Synlett 2003(5): 0708-0710
DOI: 10.1055/s-2003-38357
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

First Thermal and Transition Metal Catalysed Intramolecular [4+2] Cycloaddition Reactions with N-Tethered Ynamides

Bernhard Witulski*, Jan Lumtscher, Uwe Bergsträßer
Fachbereich Chemie, Universität Kaiserslautern, Erwin-Schrödinger-Straße, 67663 Kaiserslautern, Germany
Fax: +49(631)2053921; e-Mail: witulski@rhrk.uni-kl.de;
Further Information

Publication History

Received 6 January 2003
Publication Date:
28 March 2003 (online)

Abstract

Cationic rhodium(I)-complexes generated from [RhCl(PPh3)3] and AgSbF6 catalyse at room temperature the first examples of intramolecular [4+2] cycloaddition reactions with N-tethered ynamides and provide an efficient access to synthetically versatile tetrahydroindoles.

    References

  • 1a Corey EJ. Angew. Chem. Int. Ed.  2002,  41:  1650 
  • 1b Nicolaou KC. Snyder SA. Montagnon T. Vassilikogiannakis GE. Angew. Chem. Int. Ed.  2002,  41:  1701 
  • 1c Fringuelli F. Taticchi A. The Diels-Alder Reaction   Wiley and Sons; Chichester: 2002. 
  • 2a Fearnley SP. Market E. Chem. Commun.  2002,  438 
  • 2b Padwa A. Bur SK. Danca DM. Ginn JD. Lynch SM. Synlett  2002,  851 
  • 2c Oppolzer W. Flaskamp E. Bieber LW. Helv. Chim. Acta  2001,  84:  141 
  • 2d Boger DL. Wolkenberg SE. J. Org. Chem.  2000,  65:  9120 
  • 2e Magnus P. Cairns PM. J. Am. Chem. Soc.  1986,  108:  217 
  • 2f Martin SF. Tu C. Kimura M. Simonsen SH. J. Org. Chem.  1982,  47:  3634 
  • 2g Stork G. Morgans DJ. J. Am. Chem. Soc.  1979,  101:  7110 
  • 3a Genet JP. Ficini J. Tetrahedron Lett.  1979,  1499 
  • 3b Iwamoto K. Fukuta H. Suzuki S. Maruyama J. Oishi E. Miyashita A. Higashino T. Heterocycles  1996,  43:  2409 
  • 3c Barluenga J. Ferrero M. Peláez-Arango E. López-Ortiz F. Palacios F. J. Chem. Soc., Chem. Commun.  1994,  865 
  • 3d Padwa A. Gareau Y. Harrison B. Rodriguez A. J. Org. Chem.  1992,  57:  3540 
  • 3e Boger DL. Dang Q. Tetrahedron  1988,  44:  3379 
  • 3f Himbert G. Brunn W. Liebigs Ann. Chem.  1986,  1067 
  • 3g For Hetero Diels-Alder reactions with ynamines, see: van Elburg PA. Honig GWN. Reinhout DN. Tetrahedron Lett.  1987,  28:  6397 
  • 3h See also: Vilsmaier E. Baumheier R. Chem. Ber.  1989,  122:  1285 
  • 4 Witulski B. Stengel T. Angew. Chem. Int. Ed.  1998,  37:  498 
  • 5a Witulski B. Alayrac C. Angew. Chem. Int. Ed.  2002,  41:  3281 
  • 5b Witulski B. Stengel T. Fernández-Hernández JM. Chem. Commun.  2000,  1965 
  • 5c Witulski B. Buschmann N. Bergsträßer U. Tetrahedron  2000,  56:  8473 
  • 5d Witulski B. Gößmann M. Synlett  2000,  1793 
  • 5e Witulski B. Stengel T. Angew. Chem. Int. Ed.  1999,  38:  2426 
  • 5f Witulski B. Gößmann M. Chem. Commun.  1999,  1879 
  • 5g For other contributions to the chemistry of ynamides, see: Hoffmann RW. Brückner D. New J. Chem.  2001,  25:  369 
  • 5h Rainier JD. Imbriglio JE. J. Org. Chem.  2000,  65:  7272 
  • 5i Mulder JA. Hsung RP. Frederick MO. Tracey MR. Zificsak CA. Org. Lett.  2002,  4:  1383 
  • 5j Wei L.-L. Mulder JA. Xiong H. Zificsak CA. Douglas CJ. Hsung RP. Tetrahedron  2001,  57:  459 
  • 5k Saito N. Sato Y. Mori M. Org. Lett.  2002,  4:  809 
  • 6a Kitamura T. Kotani M. Yokoyama T. Fujiwara Y. Hori K. J. Org. Chem.  1999,  64:  680 
  • 6b Murch P. Arif AM. Stang PJ. J. Org. Chem.  1997,  62:  5959 
  • 6c Zhdankin VV. Stang PJ. Chem. Rev.  2002,  102:  2523 
  • 7 Feldman KS. Mareska DA. J. Am. Chem. Soc.  1998,  120:  4027 
  • Nickel(0)-catalysed intramolecular [4+2] cycloaddition reactions:
  • 9a Wender PA. Jenkins TE. J. Am. Chem. Soc.  1989,  111:  6432 
  • 9b Wender PA. Smith TE. J. Org. Chem.  1996,  61:  824 
  • 9c Wender PA. Smith TE. Tetrahedron  1998,  54:  1255 
  • 9d DiMauro EF. Kozlowski MC. J. Chem. Soc., Perkin Trans. 1  2002,  439 
  • Rhodium(I)- and cationic rhodium(I)-catalysed intramolecular [4+2] cycloaddition reactions:
  • 10a Jolly RS. Luedtke G. Sheehan D. Livinghouse T. J. Am. Chem. Soc.  1990,  112:  4965 
  • 10b Wender PA. Jenkins TE. Suzuki S. J. Am. Chem. Soc.  1995,  117:  1843 
  • 10c McKinstry L. Livinghouse T. Tetrahedron  1994,  50:  6145 
  • 10d O’Mahony DJR. Belanger DB. Livinghouse T. Synlett  1998,  443 
  • 10e Gilbertson SR. Hoge GS. Genov DG. J. Org. Chem.  1998,  63:  10077 
  • 10f Paik S.-J. Son SU. Chung YK. Org. Lett.  1999,  1:  2045 
8

Spectral data for dienyne 7: 1H NMR (400 MHz, CDCl3): δ = 7.80 (m, 2 H), 7.35 (m, 2 H), 6.23 (m, 1 H), 6.07 (m, 1 H), 5.55 (m, 1 H), 5.11 (d, J = 16.1 Hz, 1 H), 5.01 (d, J = 9.1 Hz, 1 H), 3.38 (m, 2 H), 2.78 (s, 1 H), 2.43 (s, 3 H), 2.39 (m, 2 H). 13C NMR (100 MHz, CDCl3): δ = 144.7, 136.6, 133.8, 130.0, 129.8, 127.6, 134.6, 116.3, 75.8, 59.5, 50.6, 30.9, 21.6.

11

Experimental Procedure: [RhCl(PPh3)3] (9.3 mg, 0.01 mmol) was added to a solution of ynamide 4-8 (0.20 mmol) in dry toluene (10 mL) under argon. After stirring for 5 min at r.t., AgSbF6 (0.01 mmol, 0.2 mL of a 0.05 M solution in 1,2-dichloroethane) was added and the reaction mixture was stirred at r.t. The reaction mixture was filtered through a small plug of celite, the solvent was evaporated and the resulting crude product was purified by column chromatography (Al2O3 III/N, hexanes-EtOAc = 8:2) to afford 9, 11-14.
Compound 9: Mp 87-88 °C. 1H NMR (400 MHz, CDCl3): δ = 7.72 (d, J = 8.4 Hz, 2 H), 7.28 (d, J = 8.4 Hz, 2 H), 5.76 (m, 2 H), 5.66 (m, 1 H), 3.76 (m, 1 H), 3.33 (m, 1 H), 2.77 (m, 2 H), 2.54 (m, 1 H), 2.41 (s, 3 H), 2.02 (m, 1 H), 1.49 (m, 1 H). 13C NMR (100 MHz, CDCl3): δ = 143.6, 137.9, 134.8, 129.5, 127.2, 126.5, 125.3, 103.1, 48.9, 38.0, 28.7, 26.9, 21.5. MS (EI, 70 eV): m/z (%) = 275 (43) [M+], 91 (100). Anal. Calcd for C15H17NO2S: C, 65.43; H, 6.22; N, 5.09. Found: C, 65.15; H, 6.06; N, 5.31. Compound 11: Mp 74-75 °C. 1H NMR (400 MHz, CDCl3): δ = 7.70 (d, J = 8.3 Hz, 2 H), 7.27 (d, J = 8.3 Hz, 2 H), 5.79 (m, 1 H), 5.64 (m, 1 H), 3.46 (m, 2 H), 2.96-2.81 (m, 2 H), 2.47 (s, 3 H), 1.89 (m, 2 H), 1.34 (m, 1 H), 0.35 (s, 9 H). 13C NMR (100 MHz, CDCl3): δ = 145.2, 143.6, 134.8, 129.5, 128.1, 125.9, 125.8, 125.7, 47.2, 36.9, 29.8, 28.7, 21.5, 0.0. MS (EI, 70 eV): m/z (%) = 347 (3) [M+], 99 (100). Anal. Calcd for C18H25NO2SSi: C, 62.21; H, 7.25; N, 4.03. Found: C, 61.98; H, 7.35; N, 3.93. Compound 13: Mp 121-122 °C. 1H NMR (400 MHz, CDCl3): δ = 7.52 (m, 2 H), 7.44 (m, 2 H), 7.32 (m, 2 H), 7.22 (m, 3 H), 5.77 (m, 1 H), 5.70 (m, 1 H), 3.54 (m, 2 H), 3.38 (m, 1 H), 2.78 (m, 1 H), 2.40 (s, 3 H), 2.23 (m, 1 H), 2.11 (m, 1 H), 1.55 (m, 1 H). 13C NMR (100 MHz, CDCl3): δ = 143.4, 141.0, 134.1, 129.4, 128.0, 127.6, 125.4, 125.3, 124.8, 47.7, 38.0, 33.3, 29.3, 21.6. Compound 14: Oil. 1H NMR (400 MHz, CDCl3) δ = 7.67 (d, J = 8.2 Hz, 2 H), 7.27 (d, J = 8.2 Hz, 2 H), 5.67 (m, 1 H), 5.54 (m, 1 H), 3.42 (m, 2 H), 2.89 (m, 1 H), 2.60 (m, 2 H), 2.41 (s, 3 H), 2.34 (m, 1 H), 1.87 (m, 2 H), 1.52 (m, 1 H), 1.38 (m, 3 H), 1.28 (m, 1 H), 0.93 (t, J = 7.2 Hz, 3 H). 13C NMR (100 MHz, CDCl3) δ = 143.5, 134.6, 131.8, 129.5, 128.5, 127.8, 125.7, 124.8, 47.9, 36.8, 32.0, 31.0, 29.6, 29.4, 22.9, 21.5, 14.0.

12

Crystal data for 12: C13H18NOF3Si, triclinic, space group
P1 (No. 2), a = 8.896 (2), b = 9.643 (2), c = 9.830 (2) Å, α = 102.38 (3)°, β = 115.97 (3)°, γ = 92.73 (3)°, V = 730.8 (3) Å3, Z = 2, D c = 1.315 g cm-3, F (000) = 304,
µ (Mo-Kα) = 1.85 cm-1. 6235 reflections collected, 2650 independent [R(int) = 0.0449], which were used in all calculations. 172 parameters, R 1 = 0.0457, wR 2 = 0.1129 for observed reflections [F2>2σ(F2)] and R 1 = 0.0597, wR 2 = 0.1217 for all reflections, GoF (on F2) = 0.871. Max. and min. residual electron densities: 0.285 and -0.231 eÅ-3. Data were collected on a STOE-IPDS at r.t., the structure was solved by direct methods using SHELXS-97 and refined using SHELXL-97. CCDC: 194177.