanes, delivering over 40 novel chiral α-perfluoroalkylated organoboron compounds bearing boron/carbon vicinal stereogenic centers. This protocol accommodates a range of perfluoroalkyl substituents including CF₃, C₂F₅, C₃F₇ and C₄F₉. The reaction affords products in up to 85% yield, 99% ee, and dr >20:1 for longer-chain perfluoroalkyl substrates. Mechanistic insights are provided by deuterium-labeling and KIE experiments, together with reference to previous related precedents. The scalability and further transformations of the reaction products demonstrate their potential usefulness in synthetic community.

Keywords

B-H insertion, chiral organoboron, perfluoroalkylation, asymmetric catalysis, vicinal stereocenters

References

  • 1. Caron S. Where does the fluorine come from? A review on the challenges associated with the synthesis of organofluorine compounds. Org Process Res Dev. 2020;24(4):470-480.
    [DOI]
  • 2. Wang J, Sánchez-Roselló M, Aceña JL, del Pozo C, Sorochinsky AE, Fustero S, et al. Fluorine in pharmaceutical industry: Fluorine-containing drugs introduced to the market in the last decade (2001-2011). Chem Rev. 2014;114(4):2432-2506.
    [DOI] [PubMed]
  • 3. O’Hagan D. Fluorine in health care: Organofluorine containing blockbuster drugs. J Fluor Chem. 2010;131(11):1071-1081.
    [DOI]
  • 4. Purser S, Moore PR, Swallow S, Gouverneur V. Fluorine in medicinal chemistry. Chem Soc Rev. 2008;37(2):320-330.
    [DOI] [PubMed]
  • 5. O’Hagan D. Understanding organofluorine chemistry. An introduction to the C–F bond. Chem Soc Rev. 2008;37(2):308-319.
    [DOI]
  • 6. Inoue M, Sumii Y, Shibata N. Contribution of organofluorine compounds to pharmaceuticals. ACS Omega. 2020;5(19):10633-10640.
    [DOI] [PubMed] [PMC]
  • 7. Prchalová E, Štěpánek O, Smrček S, Kotora M. Medicinal applications of perfluoroalkylated chain-containing compounds. Future Med Chem. 2014;6(10):1201-1229.
    [DOI] [PubMed]
  • 8. Hagmann WK. The many roles for fluorine in medicinal chemistry. J Med Chem. 2008;51(15):4359-4369.
    [DOI] [PubMed]
  • 9. Müller K, Faeh C, Diederich F. Fluorine in pharmaceuticals: Looking beyond intuition. Science. 2007;317(5846):1881-1886.
    [DOI] [PubMed]
  • 10. Hoffman JC, Vaughn KC. Flupoxam induces classic club root morphology but is not a mitotic disrupter herbicide. Pestic Biochem Physiol. 1996;55(1):49-53.
    [DOI] [PubMed]
  • 11. Wakeling AE, Dukes M, Bowler J. A potent specific pure antiestrogen with clinical potential. Cancer Res. 1991;51(15):3867-3873.
  • 12. Osborne CK, Wakeling A, Nicholson RI. Fulvestrant: An oestrogen receptor antagonist with a novel mechanism of action. Br J Cancer. 2004;90(Suppl 1):S2-S6.
    [DOI] [PubMed] [PMC]
  • 13. Mannhold R, Cruciani G, Weber H, Lemoine H, Derix A, Weichel C, et al. 6-Substituted benzopyrans as potassium channel activators: Synthesis, vasodilator properties, and multivariate analysis. J Med Chem. 1999;42(6):981-991.
    [DOI] [PubMed]
  • 14. Taka N, Koga H, Sato H, Ishizawa T, Takahashi T, Imagawa J. 6-Substituted 2, 2-bis(fluoromethyl)-benzopyran-4-carboxamide K+ channel openers. Bioorg Med Chem. 2000;8(6):1393-1405.
    [DOI] [PubMed]
  • 15. Zhang J, Didierlaurent S, Fortin M, Lefrançois D, Uridat E, Vevert JP. Nonpeptide endothelin antagonists: From lower affinity pyrazol-5-ols to higher affinity pyrazole-5-carboxylic acids. Bioorg Med Chem Lett. 2000;10(12):1351-1355.
    [DOI] [PubMed]
  • 16. Biliavska L, Pankivska Y, Povnitsa O, Zagorodnya S, Gudz G, Shermolovich Y. Anti-adenoviral activity of 2-(3-chlorotetrahydrofuran-2-yl)-4-tosyl-5-(perfluoropropyl)-1, 2, 3-triazole. Medicina. 2018;54(5):81.
    [DOI] [PubMed] [PMC]
  • 17. Pedersen OS, Pedersen EB. The flourishing syntheses of non-nucleoside reverse transcriptase inhibitors. Synthesis. 2000;2000(4):479-495.
    [DOI]
  • 18. Ren J, Milton J, Weaver KL, Short SA, Stuart DI, Stammers DK. Structural basis for the resilience of efavirenz (DMP-266) to drug resistance mutations in HIV-1 reverse transcriptase. Structure. 2000;8(10):1089-1094.
    [DOI] [PubMed]
  • 19. Wagenfeld A, Bone W, Schwede W, Fritsch M, Fischer OM, Moeller C. BAY 1002670: A novel, highly potent and selective progesterone receptor modulator for gynaecological therapies. Hum Reprod. 2013;28(8):2253-2264.
    [DOI] [PubMed]
  • 20. Schütt B, Kaiser A, Schultze-Mosgau MH, Seitz C, Bell D, Koch M, et al. Pharmacodynamics and safety of the novel selective progesterone receptor modulator vilaprisan: A double-blind, randomized, placebo-controlled phase 1 trial in healthy women. Hum Reprod. 2016;31(8):1703-1712.
    [DOI]
  • 21. Briand M, Anselmi E, Dagousset G, Magnier E. The revival of enantioselective perfluoroalkylation - update of new synthetic approaches from 2015-2022. Chem Rec. 2023;23(9):e202300114.
    [DOI] [PubMed]
  • 22. Yang X, Wu T, Phipps RJ, Toste FD. Advances in catalytic enantioselective fluorination, mono-, di-, and trifluoromethylation, and trifluoromethylthiolation reactions. Chem Rev. 2015;115(2):826-870.
    [DOI] [PubMed] [PMC]
  • 23. Ma JA, Cahard D. Update 1 of: Asymmetric fluorination, trifluoromethylation, and perfluoroalkylation reactions. Chem Rev. 2008;108(9):PR1-PR43.
    [DOI] [PubMed]
  • 24. Duran J, Moldoveanu VG, Barroso C, Pereira GA, Limburg B, Companyó X. Fluoride-transfer asymmetric allylic alkylation enables regiodivergent, stereoselective cross-electrophile coupling. Angew Chem Int Ed. 2026;65(2):e20513.
    [DOI]
  • 25. Li M, Yuan Y, Harrison W, Zhang Z, Zhao H. Asymmetric photoenzymatic incorporation of fluorinated motifs into olefins. Science. 2024;385(6707):416-421.
    [DOI] [PubMed]
  • 26. Trost BM, Gholami H, Zell D. Palladium-catalyzed asymmetric allylic fluoroalkylation/trifluoromethylation. J Am Chem Soc. 2019;141(29):11446-11451.
    [DOI] [PubMed]
  • 27. Hu XS, Yu JS, Zhou J. Catalytic selective mono- and difluoroalkylation using fluorinated silyl enol ethers. Chem Commun. 2019;55(91):13638-13648.
    [DOI] [PubMed]
  • 28. Gao X, Cheng R, Xiao YL, Wan XL, Zhang X. Copper-catalyzed highly enantioselective difluoroalkylation of secondary propargyl sulfonates with difluoroenoxysilanes. Chem. 2019;5(11):2987-2999.
    [DOI]
  • 29. Gao X, Xiao YL, Wan X, Zhang X. Copper-catalyzed highly stereoselective trifluoromethylation and difluoroalkylation of secondary propargyl sulfonates. Angew Chem Int Ed. 2018;57(12):3187-3191.
    [DOI]
  • 30. Okusu S, Hirano K, Yasuda Y, Tanaka J, Tokunaga E, Fukaya H, et al. Alkynyl cinchona catalysts affect enantioselective trifluoromethylation for efavirenz under metal-free conditions. Org Lett. 2016;18(21):5568-5571.
    [DOI]
  • 31. Richter N, Regni G, Baldinelli L, Leutzsch M, Bistoni G, Fürstner A. Nickel-catalyzed enantioselective coupling reactions of fluorinated sorbamides with aldehydes affording Anti-configured β-di(tri)fluoromethyl alcohol derivatives. J Am Chem Soc. 2026;148(26):27934-27950.
    [DOI] [PubMed] [PMC]
  • 32. Ding D, Chen S, Yin L, Ou WT, Krause JA, Cheng MJ, et al. Synthesis of chiral difluoromethyl cyclopropanes through desymmetric difluoromethylation of cyclopropenes enabled by enantioselective copper catalysis. Nat Synth. 2025;4(9):1118-1127.
    [DOI]
  • 33. Ding D, Yin L, Poore AT, Ho YS, Cheng YH, Hsieh CT, et al. Enantioconvergent copper-catalysed difluoromethylation of alkyl halides. Nat Catal. 2024;7(12):1372-1381.
    [DOI]
  • 34. Wang Y, Wang S, Qiu P, Fang L, Wang K, Zhang Y, et al. Asymmetric α-electrophilic difluoromethylation of β-keto esters by phase transfer catalysis. Org Biomol Chem. 2021;19(21):4788-4795.
    [DOI]
  • 35. Peng L, Wang H, Guo C. Copper-catalyzed enantioselective difluoromethylation of amino acids via difluorocarbene. J Am Chem Soc. 2021;143(17):6376-6381.
    [DOI] [PubMed]
  • 36. Granados A, Rivilla I, Cossío FP, Vallribera A. Lanthanum-catalyzed enantioselective trifluoromethylation by using an electrophilic hypervalent iodine reagent. Chemistry. 2019;25(35):8214-8218.
    [DOI] [PubMed]
  • 37. Kitazume T, Ishikawa N. Ultrasound-promoted selective perfluoroalkylation on the desired position of organic molecules. J Am Chem Soc. 1985;107(18):5186-5191.
    [DOI]
  • 38. Iseki K, Nagai T, Kobayashi Y. Diastereoselective trifluoromethylation of chiral imide enolates with iodotrifluoromethane mediated by triethylborane. Tetrahedron Asymmetry. 1994;5(6):961-974.
    [DOI]
  • 39. Jiang X, Lan Y, Hao Y, Jiang K, He J, Zhu J, et al. Iron photocatalysis via Brønsted acid-unlocked ligand-to-metal charge transfer. Nat Commun. 2024;15:6115.
    [DOI]
  • 40. Wu Y, Jiang Y, Wang F, Wang B, Chen C. Light promoted metal-free regio- and stereoselective isoperfluoropropylation of unactivated alkenes with an i-C3F7-iodine(iii) reagent. Org Chem Front. 2024;11(2):370-379.
    [DOI]
  • 41. Balletti M, Wachsmuth T, di Sabato A, Hartley WC, Melchiorre P. Enantioselective catalytic remote perfluoroalkylation of α-branched enals driven by light. Chem Sci. 2023;14(18):4923-4927.
    [DOI] [PubMed] [PMC]
  • 42. Yang J, Ponra S, Li X, Peters BBC, Massaro L, Zhou T, et al. Catalytic enantioselective synthesis of fluoromethylated stereocenters by asymmetric hydrogenation. Chem Sci. 2022;13(29):8590-8596.
    [DOI]
  • 43. Xu P, Fan W, Chen P, Liu G. Enantioselective radical trifluoromethylation of benzylic C-H bonds via cooperative photoredox and copper catalysis. J Am Chem Soc. 2022;144(30):13468-13474.
    [DOI] [PubMed]
  • 44. Briand M, Thai LD, Bourdreux F, Vanthuyne N, Moreau X, Magnier E, et al. Remote radical trifluoromethylation: A unified approach to the selective synthesis of γ-trifluoromethyl α, β-unsaturated carbonyl compounds. Org Lett. 2022;24(51):9375-9380.
    [DOI] [PubMed]
  • 45. Jiang C, Wang L, Zhang H, Chen P, Guo YL, Liu G. Enantioselective copper-catalyzed trifluoromethylation of benzylic radicals via ring opening of cyclopropanols. Chem. 2020;6(9):2407-2419.
    [DOI]
  • 46. Crisenza GEM, Mazzarella D, Melchiorre P. Synthetic methods driven by the photoactivity of electron donor-acceptor complexes. J Am Chem Soc. 2020;142(12):5461-5476.
    [DOI] [PubMed] [PMC]
  • 47. Huang H, Wang X, Wang J. Research developments of the construction of chiral center based on fluoroalkyl radical reactions. Chin J Org Chem. 2019;39(1):1.
    [DOI]
  • 48. Calvo R, Comas-Vives A, Togni A, Katayev D. Taming radical intermediates for the construction of enantioenriched trifluoromethylated quaternary carbon centers. Angew Chem Int Ed. 2019;58(5):1447-1452.
    [DOI] [PubMed]
  • 49. Woźniak Ł, Murphy JJ, Melchiorre P. Photo-organocatalytic enantioselective perfluoroalkylation of β-ketoesters. J Am Chem Soc. 2015;137(17):5678-5681.
    [DOI] [PubMed] [PMC]
  • 50. Zhang S, Luo X, Fang S, Wu JH, Pan J, Xu Z, et al. Organocatalytic enantioselective [2 + 2] cycloadditions towards chiral fused α-trifluoromethyl azetidines. Org Chem Front. 2025;12(4):1129-1136.
    [DOI]
  • 51. Li YB, Hu DD, Ren WR, Liu H, Wang YL, Li K, et al. Hydrogen bonding interaction enabled asymmetric C─H acylation of trifluoroethanol by dual nickel/photoredox catalysis. Angew Chem Int Ed. 2025;64(21):e202424324.
    [DOI]
  • 52. Lu S, Hu Z, Wang D, Xu T. Halogen-atom transfer enabled catalytic enantioselective coupling to chiral trifluoromethylated alkynes via dual nickel and photocatalysis. Angew Chem Int Ed. 2024;63(28):e202406064.
    [DOI]
  • 53. Xu S, del Pozo J, Romiti F, Fu Y, Mai BK, Morrison RJ, et al. Diastereo- and enantioselective synthesis of compounds with a trifluoromethyl- and fluoro-substituted carbon centre. Nat Chem. 2022;14(12):1459-1469.
    [DOI]
  • 54. Lin D, Chen Y, Dong Z, Pei P, Ji H, Tai L, et al. General and modular access to enantioenriched α-trifluoromethyl ketones via nickel-catalyzed reductive trifluoroalkylation. CCS Chem. 2023;5(6):1386-1397.
    [DOI]
  • 55. Hu M, Tan BB, Ge S. Enantioselective cobalt-catalyzed hydroboration of fluoroalkyl-substituted alkenes to access chiral fluoroalkylboronates. J Am Chem Soc. 2022;144(33):15333-15338.
    [DOI] [PubMed] [PMC]
  • 56. Wu J, Wu H, Li X, Liu X, Zhao Q, Huang G, et al. Copper-catalyzed highly selective protoboration of CF3-containing 1, 3-dienes. Angew Chem Int Ed. 2021;60(37):20376-20382.
    [DOI]
  • 57. Trost BM, Wang Y, Hung CJ. Use of α-trifluoromethyl carbanions for palladium-catalysed asymmetric cycloadditions. Nat Chem. 2020;12(3):294-301.
    [DOI]
  • 58. Battaglia V, Sonsona IG, Pellegrini A, Mazzanti A, Lattanzi A. Installation of trifluoromethylated quaternary carbon stereocenters via asymmetric epoxidation of tetrasubstituted alkenes. Adv Synth Catal. 2025;367(23):e70153.
    [DOI]
  • 59. Yan RJ, Liu BX, Hu Y, Du W, Chen YC. Generation of zwitterionic trifluoromethyl N-allylic ylides and their use in switchable divergent annulations. Chem Commun. 2021;57(72):9056-9059.
    [DOI] [PubMed]
  • 60. Gao YY, Liang YJ, Li G, Li L, Hu ZY, Lin WH, et al. NHC-catalyzed kinetic resolution for the synthesis of boron-stereogenic BODIPYs. ACS Catal. 2025;15(11):9346-9352.
    [DOI]
  • 61. Zu B, Guo Y, Ren LQ, Li Y, He C. Catalytic enantioselective synthesis of boron-stereogenic BODIPYs. Nat Synth. 2023;2(6):564-571.
    [DOI]
  • 62. Guo Y, Zu B, Du Chen C, He C. Boron-stereogenic compounds: Synthetic developments and opportunities. Chin J Chem. 2024;42(19):2401-2411.
    [DOI]
  • 63. Liu S, Wu R, Zhu S. Rh(II)-catalyzed enantioselective B-H insertion of cyclic alkyl-donor carbene generated from diynes. Org Lett. 2026;28(13):4258-4263.
    [DOI] [PubMed]
  • 64. Xing Y, Fang Y, Zhao Y, Chen J, Huang Y. Harnessing thia-Rh-carbenes for the enantioselective synthesis of chiral α, α-diheteroatomic carboxylic acids. Nat Catal. 2026;9(2):173-183.
    [DOI]
  • 65. Huang MY, Zhu SF. Uncommon carbene insertion reactions. Chem Sci. 2021;12(48):15790-15801.
    [DOI]
  • 66. Teng MY, Han T, Huang EH, Ye LW. Research progress on enantioselective desymmetrization reactions involving metal carbenes. Chin J Org Chem. 2022;42(10):3295.
    [DOI]
  • 67. Xu W, Yamakawa T, Huang M, Tian P, Jiang Z, Xu MH. Conformational locking induced enantioselective diarylcarbene insertion into B–H and O–H bonds using a cationic Rh(I)/diene catalyst. Angew Chem Int Ed. 2024;63(45):e202412193.
    [DOI]
  • 68. Hyde S, Veliks J, Liégault B, Grassi D, Taillefer M, Gouverneur V. Copper-catalyzed insertion into heteroatom-hydrogen bonds with trifluorodiazoalkanes. Angew Chem Int Ed. 2016;55(11):3785-3789.
    [DOI] [PubMed]
  • 69. Jennifer Kan SB, Huang X, Gumulya Y, Chen K, Arnold FH. Genetically programmed chiral organoborane synthesis. Nature. 2017;552(7683):132-136.
    [DOI]
  • 70. Huang X, Garcia-Borràs M, Miao K, Jennifer Kan SBJ, Zutshi A, Houk KN, et al. A biocatalytic platform for synthesis of chiral α-Trifluoromethylated organoborons. ACS Cent Sci. 2019;5(2):270-276.
    [DOI] [PubMed] [PMC]
  • 71. Zou HN, Huang ML, Huang MY, Su YX, Zhang JW, Zhang XY, et al. Chiral gem-difluoroalkyl reagents: gem-difluoroalkyl propargylic borons and gem-difluoroalkyl α-allenols. Chem Sci. 2023;14(34):9186-9190.
    [DOI] [PubMed] [PMC]
  • 72. Nandakumar M, Rubial B, Noble A, Myers EL, Aggarwal VK. Ring-opening lithiation–borylation of 2-trifluoromethyl oxirane: A route to versatile tertiary trifluoromethyl boronic esters. Angew Chem Int Ed. 2020;59(3):1187-1191.
    [DOI]
  • 73. Jonker SJT, Jayarajan R, Kireilis T, Deliaval M, Eriksson L, Szabó KJ. Organocatalytic synthesis of α-trifluoromethyl allylboronic acids by enantioselective 1, 2-borotropic migration. J Am Chem Soc. 2020;142(51):21254-21259.
    [DOI] [PubMed] [PMC]
  • 74. Jayarajan R, Kireilis T, Eriksson L, Szabó KJ. Asymmetric organocatalytic homologation: Access to diverse chiral trifluoromethyl organoboron species. Chemistry. 2022;28(58):e202202059.
    [DOI] [PubMed] [PMC]
  • 75. Ma X, Kuang Z, Song Q. Recent advances in the construction of fluorinated organoboron compounds. JACS Au. 2022;2(2):261-279.
    [DOI] [PubMed] [PMC]
  • 76. Zhang G, Jia J, Du X, Feng B, Yang K, Yu P, et al. Catalytic asymmetric constructions of nitrogen, boron and carbon continuous stereogenic centers. Nat Commun. 2025;16(1):9955.
    [DOI] [PubMed] [PMC]
  • 77. Zhang G, Zhang Z, Hou M, Cai X, Yang K, Yu P, et al. Construction of boron-stereogenic compounds via enantioselective Cu-catalyzed desymmetric B-H bond insertion reaction. Nat Commun. 2022;13(1):2624.
    [DOI] [PubMed] [PMC]
  • 78. Zhang G, Cai X, Jia J, Feng B, Yang K, Song Q. Cu(I)-catalyzed highly diastereo- and enantioselective constructions of boron/carbon vicinal stereogenic centers via insertion reaction. ACS Catal. 2023;13(14):9502-9508.
    [DOI]
  • 79. Liu JG, Zhang WP, Xu MH. Stereodivergent synthesis of enantioenriched organoboron compounds with carbon/boron dual stereocenters via Rh(I)/Cu(I)-catalyzed enantioselective desymmetrization of B–H insertions. J Am Chem Soc. 2025;147(37):33691-33699.
    [DOI]
  • 80. Pang Y, He Q, Li ZQ, Yang JM, Yu JH, Zhu SF, et al. Rhodium-catalyzed B-H bond insertion reactions of unstabilized diazo compounds generated in situ from tosylhydrazones. J Am Chem Soc. 2018;140(34):10663-10668.
    [DOI] [PubMed]

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Cai X, Jia J, Feng B, Zhang G, Li L, Zhu BH, et al. Enantioselective assembly of chiral-perfluoroalkyl boranes bearing vicinal boron/carbon stereogenic centers via copper catalysis. Chiral Chem. 2027;3:202639. https://doi.org/10.70401/cc.2026.0043

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