Chemo-, Regio-, and Stereoselective Access to (E)-Boryl-Substituted Allyl Fluorides via Electrophilic Fluorodesilylation

Abstract

Herein, we report a transition-metal-free chemo-, regio-, and stereoselective electrophilic fluorodesilylation of α-silyl-substituted allylboronate esters. α-Silyl-substituted allylboronate esters can be chemoselectively coupled with Selectfluor, resulting in a variety of (E)-boryl-substituted allyl fluorides in good yields with γ- and (E)-selectivities. The utilities of the obtained (E)-boryl-substituted allyl fluorides are highlighted by further modifications to afford allyl or alkyl fluoride derivatives.

Key words

allyl fluorides - chemoselectivity - fluorodesilylation - regio­selectivity - stereoselectivity

• References and Notes

• 1a Müller K, Faeh C, Diederich F. Science 2007; 317: 1881
• 1b Hagmann WK. J. Med. Chem. 2008; 51: 4359
• 1c Purser S, Moore PR, Swallow S, Gouverneur V. Chem. Soc. Rev. 2008; 37: 320
• 1d Wang J, Sánchez-Roselló M, Aceña JL, Pozo CD, Sorochinsky AE, Fustero S, Soloshonok VA, Liu H. Chem. Rev. 2014; 114: 2432
• 2 Khan MO. F, Lee HJ. Chem. Rev. 2008; 108: 5131
• 3 Pacheco MC, Purser S, Gouverneur V. Chem. Rev. 2008; 108: 1943
• 4a Middleton WJ. J. Org. Chem. 1975; 40: 574
• 4b Munyemana F, Frisque-Hesbain A.-M, Devos A, Ghosez L. Tetrahedron Lett. 1989; 30: 3077
• 4c Kozikowski AP, Wu J.-P. Tetrahedron Lett. 1990; 31: 4309
• 5a Hollingworth C, Gouverneur V. Chem. Commun. 2012; 48: 2929
• 5b Liang T, Neumann CN, Ritter T. Angew. Chem. Int. Ed. 2013; 52: 8214
• 5c Wu J. Tetrahedron Lett. 2014; 55: 4289
• 5d Yang X, Wu T, Phipps RJ, Toste FD. Chem. Rev. 2015; 115: 826
• 5e Sorlin AM, Usman FO, English CK, Nguyen HM. ACS Catal. 2020; 10: 11980
• 6 Tredwell M, Gouverneur V. Org. Biomol. Chem. 2006; 4: 26
• 7a Greedy B, Paris J.-M, Vidal T, Gouverneur V. Angew. Chem. Int. Ed. 2003; 42: 3291
• 7b Thibaudeau S, Gouverneur V. Org. Lett. 2003; 5: 4891
• 7c Giuffredi G, Bobbio C, Gouverneur V. J. Org. Chem. 2006; 71: 5361
• 7d Purser S, Odell B, Claridge TD. W, Moore PR, Gouverneur V. Chem. Eur. J. 2006; 12: 9176
• 7e Lam Y.-h, Bobbio C, Cooper IR, Gouverneur V. Angew. Chem. Int. Ed. 2007; 46: 5106
• 7f Purser S, Wilson C, Moore PR, Gouverneur V. Synlett 2007; 1166
• 7g Teare H, Robins EG, Årstad E, Luthra SK, Gouverneur V. Chem. Commun. 2007; 2330
• 7h Ishimaru T, Shibata N, Horikawa T, Yasuda N, Nakamura S, Toru T. Angew. Chem. Int. Ed. 2008; 47: 4157
• 7i Purser S, Claridge TD. W, Odell B, Moore PR, Gouverneur V. Org. Lett. 2008; 10: 4263
• 7j Giuffredi GT, Purser S, Sawicki M, Thompson AL, Gouverneur V. Tetrahedron: Asymmetry 2009; 20: 910
• 7k Combettes LE, Lozano O, Gouverneur V. J. Fluor. Chem. 2012; 143: 167
• 8a Panek JS, Yang M. J. Am. Chem. Soc. 1991; 113: 9868
• 8b Masse CE, Panek JS. Chem. Rev. 1995; 95: 1293
• 8c Yus M, González-Gómez JC, Foubelo F. Chem. Rev. 2011; 111: 7774
• 8d Lee JH. Tetrahedron 2020; 76: 131351
• 8e Roberts DD, McLaughlin MG. Adv. Synth. Catal. 2022; 364: 2307
• 9a Park J, Choi S, Lee Y, Cho SH. Org. Lett. 2017; 19: 4054
• 9b Park J, Jung Y, Kim J, Lee E, Lee SY, Cho SH. Adv. Synth. Catal. 2021; 363: 2371
• 9c Jung Y, Yoo SY, Jin Y, Yu J, Han S, Yu J, Park Y, Cho SH. Angew. Chem. Int. Ed. 2023; in press
• 10 The electrophilic fluorination of α-silyl-substituted allylboronate ester 1m with 2a did not yield the desired product 3m. Instead, we observed that the starting material 1m was fully decomposed under the reaction conditions (Scheme 4).
• 11a Wu J, Lorenzo P, Zhong S, Ali M, Butts CP, Myers EL, Aggarwal VK. Nature 2017; 547: 436
• 11b André-Joyaux E, Kuzovlev A, Tappin ND. C, Renaud P. Angew. Chem. Int. Ed. 2020; 59: 13859
• 11c Wang S, Zhang J, Kong L, Tan Z, Bai Y, Zhu G. Org. Lett. 2018; 20: 5631
• 12 Typical Procedure for the Preparation of Product 3a: In a nitrogen-filled glovebox, Selectfluor 2a (71 mg, 0.20 mmol) and anhydrous acetonitrile (1.0 mL) were added to an oven-dried 4.0 mL dram vial equipped with a Teflon-coated magnetic stirrer bar. The vial was removed from the glovebox and cooled to 0 °C. (E)-Trimethyl(1-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)but-2-en-1-yl) (1a, 0.24 mmol, 1.2 equiv) in anhydrous acetonitrile solution (1.0 mL) was added dropwise to the solution, under an argon atmosphere. The reaction mixture was stirred at 0 °C for 12 h and then passed through a short pad of celite and washed with CH₂Cl₂ (50 mL). The filtrate was concentrated under reduced pressure. The ¹H NMR yield was determined by using anisole as an internal standard (96%). The crude mixture was purified by column chromatography on silica gel (n-hexane/Et₂O = 80:1 to 20:1) to give the corresponding product 3a as a light yellow oil (33 mg, 83%, E/Z = 13:1). ¹H NMR (500 MHz, CDCl₃): δ = 6.64–6.57 (ddd, J = 18.2, 16.4, 4.6 Hz, 1 H), 5.70–5.65 (m, 1 H), 5.16–5.02 (m, 1 H), 1.43–1.37 (dd, J = 23.7, 6.5 Hz, 3 H), 1.27 (s, 12 H). ¹³C NMR (126 MHz, CDCl₃): δ = 151.2 (d, J = 19.7 Hz), 90.4 (d, J = 167.1 Hz), 83.6, 24.9 (24.91), 24.9 (24.90), 20.9 (d, J = 23.5 Hz). ¹¹B NMR (161 MHz, CDCl₃): δ = 29.8. ¹⁹F NMR (471 MHz, CDCl₃): δ = –167.8 (minor isomer), –172.7 (major isomer).