Alkenylboronic Ester Activation to Nucleophilic Addition and Electrophilic Trapping with Carbonyl Groups

Dedicated to Professor Masahiro Murakami for his inspiring research career

Abstract

Carbolithiation of (1-phenylvinyl)boronic acid pinacol ester with tert-butyllithium was used to generate α-phenylboryl carbanions that reacted in a straightforward manner with carbonyl groups through a boron–Wittig sequence. When unhindered α,β-unsaturated carbonyl compounds were used, 1,4-addition of the α-phenylboryl carbanions was observed over the boron–Wittig sequence.

Key words

alkenylboronates - alkylideneboranes - boron–Wittig reaction - boron ate suppression - boryl carbanions

Publication History

Received: 02 September 2022

Accepted after revision: 30 September 2022

Accepted Manuscript online:
30 September 2022

Article published online:
02 November 2022

• References and Notes

• 1 Carreras J, Caballero A, Pérez PJ. Chem. Asian J. 2019; 14: 329
• 2 Miyaura N, Satoh M, Suzuki A. Tetrahedron Lett. 1986; 27: 3745
• 3a Brown HC, Lane CF. J. Am. Chem. Soc. 1970; 92: 7212
• 3b Brown HC, Lane CF. J. Am. Chem. Soc. 1971; 93: 1025
• 3c Lane CF, Brown HC. Synthesis 1972; 303
• 4 Chierchia M, Xu P, Lovinger GJ, Morken JP. Angew. Chem. Int. Ed. 2019; 58: 14245
• 5 Wang X.-X, Lu X, He S.-J, Fu Y. Chem. Sci. 2020; 11: 7950
• 6 Campbell MW, Compton JS, Kelly CB, Molander GA. J. Am. Chem. Soc. 2019; 141: 20069
• 7 García-Domínguez A, Mondal R, Nevado C. Angew. Chem. Int. Ed. 2019; 58: 12286
• 8 Mega RS, Duong VK, Noble A, Aggarwal VK. Angew. Chem. Int. Ed. 2020; 59: 4375
• 9 Sun S.-Z, Duan Y, Mega RS, Somerville RJ, Martin R. Angew. Chem. Int. Ed. 2020; 59: 4370
• 10 Kischkewitz M, Okamoto K, Muck-Lichtenfeld C, Studer A. Science 2017; 355: 936
• 11 Tappin ND. C, Gnägi-Lux M, Renaud P. Chem. Eur. J. 2018; 24: 11498
• 12 Zhang L, Lovinger GJ, Edelstein EK, Szymaniak AA, Chierchia MP, Morken JP. Science 2016; 351: 70
• 13 Silvi M, Sandford C, Aggarwal VK. J. Am. Chem. Soc. 2017; 139: 5736
• 14 Brown HC, Dodson VH. J. Am. Chem. Soc. 1957; 79: 2302-2306
• 15 Blount JF, Finocchiaro P, Gust D, Mislow K. J. Am. Chem. Soc. 1973; 95: 7019
• 16 Glogwski E, Zumbulyadis N, Williams JL. R. J. Organomet. Chem. 1982; 231: 97
• 17a Cooke MP. Jr, Widener RK. J. Am. Chem. Soc. 1987; 109: 931
• 17b Cooke MP. Jr. J. Org. Chem. 1994; 59: 2930
• 18a Nakamura M, Hara K, Hatakeyama T, Nakamura E. Org. Lett. 2001; 3: 3137
• 18b Nakamura M, Hatakeyama T, Hara K, Fukudome H, Nakamura E. J. Am. Chem. Soc. 2004; 126: 14344-14345
• 19 González S, Salvado O, Fernández E. Adv. Synth. Catal. 2022; 364: 1701
• 20 Maza RJ, Carbó JJ, Fernández E. Adv. Synth. Catal. 2021; 363: 2274
• 21 Maza RJ, Carbó JJ, Fernández E. Chem. Eur. J. 2021; 27: 12352
• 22 Shimizu H, Igarashi T, Miura T, Murakami M. Angew. Chem. Int. Ed. 2011; 50: 11465
• 23 Cuenca AB, Fernández E. Chem. Soc. Rev. 2021; 50: 72
• 24 Salvado O, Fernández E. Chem. Commun. 2021; 57: 6300
• 25 Palmer WN, Zarate C, Chirik PJ. J. Am. Chem. Soc. 2017; 139: 2589
• 26 Kim C, Roh B, Lee HG. Chem. Sci. 2021; 12: 3668
• 27 Jang WJ, Yun Y. Angew. Chem. Int. Ed. 2019; 58: 18131
• 28 Liang MZ, Meek SJ. J. Am. Chem. Soc. 2020; 142: 9925
• 29 Liang MZ, Meek SJ. Angew. Chem. Int. Ed. 2019; 58: 14234
• 30 1,2-Dicarbofunctionalization through Boron–Wittig Olefination with Aldehydes or Ketones; General Method A flame-dried 100 mL round-bottomed flask equipped with a magnetic stirrer bar was charged with 4,4,5,5-tetramethyl-2-(1-phenylvinyl)-1,3,2-dioxaborolane (1) (69.5 mg, 0.3 mmol, 1.0 equiv) in dried THF (2 mL), then sealed with a rubber septum and placed under a N₂ atmosphere at –78 °C. A 1.7 M solution of t-BuLi in hexane (0.19 mL, 0.33 mmol, 1.1 equiv) was added dropwise and the mixture was stirred for 30 min at –78 °C and then at rt for 16 h. The appropriate aldehyde or ketone (0.45 mmol, 1.5 equiv) was added dropwise and the mixture was stirred for 4 h at rt. Finally, the reaction was quenched with MeOH (5 mL) and the mixture was extracted with Et₂O (×3). The combined organic layers were dried (MgSO₄) filtered through Celite, and concentrated under reduced pressure. The NMR yield was calculated by comparison with an internal standard (naphthalene). The crude product was purified by flash column chromatography. [(1E/1Z)-1-(2,2-Dimethylpropyl)-3-methylbut-1-en-1-yl]benzene (2) Purified by flash column chromatography [silica gel, pentane–EtOAc, (100:0)] to give a colorless liquid; yield: 45.3 mg (70%, E/Z = 1:1). ¹H NMR (400 MHz, CDCl₃): δ = 7.34–7.25 (m, 6 H), 7.25–7.17 (m, 4 H), 5.41 (d, J = 10.0 Hz, 1 H), 5.24 (d, J = 10.1 Hz, 1 H), 2.68 (m, 1 H), 2.50 (s, 2 H), 2.43 (m, 1 H), 2.31 (s, 2 H), 1.03 (d, J = 6.5 Hz, 6 H), 0.95 (d, J = 6.6 Hz, 6 H), 0.79 (s, 9 H), 0.76 (s, 9 H). ¹³C NMR (100 MHz, CDCl₃): δ = 145.7, 142.4, 139.5, 138.1, 135.7, 135.5, 128.1, 127.4, 127.2, 126.3, 125.5, 125.5, 52.6, 41.9, 31.8, 31.4, 29.9, 29.5, 27.7, 27.2, 23.0, 22.5. HRMS (ESI): m/z [M + H]⁺ calcd for C₁₆H₂₅: 217.1956; found: 217.1953.