F
H. Sterckx et al.
Cluster
Synlett
(IWT-Flanders), the University of Antwerp (BOF) and the Hercules
Foundation.
(10) For the synthesis of (aryl)azinylmethanes, see: (a) De Houwer,
J.; Maes, B. U. W. Synthesis 2014, 46, 2533. (b) Lima, F.;
Kabeshov, M. A.; Tran, D. N.; Battilocchio, C.; Sedelmeier, J.;
Sedelmeier, G.; Schenkel, B.; Ley, S. V. Angew. Chem. Int. Ed.
2016, 55, 14085.
Supporting Information
(11) (a) Friis, S. D.; Pirnot, M. T.; Buchwald, S. L. J. Am. Chem. Soc.
2016, 138, 8372. (b) Llaveria, J.; Leonori, D.; Aggarwal, V. K.
J. Am. Chem. Soc. 2015, 137, 10958. (c) Li, Y.; Deng, G.; Zeng, X.
Organometallics 2016, 35, 747. (d) Andou, T.; Saga, Y.; Komai,
H.; Matsunaga, S.; Kanai, M. Angew. Chem. Int. Ed. 2013, 52,
3213.
Supporting information for this article is available online at
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References and Notes
(12) pKa values were calculated using Advanced Chemistry Develop-
ment (ACD/Labs) Software V11.02 (© 1994–2017 ACD/Labs)
and were extracted from SciFinder®.
(13) Kleemann, A.; Engel, J.; Kutscher, B.; Reichert, D. Pharmaceutical
Substances, 4th ed.; Thieme: Stuttgart, 2001.
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J. Am. Chem. Soc. 2000, 122, 4280.
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(1) For reviews and concepts dealing with base metal catalyzed
oxidations using oxygen as the terminal oxidant, see: (a) Hone,
C. A.; Roberge, D. M.; Kappe, C. O. ChemSusChem 2017, 10, 32.
(b) Allen, S. E.; Walvoord, R. R.; Padilla-Salinas, R.; Kozlowski, M.
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Hellgardt, K.; Hii, K. K.; Hutchings, G. J.; Brett, G. L.; Kuhn, S.;
Marsden, S. P. React. Chem. Eng. 2016, 1, 595.
(2) Anastas, P.; Eghbali, N. Chem. Soc. Rev. 2010, 39, 301.
(3) For some examples of mechanistic studies, see: (a) Sterckx, H.;
De Houwer, J.; Mensch, C.; Caretti, I.; Tehrani, K. A.; Herrebout,
W. A.; Van Doorslaer, S.; Maes, B. U. W. Chem. Sci. 2016, 7, 346.
(b) Hoover, J. M.; Ryland, B. L.; Stahl, S. S. J. Am. Chem. Soc. 2013,
135, 2357. (c) Hoover, J. M.; Ryland, B. L.; Stahl, S. S. ACS Catal.
2013, 3, 2599. (d) ten Brink, G.-J.; Arends, I. W. C. E.; Sheldon, R.
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L.; Wiener, H.; Sasson, Y. J. Chem. Soc., Perkin Trans. 2 1998,
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(4) For some examples, see: (a) Hruszkewycz, D. P.; Miles, K. C.;
Thiel, O. R.; Stahl, S. S. Chem. Sci. 2017, 8, 1282. (b) Abe, T.;
Tanaka, S.; Ogawa, A.; Tamura, M.; Sato, K.; Itoh, S. Chem. Lett.
2017, 46, 348.
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Chem. Int. Ed. 2012, 51, 2745. (b) Sterckx, H.; De Houwer, J.;
Mensch, C.; Herrebout, W.; Tehrani, K. A.; Maes, B. U. W. Beil-
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(16) Typical Procedure for Fe-Catalyzed Aerobic C–H Oxygenation
of 1a
A 10 mL vial was charged with FeCl2·4H2O (9.94 mg, 0.050
mmol), 2-(1-phenylethyl)pyridine (1a) (0.092 g, 0.5 mmol), sal-
icylic acid (0.069 g, 0.500 mmol), and DMSO (1 mL). The vial
was flushed for 10 s with O2, capped with an aluminum crimp
cap with septum and stirred at 100 °C for 24 h with an O2
balloon through the septum. After cooling down to r.t., the
content of the vial was transferred into a separation funnel and
the vial was rinsed with CH2Cl2 (20 mL). Aqueous sat. NaHCO3
(10 mL) was added, and the organic phase was separated. The
aqueous phase was extracted twice with CH2Cl2 (10 mL). The
combined organic fractions were washed with brine (20 mL),
dried on MgSO4, and filtered. Further purification was achieved
by automated column chromatography (heptane–EtOAc) to give
1-phenyl-1-(pyridin-2-yl)ethanol (2a) in 88% yield.
Characterization Data for 2a
Colorless oil. ESI–HRMS: m/z calcd for C13H14NO [M + H]+:
200.1070; found: 200.1080. 1H NMR (400 MHz, CDCl3): δ = 8.51
(d, 1 H, J = 4.6 Hz), 7.62 (dt, 1 H, J = 7.8, 1.4 Hz), 7.47 (d, 2 H, J =
7.4 Hz), 7.34–7.25 (m, 3 H), 7.25–7.11 (m, 2 H), 5.80 (s, 1 H),
1.92 (s, 3 H). 13C NMR (100 MHz, CDCl3): δ = 164.8 (C], 147.4
(CH), 147.2 (C), 136.9 (CH), 128.2 (CH), 127.0 (CH), 125.9 (CH),
122.0 (CH), 120.3 (CH), 75.1 (C), 29.3 (CH3).
Characterization Data for 2m
Colorless viscous oil. ESI–HRMS: m/z calcd for C22H20NO5 [M +
H]+: 378.1336; found: 378.1342. 1H NMR (400 MHz, CDCl3): δ =
8.58 (d, 1 H, J = 4.5 Hz), 7.65 (dt, 1 H, J = 7.7, 1.3 Hz), 7.29 (d, 4 H,
J = 8.6 Hz), 7.26–7.21 (m, 1 H), 7.12 (d, 1 H, J = 7.9 Hz), 7.02 (d, 4
H, J = 8.6 Hz), 6.29 (br s, 1 H), 2.28 (s, 6 H). 13C NMR (100 MHz,
CDCl3): δ = 169.3 (C), 162.7 (C), 150.0 (C), 147.8 (CH), 143.4 (C),
136.6 (CH), 129.3 (CH), 122.9 (CH), 122.6 (CH), 121.0 (CH), 80.2
(C), 21.2 (CH3).
© Georg Thieme Verlag Stuttgart · New York — Synlett 2017, 28, A–F