Palladium-Catalyzed Synthesis of Aryl Amides through Silanoate-Mediated Hydrolysis of Nitriles

Dedicated to Professor Steven V. Ley on the occasion of his 70^th birthday

Abstract

A procedure for the formation of aryl amides through the palladium-catalyzed coupling of nitriles and aryl bromides, via the formation of intermediary silanoate derived imidate species is reported. Optimization was undertaken and examples of the process are described that furnish the products in up to 86% isolated yield.

Key words

amidation - palladium - catalysis - nitriles - hydrolysis

• References and Notes

• 1 Sewald N, Jakubke HD. Peptides: Chemistry and Biology, 2nd ed. . Wiley-VCH; Weinheim: 2009
• 2 Biraman VR, Bode JW. Nature 2011; 480: 471
• 3 Roughley SD, Jordan AM. J. Med. Chem. 2011; 54: 3451
• 4 El-Faham A, Albericio F. Chem. Rev. 2011; 111: 6557
• 5 Valeur E, Bradley M. Chem. Soc. Rev. 2009; 38: 606
• 6 Montalbetti CA. G. N, Falque V. Tetrahedron 2005; 61: 10827
• 7 For a review, see: Lanigan RM, Sheppard TD. Eur. J. Org. Chem. 2013; 7453
• 8 Arnold K, Batsanov AS, Davies B, Whiting A. Green Chem. 2008; 10: 124
• 9 Allen CL, Chhatwal AR, Williams JM. J. Chem. Commun. 2012; 48: 666
• 10 Gernigon N, Al-Zoubi RM, Hall DG. J. Org. Chem. 2012; 77: 8386
• 11 Ohshima T, Hayashi Y, Agura K, Fujii Y, Yoshiyama A, Mashima K. Chem. Commun. 2012; 48: 5434
• 12 Lenstra DC, Rutjes FP. T. J, Mecinovic J. Chem. Commun. 2014; 50: 5763
• 13a Caldwell N, Jamieson C, Simpson I, Tuttle T. Org. Lett. 2013; 15: 2506
• 13b Caldwell N, Jamieson C, Simpson I, Watson AJ. B. ACS Sustain. Chem. Eng. 2013; 1: 1339
• 13c Caldwell N, Campbell PS, Jamieson C, Potjewyd F, Simpson I, Watson AJ. B. J. Org. Chem. 2014; 79: 9347
• 13d Caldwell N, Jamieson C, Simpson I, Watson AJ. B. Chem. Commun. 2015; 51: 9495
• 14 Merchant KJ. Tetrahedron Lett. 2000; 41: 3747
• 15 Huang X, Buchwald SL. Org. Lett. 2001; 3: 3417
• 16 Klapars A, Huang X, Buchwald SL. J. Am. Chem. Soc. 2002; 124: 7421
• 17 Surry DS, Buchwald SL. Chem. Sci. 2011; 2: 27
• 18 Full details are reported in the Supporting Information.
• 19 Carlson R, Carlson JE. Design and Optimization in Organic Synthesis, 2nd ed. . Elsevier; Amsterdam: 2005
• 20 Stat-Ease Design Expert v8; http://www.statease.com/.
• 21 N-(6-Nitropyridin-3-yl)benzamide (10); Typical Procedure: To an oven-dried Radley’s reaction tube containing potassium {phenyl[(trimethylsilyl)oxy]methylene}amide (2; 200 mg, 0.86 mmol, 1 equiv) was added 20 mol% Pd₂(dba)₃ (158.2 mg, 0.16 mmol, 0.2 equiv) and 20 mol% XPhos (82.3 mg, 0.16 mmol, 0.2 equiv). The reaction tube was then purged and 1,4-dioxane (8.6 mL) was added. The reaction mixture was then heated at 100 °C for 10 min. 5-Bromo-2-nitropyridine (140 mg, 0.69 mmol, 0.8 equiv) was then added, the reaction tube was purged, and the reaction mixture was then heated at 100 °C for 16 h. The reaction mixture was taken up in EtOAc (30 mL) and washed with brine (3 × 30 mL). The organics were extracted, dried, and concentrated to a residue, which was purified by flash column chromatography [EtOAc–petroleum ether (40–60 °C), 30%] to afford the title compound (135.4 mg, 81%) as an orange–brown solid. IR (neat): 3319, 1683, 1612, 1519, 1495, 1346, 703, 770 cm^–1; ¹H NMR (500 MHz, DMSO-d ₆): δ = 11.02 (s, 1 H), 9.00 (d, J = 2.5 Hz, 1 H), 8.62 (dd, J = 8.9, 2.5 Hz, 1 H), 8.40 (d, J = 8.9 Hz, 1 H), 8.02–8.01 (m, 2 H), 7.66 (t, J = 7.4 Hz, 1 H), 7.59 (t, J = 7.6 Hz, 2 H); ¹³C NMR (126 MHz, DMSO-d ₆): δ = 166.4, 151.3, 141.3, 139.6, 133.7, 132.5, 129.1, 128.6, 128.0, 119.3; HRMS: m/z [M + H⁺] calcd for C₁₂H₁₀N₃O₃: 244.0717; found: 244.0714.
• 22 Tamararu Y, Yamada Y, Inoue K, Yamamoto Y, Yoshida Z. J. Org. Chem. 1983; 48: 1286
• 23 Baker JW, Bachman GL, Schumacher I, Roman DP, Tharp AL. J. Med. Chem. 1967; 10: 93
• 24a Chan DM. T, Monaco KL, Wang RP, Winters MP. Tetrahedron Lett. 1998; 39: 2933
• 24b Evans DA, Katz JL, West TR. Tetrahedron Lett. 1998; 39: 2937
• 24c Lam PY. S, Clark CG, Saubern S, Adams J, Winters MP, Chan DT, Combs A. Tetrahedron Lett. 1998; 39: 2941
• 25a Tsuji J, Takahashi H, Morikawa M. Tetrahedron Lett. 1965; 4387
• 25b Trost BM, VanVranken DL. Chem. Rev. 1996; 96: 395
• 25c Tsuji J, Minami I. Acc. Chem. Res. 1987; 20: 140