8-Hydroxyquinolin-N-oxide-Promoted Copper-Catalyzed C–S Cross-Coupling of Thiols with Aryl Iodides

Abstract

8-Hydroxyquinolin-N-oxide was identified as a superior ligand for CuI-catalyzed C–S coupling reactions of aryl iodides with thiols to afford the corresponding thioethers in excellent yield. The method shows excellent chemoselectivity and high functional-group tolerance in both coupling partners.

Key words

C–S coupling reactions - copper - cross-coupling - 8-hydroxyquinolin-N-oxide - Ullmann reaction

• References and Notes

• 1a Hartwig JF. Angew. Chem. Int. Ed. 1998; 37: 2046
• 1b Beletskaya IP, Cheprakov AV. Coord. Chem. Rev. 2004; 248: 2337
• 1c Corbet JP, Mignani G. Chem. Rev. 2006; 106: 2651
• 1d Johannesson P, Lindeberg G, Johanson A, Nikiforovich GV, Gogoll A, Synnergren B, Le Greves M, Nyberg F, Karlen A, Hallberg A. J. Med. Chem. 2002; 45: 1767

For recent contributions on Pd-catalyzed C–S coupling reactions, see:
• 2a Fernández-Rodríguez MA, Shen Q, Hartwig JF. Chem.–Eur. J. 2006; 12: 7782
• 2b Fernández-Rodríguez MA, Shen Q, Hartwig JF. J. Am. Chem. Soc. 2006; 128: 2180

For recent contributions on Cu-catalyzed C–S coupling reactions, see:
• 3a Palomo C, Oiarbide M, Lopez R, Gomez-Bengoa E. Tetrahedron Lett. 2000; 41: 1283
• 3b Yee Kwong F, Buchwald SL. Org. Lett. 2002; 4: 3517
• 3c Bates CG, Gujadhur RK, Venkataraman D. Org. Lett. 2002; 4: 2803
• 3d Deng W, Zou Y, Wang YF, Liu L, Guo QX. Synlett 2004; 1254
• 3e Zhu D, Xu L, Wu F, Wan B. Tetrahedron Lett. 2006; 47: 5781
• 3f Chen Y.-J, Chen H.-H. Org. Lett. 2006; 8: 5609
• 3g Verma AK, Singh J, Chaudhary R. Tetrahedron Lett. 2007; 48: 7199
• 3h Carril M, SanMartin R, Dominguez E, Tellitu I. Chem.–Eur. J. 2007; 13: 5100
• 3i Lv X, Bao W. J. Org. Chem. 2007; 72: 3863
• 3j Xu H, Zhao X, Deng J, Fu Y, Feng Y. Tetrahedron Lett. 2009; 50: 434
• 3k Zhang H, Cao W, Ma D. Synth. Commun. 2007; 37: 25
• 3l Prasad DJ. C, Naidu AB, Sekar G. Tetrahedron Lett. 2009; 50: 1411
• 3m Feng Y, Wang H, Sun F, Li Y, Fu X, Jin K. Tetrahedron 2009; 65: 9737
• 3n Basu B, Mandal B, Das S, Kundu S. Tetrahedron Lett. 2009; 50: 5523

For recent contributions on Ni-catalyzed C–S coupling reactions, see:
• 4a Zhang Y, Ngeow KN, Ying JY. Org. Lett. 2007; 9: 3495
• 4b Jammi S, Barua P, Rout L, Saha P, Punniyamurthy T. Tetrahedron Lett. 2008; 49: 1484
• 5 For recent contributions on Co-catalyzed C–S coupling reactions, see: Wong YC, Jayanth TT, Cheng CH. Org. Lett. 2006; 8: 5613

For recent contributions on Fe-catalyzed C–S coupling reactions, see:
• 6a Correa A, Carril M, Bolm C. Angew. Chem. Int. Ed. 2008; 47: 2880
• 6b Wu WY, Wang JC, Tsai FY. Green. Chem. 2009; 11: 326

For recent contributions on In-catalyzed C–S coupling reactions, see:
• 7a Reddy VP, Swapna K, Kumar AV, Rao KR. J. Org. Chem. 2009; 74: 3189
• 7b Reddy VP, Kumar AV, Swapna K, Rao KR. Org. Lett. 2009; 11: 1697
• 8a Yang K, Qiu Y, Li Z, Wang Z, Jiang S. J. Org. Chem. 2011; 76: 3151
• 8b Yang K, Li Z, Wang Z, Yao Z, Jiang S. Org. Lett. 2011; 13: 4340
• 8c Qiu Y, Liu Y, Yang K, Hong W, Li Z, Wang Z, Yao Z, Jiang S. Org. Lett. 2011; 13: 3556
• 8d Zeng X, Huang W, Qiu Y, Jiang S. Org. Biomol. Chem. 2011; 9: 8224
• 9 General Experimental Procedure An argon-filled flask was charged with CuI (20 mg, 0.1 mmol, 10 mol%), L5 (32 mg, 0.2 mmol, 20 mol%), Cs₂CO₃ (652 mg, 2 mmol, and thiophenol (1 mmol). The aryl iodide (1.5 mmol) and DMSO (1 mL) were injected into the flask under argon atmosphere. The contents were then stirred at 80 °C for 24 h. After allowing the mixture to cool to r.t., the mixture was diluted with EtOAc (20 mL) and filtered. The filtrate was washed with H₂O (2 × 10 mL). The organic phase was dried with Na₂SO₄, filtered, and the solvent was removed under vacuum, and the residue was purified by chromatography on silica gel to give the desired aryl sulfide. Spectroscopic Data of the Representative Compounds: (2,4,6-Trimethylphenyl)phenyl Sulfide (3c) ¹HNMR (400 MHz, CDCl₃): δ = 7.19–7.15 (t, J = 7.60 Hz, 2 H), 7.07–7.01 (m, 3 H), 6.93–6.91 (d, J = 7.60 Hz, 2 H), 2.39 (s, 6 H), 2.32 (s, 3 H). ¹³C NMR (125 MHz, CDCl₃): δ = 143.7, 139.2, 138.4, 129.3, 128.8, 126.9, 125.5, 124.4, 21.7, 21.1. 3-Pyridyl Phenyl Sulfide (3m) ¹HNMR (400 MHz, CDCl₃): δ = 8.56–8.55 (s, 1 H), 8.46–8.45 (q, J = 4.8 Hz, 1 H), 7.60–7.58 (d, J = 8.00 Hz, 1 H), 7.39–7.29 (m, 5 H), 7.22–7.19 (q, J = 4.80 Hz, 1 H). ¹³C NMR (125 MHz, CDCl₃): δ = 151.1, 147.8, 137.9, 133.9, 133.6, 131.7, 129.5, 127.8, 123.9. 2-(4-Tolylsulfanyl)phenyl Bromide (3o) ¹HNMR (400 MHz, CDCl₃): δ = 7.54–7.52 (d, J = 7.6 Hz, 1 H), 7.40–7.38 (d, J = 8.00 Hz, 2 H), 7.23–7.21 (d, J = 8.00 Hz, 1 H), 7.13–7.08 (m, 1 H), 7.00–6.96 (m, 1 H), 6.82–6.79 (dd, J = 7.60 Hz, 1 H), 2.38 (s, 3 H). ¹³C NMR (125 MHz, CDCl₃): δ = 139.8, 139.0, 134.4, 132.9, 130.5, 128.7, 128.7, 127.7, 126.6, 122.0, 21.3.