Synlett 2009(12): 1990-1996  
DOI: 10.1055/s-0029-1217517
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Gold(III) Bromide Catalyzed Furannulation of 2-Alkynylcycloalk-2-enols: An Expedient Route to Fused Furans

C. Praveen, P. Kiruthiga, P. T. Perumal*
Organic Chemistry Division, Central Leather Research Institute, Adyar, Chennai 600020, India
Fax: +91(44)24911589; e-Mail: ptperumal@gmail.com;
Further Information

Publication History

Received 15 February 2009
Publication Date:
25 June 2009 (online)

Abstract

An efficient synthesis of fused furans from 2-alkynyl­cycloalk-2-enols via gold(III) bromide catalyzed cycloisomerization was achieved. The reaction condition is moderate and amenable to structurally diverse substrates, leading to good yield of products.

    References and Notes

  • 1a Ho T.-L. Lee K.-Y. Tetrahedron Lett.  1995,  36:  947 
  • 1b Li X. Kyne RE. Ovaska TV. Tetrahedron  2007,  63:  1899 
  • 1c Maddaford SP. Andersen NG. Cristofoli WA. Keay BA. J. Am. Chem. Soc.  1996,  118:  10766 
  • 1d Patre RE. Gawas S. Sen S. Parameswaran PS. Tilve SG. Tetrahedron Lett.  2007,  48:  3517 
  • 1e Gasper H. Santos S. Carbone M. Rodrigues AS. Rodrigues AI. Uriz MJ. Feio SMS. Melck D. Humanes M. Gavagnin M. J. Nat. Prod.  2008,  71:  2049 
  • 1f Tori M. Okamoto Y. Tachikawa K. Mihara K. Watanabe A. Sakaoku M. Takaoka S. Tanaka M. Gong X. Kuroda C. Hattori M. Hanai R. Tetrahedron  2008,  64:  9136 
  • 1g Cambie RC. Rutledge PS. Yang X.-S. Bergquist PR. J. Nat. Prod.  1998,  61:  1416 
  • 1h Chakraborty A. Kar GK. Ray JK. Tetrahedron  1997,  53:  2989 
  • 1i Gavagnin M. Mollo E. Castelluccio F. Crispino A. Cimino G. J. Nat. Prod.  2003,  66:  1517 
  • 1j Hikino H. Hikino Y. Yosioka I. Chem. Pharm. Bull.  1964,  12:  755 
  • 1k Dixit M. Sharon A. Maulik PR. Goel A. Synlett  2006,  1497 
  • 2a Iguchi K. Mori K. Suzuki M. Takahashi H. Yamada Y. Chem. Lett.  1986,  1789 
  • 2b Blay G. Cardona L. Garcia B. Pedro JR. Sanchez JJ. J. Org. Chem.  1996,  61:  3815 
  • 3a Cimino C. De Stafano S. Guerriero A. Minale L. Tetrahedron Lett.  1975,  16:  1425 
  • 3b Allen AJ. Vaillancourt V. Albizati KF. Org. Prep. Proced. Int.  1994,  26:  1 
  • 3c Foot JS. Phillis AT. Sharp PP. Willis A. Banwell MG. Tetrahedron Lett.  2008,  47:  6817 
  • 4a Inou M. Frontier AJ. Danishefsky SJ. Angew. Chem. Int. Ed.  2000,  39:  761 
  • 4b Kerr DJ. Willis AC. Flynn BL. Org. Lett.  2004,  6:  457 
  • 4c Patil AD. Freyer AJ. Killmer L. Offen P. Carte B. Jurewicz AJ. Johnson RK. Tetrahedron  1997,  53:  5047 
  • 4d Hallock YF. Cardellina JH. Boyd MR. Nat. Prod. Lett.  1998,  11:  153 
  • 5a Yim H.-K. Liao Y. Wong HNC. Tetrahedron  2003,  59:  1877 
  • 5b Inouye H. Matsumara H. Kawasaski M. Inoue K. Tsukada M. Tabata M. Phytochemistry  1981,  20:  1701 
  • 5c Tanaka J. Miki H. Higa T. J. Nat. Prod.  1992,  55:  1522 
  • 6a Yoshida M. Al-Amin M. Matsuda C. Baati R. Tetrahedron Lett.  2008,  49:  5021 
  • 6b Yao T. Zhang X. Larock RC. J. Am. Chem. Soc.  2004,  126:  11164 
  • 6c Oh CH. Reddy VR. Kim A. Rhim CY. Tetrahedron Lett.  2006,  47:  5307 
  • 6d Patil NT. Wu H. Yamamoto Y.
    J. Org. Chem.  2005,  70:  4531 
  • 6e Hashmi ASK. Schwarz L. Choi J.-H. Frost TM. Angew. Chem. Int. Ed.  2000,  39:  2285 
  • 6f Zhang J. Schmalz H.-G. Angew. Chem. Int. Ed.  2006,  45:  6704 
  • 6g Goncalves S. Wagner A. Mioskowski C. Baati R. Tetrahedron Lett.  2009,  50:  274 
  • 7a Mehta G. Likhite NS. Tetrahedron Lett.  2008,  49:  7113 
  • 7b Harada K. Tonoi Y. Kato H. Fukuyama Y. Tetrahedron Lett.  2002,  43:  3829 
  • 7c Foot JS. Phillis AT. Sharp PP. Wills AC. Banwell MG. Tetrahedron Lett.  2006,  47:  6817 
  • 8a Patil NT. Yamamoto Y. Chem. Rev.  2008,  108:  3395 
  • 8b Hoffmann-Röder A. Krause N. Org. Biomol. Chem.  2005,  3:  387 
  • 8c Hashmi ASK. Angew. Chem. Int. Ed.  2005,  44:  6990 ; Angew. Chem. 2005, 117, 7150
  • 8d Arcadi A. Giuseppe SD. Curr. Org. Chem.  2004,  8:  795 
  • 8e Gorin DJ. Toste D. Nature (London)  2007,  446:  395 
  • 8f Widenhoefer RA. Han X. Eur. J. Org. Chem.  2006,  4555 
  • 8g Ferrer C. Amijis CHM. Echavarren AM. Chem. Eur. J.  2007,  13:  1358 
  • 8h Fürstner A. Davies PW. Angew. Chem. Int. Ed.  2006,  46:  3410 
  • 8i Hashmi ASK. Chem. Rev.  2007,  107:  3180 
  • 8j Nunez EJ. Echavarren AM. Chem. Commun.  2007,  333 
  • 8k Hashmi ASK. Hutchings GJ. Angew. Chem. Int. Ed.  2006,  45:  7896 
  • 8l Widehhoefer RA. Han X. Eur. J. Org. Chem.  2006,  4555 
  • 8m Shen HC. Tetrahedron  2008,  64:  7847 
  • 8n Shen HC. Tetrahedron  2008,  64:  3885 
  • 8o Li Z. Brouwer C. He C. Chem. Rev.  2008,  108:  3239 
  • 9a Belting V. Krause N. Org. Lett.  2006,  8:  4489 
  • 9b Liu B. De Brabander JK. Org. Lett.  2006,  8:  4907 
  • 9c Belting V. Krause N. Org. Biomol. Chem.  2009,  7:  1221 
  • 9d Harkat H. Weibel J.-M. Pale P. Tetrahedron Lett.  2007,  48:  1439 
  • 9e Buzas A. Istrate F. Gagosz F. Org. Lett.  2006,  8:  1957 
  • 9f Jung HH. Floreancig PE. Org. Lett.  2006,  8:  1949 
  • 9g Liu Y. Song F. Song Z. Liu M. Yan B. Org. Lett.  2005,  7:  5409 
  • 9h Kirsch SF. Binder JT. Liebert C. Menz H. Angew. Chem.  2006,  118:  6010 
  • 9i Hashmi ASK. Schwarz L. Choi J.-H. Frost TM. Angew. Chem.  2000,  112:  2382 
  • 9j Antoniotti S. Genin E. Michelet V. Genêt J.-P. J. Am. Chem. Soc.  2005,  127:  9976 
  • 9k Barluenga J. Dieguez A. Fernandez A. Rodriguez F. Fananas FJ. Angew. Chem.  2006,  118:  1 
  • 9l Kirsch SF. Binder JT. Liebert C. Menz H. Angew. Chem. Int. Ed.  2006,  45:  6704 
  • 9m Hashmi ASK. Schwarz L. Choi J.-H. Frost TM. Angew. Chem. Int. Ed.  2000,  39:  2285 
  • 9n Barluenga J. Dieguez A. Fernandez A. Rodriguez F. Fananas FJ. Angew. Chem. Int. Ed.  2006,  45:  2091 
  • 10 Praveen C. Sagayaraj YW. Perumal PT. Tetrahedron Lett.  2009,  50:  644 
  • 11 Marshall JA. Sehon CA. J. Org. Chem.  1995,  60:  5966 
  • 12 Qing F.-L. Gao W.-Z. Ying J. J. Org. Chem.  2000,  65:  2003 
  • 13a Sonogashira K. In Metal-Catalyzed Cross-Coupling Reactions   Diederich F. Stang PJ. Wiley-VCH; Weinheim: 1998.  Chap. 5. p.203-229  
  • 13b Sonogashira K. Tohda Y. Hagihara N. Tetrahedron Lett.  1975,  16:  4467 
14

General Procedure for the Synthesis of 2-Alkynyl­cyclo-alk-2-enol 3a-l Representative Procedure for 2-(Phenylethynyl)cyclohex-2-enol (3f, Table 1, Entry 6)
2-Iodocyclohex-2-enol (1b, 1.0 mmol), Pd(PPh3)Cl2 (5 mol%), and CuI (5 mol%) were placed in an oven-dried flask under N2. Dry Et3N was added, and the resulting suspension was magnetically stirred. Upon dropwise addition of phenylacetylene 2a (1.2 mmol), the mixture was stirred at r.t. until TLC showed the disappearance of the starting 2-iodo-cyclohex-2-enol (ca. 6 h). H2O (50 mL) was added to the reaction mixture, and the residue was extracted into EtOAc (4 × 15 mL), and the extract was dried over anhyd Na2SO4. Removal of the solvent under reduced pressure gave the crude product, which was further purified by column chromatography on silica gel using EtOAc-PE (1:9) as eluent to afford pure product 3f (91%) as a brown oil. IR (CH2Cl2): 3383, 2928, 1592, 1053, 755 cm. ¹H NMR (500 MHz, CDCl3): δ = 1.60-1.62 (m, 1 H), 1.75-1.78 (m, 3 H), 1.87-1.90 (m, 1 H), 2.12-2.21 (m, 2 H), 4.26 (br s, 1 H), 6.30 (t, J = 4.6 Hz, 1 H), 7.28-7.29 (m, 3 H), 7.43-7.44 (m, 2 H). ¹³C NMR (125 MHz, CDCl3): δ = 18.1, 26.0, 30.6, 66.9, 88.4, 89.3, 123.2, 124.2, 128.2, 128.3, 131.6, 137.8. MS (EI): m/z = 198 [M+]. Anal. Calcd for C14H14O: C, 84.81; H, 7.12. Found: C, 84.91; H, 7.09.

15

General Procedure for the Synthesis of Fused Furans 4a-lRepresentative Procedure for 2-Phenyl-4,5,6,7-tetrahydrobenzofuran (4f, Table 3, Entry 6)
To a soln of 2-(phenylethynyl)cyclohex-2-enol (3f, 1.0 mmol) in DCE (1 mL) under N2 was added AuBr3 (5 mol%) and heated the reaction mixture at 70 ˚C for 30 min. After completion of the reaction as indicated by TLC, the reaction mixture was concentrated under reduced pressure and purified by column chromatography over silica gel (100-200 mesh) to afford pure product 4f (86%) as a colourless liquid. R f  = 0.82 (EtOAc-PE, 1:9). IR (CH2Cl2): 2934, 2815, 2354, 1669, 1600, 1247, 760 cm. ¹H NMR (500 MHz, CDCl3): δ = 1.75-1.78 (m, 2 H), 1.84-1.89 (m, 2 H), 2.46 (t, J = 6.1 Hz, 2 H), 6.47 (s, 1 H), 7.20 (t, J = 7.6 Hz, 1 H), 7.35 (t, J = 7.6 Hz, 2 H), 7.62 (d, J = 6.9 Hz, 2 H). ¹³C NMR (125 MHz, CDCl3): δ = 22.2, 23.1, 23.2, 23.4, 106.1, 119.0, 123.3, 126.6, 128.6, 131.5, 150.9. MS (EI): m/z = 221 [M+ + Na+]. Anal. Calcd for C14H14O: C, 84.81; H, 7.12. Found: C, 84.75; H, 7.15.