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Synlett 2018; 29(01): 65-70
DOI: 10.1055/s-0036-1590891
letter
© Georg Thieme Verlag Stuttgart · New York

Iron-Catalyzed C(sp2)–C(sp3) Cross-Coupling Reactions of Di(hetero)arylmanganese Reagents and Primary and Secondary Alkyl Halides

Maximilian S. Hofmayer
a   Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstraße 5–13, Haus F, 81377 München, Germany   Email: Paul.Knochel@cup.uni-muenchen.de
,
Jeffrey M. Hammann
a   Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstraße 5–13, Haus F, 81377 München, Germany   Email: Paul.Knochel@cup.uni-muenchen.de
,
Gérard Cahiez
b   Institut de Recherche de Chimie Paris, CNRS, Chimie ParisTech, 11 Rue Pierre et Marie Curie, 75005 Paris, France
,
Paul Knochel  *
a   Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstraße 5–13, Haus F, 81377 München, Germany   Email: Paul.Knochel@cup.uni-muenchen.de
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Further Information

Publication History

Received: 04 July 2017

Accepted after revision: 03 August 2017

Publication Date:
30 August 2017 (online)

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Abstract

An iron-catalyzed cross-coupling between di(hetero)arylmanganese reagents and primary and secondary alkyl halides is reported. No rearrangement of secondary alkyl halides to unbranched products was observed in these C–C bond-forming reactions.

Key words

iron - catalysis - cross-coupling - manganese - alkyl halides

Supporting Information

    Supporting information for this article is available online at https://doi.org/10.1055/s-0036-1590891.
  • Supporting Information
 

  • References and Notes

  • 2 FeCl2 ca. 375 €/mol, PdCl2 ca. 4500 €/mol; prices retrieved from Alfa Aesar in May 2017.
    • 3a LD50(FeCl2, rat oral) = 900 mg/kg; LD50(NiCl2, rat oral) = 186 mg/kg).
    • 3b Egorova KS. Ananikov VP. Angew. Chem. Int. Ed. 2016; 55: 12150
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  • 7 Hofmayer MS. Hammann JM. Haas D. Knochel P. Org. Lett. 2016; 18: 6456
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  • 9 For detailed information, see the Supporting Information.
  • 10 Wunderlich SH. Kienle M. Knochel P. Angew. Chem. Int. Ed. 2009; 48: 7256
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  • 11 Starting materials were prepared according to literature procedures with only little deviation: Cheung CW. Ren P. Hu X. Org. Lett. 2014; 16: 2566
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  • 12 Typical Procedure for the Iron-Catalyzed Cross-Coupling of Di(hetero)arylmanganese Reagents with Alkyl Halides A dry and argon-flushed 20 mL Schlenk tube, equipped with a stirring bar and a septum, was charged with anhydrous FeCl2 (25 mg, 0.20 mmol, 20 mol%). The alkyl halide (1 mmol, 1.0 equiv) in THF (1 mL) was added, and the mixture was cooled to –20 °C. The di(hetero)arylmanganese reagent (0.7 mmol, 0.7 equiv) was added dropwise, and the mixture was allowed to warm to r.t. overnight. A sat. aq solution of NH4Cl (5 mL) and EtOAc (5 mL) were added, the phases were separated, and the aqueous phase was extracted with EtOAc (3 × 20 mL). The combined organic phases were washed with brine, dried over Na2SO4, and the solvents were evaporated. The residue was subjected to column chromatography purification (SiO2; i-hexane/EtOAc) yielding the corresponding title compound. 1-(3-Isopropylcyclohexyl)-4-methoxybenzene (3b) Following the typical procedure, 1d (252 mg, 1.0 mmol, 1.0 equiv, in 1 mL THF) reacts with di(p-anisyl)manganese (2a, 0.7 mmol, 0.7 equiv) at –20 °C. The solution was allowed to warm to r.t., was stirred for 16 h, and was worked up as usual. The crude product was purified by column chromatography on silica using i-hexane/EtOAc (100:2) as an eluent to afford 3b as a colorless oil (51%, 119 mg, 0.51 mmol, dr = 83:17). 1H NMR (400 MHz, CDCl3): δ = 7.19–7.12 (m, 2 H), 6.90–6.83 (m, 2 H), 3.80 (s, 3 H), 2.48 (tt, J = 11.7, 3.4 Hz, 1 H), 1.95–1.81 (m, 3 H), 1.76 (dtt, J = 11.6, 3.4, 1.8 Hz, 1 H), 1.54–1.33 (m, 3 H), 1.33–1.21 (m, 2 H), 1.12 (dt, J = 12.8, 11.8 Hz, 1 H), 0.90 (dd, J = 6.8, 3.7 Hz, 6 H) ppm. 13C NMR (101 MHz, CDCl3): δ = 157.8, 140.5, 127.8, 113.8, 55.4, 44.6, 44.0, 38.4, 34.7, 33.2, 29.5, 27.0, 20.0, 19.9 ppm. FTIR (ATR): 2954, 2922, 2852, 1512, 1462, 1444, 1244, 1176, 1038, 824, 806 cm–1. MS (EI, 70 eV): m/z (%) = 232 (55), 189 (78), 147 (100), 134 (68), 121 (77). HRMS (EI, 70 eV): m/z calcd for [C16H24O]: 232.1827; found: 232.1821. tert-Butyl{3-[2-fluoro-(1,1′-biphenyl)-4-yl]butoxy}dimethylsilane (3p) Following the typical procedure, tert-butyl(3-iodobutoxy)dimethylsilane (1j, 314 mg, 1.0 mmol, 1.0 equiv, in 1 mL THF) reacts with 2f (0.7 mmol, 0.7 equiv) at –20 °C. The solution was allowed to warm to r.t., was stirred for 16 h, and was worked up as usual. The crude product was purified by column chromatography on silica using i-hexane/EtOAc (100:4) as an eluent to afford 3p as colorless oil (80%, 288 mg, 0.80 mmol). 1H NMR (600 MHz, CDCl3): δ = 7.57–7.54 (m, 2 H), 7.46–7.42 (m, 2 H), 7.38–7.34 (m, 2 H), 7.05 (dd, J = 7.8, 1.7 Hz, 1 H), 7.00 (dd, J = 12.0, 1.7 Hz, 1 H), 3.59 (dt, J = 10.2, 6.2 Hz, 1 H), 3.52 (dt, J = 10.2, 6.7 Hz, 1 H), 2.95 (h, J = 7.1 Hz, 1 H), 1.82 (dt, J = 7.1, 6.3 Hz, 2 H), 1.29 (d, J = 7.0 Hz, 3 H), 0.90 (s, 9 H), 0.03 (d, J = 1.5 Hz, 6 H) ppm. 13C NMR (150 MHz, CDCl3): δ =159.9 (d, J = 247.4 Hz), 149.3 (d, J = 6.7 Hz), 136.1, 130.6, 129.1, 128.5, 127.5, 126.5 (d, J = 13.4 Hz), 123.3, 114.7 (d, J = 22.6 Hz), 61.1, 41.1, 35.9, 26.1, 22.2, 18.4, –5.2 ppm. FTIR (ATR): 2956, 2928, 2856, 1484, 1472, 1462, 1418, 1254, 1098, 1076, 1010, 980, 900, 870, 832, 810, 774, 766, 724, 696 cm–1. MS (EI, 70 eV): m/z (%) = 302 (22), 301 (100), 207 (22), 179 (77), 165 (35). HRMS (EI, 70 eV): m/z calcd for [C21H28FOSi+]: 343.1888; found: 343.1872 [M+ – CH3].