Synlett 2008(15): 2271-2274  
DOI: 10.1055/s-2008-1078271
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

A Catalytic Asymmetric Fujiwara-Moritani Cyclization

Julia A. Schiffner, Axel B. Machotta, Martin Oestreich*
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149 Münster, Germany
Fax: +49(251)8336501; e-Mail: martin.oestreich@uni-muenster.de;
Further Information

Publication History

Received 15 May 2008
Publication Date:
21 August 2008 (online)

Abstract

An enantioselective intramolecular Fujiwara-Moritani reaction involving direct C-H functionalization using modified PyOX ligands is reported for the first time. Screening of several ligand-oxidant combinations eventually produced a stereogenic quaternary carbon with promising enantiocontrol (54% ee) and in good chemical yield (71%).

    References and Notes

  • 1 The Mizoroki-Heck Reaction   Oestreich M. Wiley; Chichester: 2008. in press
  • 2a Fujiwara Y. Kitamura T. In Handbook of C-H Transformations   Dyker G. Wiley-VCH; Weinheim: 2005.  p.194 
  • 2b Leeuwen PWNM. de Vries JG. In Handbook of C-H Transformations   Dyker G. Wiley-VCH; Weinheim: 2005.  p.203 
  • 2c Li Z. Li C.-J. In New Frontiers in Asymmetric Catalysis   Mikami K. Lautens M. Wiley; Hoboken: 2007.  p.129 
  • 2d Trepohl VT. Oestreich M. In Modern Arylation Methods   Ackermann L. Wiley-VCH; Weinheim: 2008. in press
  • 3a Moritani I. Fujiwara Y. Tetrahedron Lett.  1967,  1119 
  • 3b Fujiwara Y. Moritani I. Danno S. Asano R. Teranishi S. J. Am. Chem. Soc.  1969,  91:  7166 
  • 3c For an early summary, see: Moritani I. Fujiwara Y. Synthesis  1973,  524 
  • 4 Dieck HA. Heck RF. J. Org. Chem.  1975,  40:  1083 
  • 5a Mizoroki T. Mori K. Ozaki A. Bull. Chem. Soc. Jpn.  1971,  44:  581 
  • 5b Heck RF. Nolley JP., Jr. J. Org. Chem.  1972,  37:  2320 
  • 6 Jia C. Piao D. Oyamada J. Lu W. Kitamura T. Fujiwara Y. Science  2000,  287:  1992 
  • 7a t-BuOOH-1,4-benzoquinone: Jia C. Lu W. Kitamura T. Fujiwara Y. Org. Lett.  1999,  1:  2097 
  • 7b O2-H7PMo8V4O40: Yokota T. Tani M. Sakaguchi S. Ishii Y. J. Am. Chem. Soc.  2003,  125:  1476 
  • 7c O2-Mn(OAc)3: Dams M. de Vos DE. Celen S. Jacobs PA. Angew. Chem. Int. Ed.  2003,  42:  3512 ; Angew. Chem. 2003, 115, 3636
  • Palladium(II)-catalyzed oxidative, intermolecular Heck reactions through transmetalation of boronic acids or esters:
  • 8a Cu(OAc)2: Du X. Suguro M. Hirabayashi K. Mori A. Nishikata T. Hagiwara N. Kawata K. Okeda T. Wang HF. Fugami K. Kosugi M. Org. Lett.  2001,  3:  3313 
  • 8b O2: Jung YC. Mishra RK. Yoon CH. Jung KW. Org. Lett.  2003,  5:  2231 
  • 8c O2: Andappan MMS. Nilsson P. Larhed M. Chem. Commun.  2004,  218 
  • 8d O2: Yoon CH. Yoo KS. Yi SW. Mishra RK. Jung KW. Org. Lett.  2004,  6:  4037 
  • 8e O2: Andappan MMS. Nilsson P. von Schenck H. Larhed M. J. Org. Chem.  2004,  69:  5212 
  • 8f O2 and base-free: Yoo KS. Yoon CH. Jung KW. J. Am. Chem. Soc.  2006,  128:  16384 
  • 8g O2 or 1,4-benzoquinone: Lindh J. Enquist P.-A. Pilotti A. Nilsson P. Larhed M. J. Org. Chem.  2007,  72:  7957 
  • 8h O2- and base-free: Ruan J. Li X. Saidi O. Xiao J. J. Am. Chem. Soc.  2008,  130:  2424 
  • Indoles:
  • 9a Grimster NP. Gauntlett C. Godfrey CRA. Gaunt MJ. Angew. Chem. Int. Ed.  2005,  44:  3125 ; Angew. Chem. 2005, 117, 3185
  • 9b Capito E. Brown JM. Ricci A. Chem. Commun.  2005,  1854 
  • 9c Pyrroles: Beck EM. Grimster NP. Hatley R. Gaunt MJ. J. Am. Chem. Soc.  2006,  128:  2528 
  • 10 Bingham AJ. Dyall LK. Norman ROC. Thomas CB. J. Chem. Soc. C  1970,  1879 
  • 11a Furukawa H. Yogo M. Ito C. Wu T.-S. Kuoh C.-S. Chem. Pharm. Bull.  1985,  33:  1320 
  • 11b Bittner S. Krief P. Massil T. Synthesis  1991,  215 
  • 11c Yogo M. Ito C. Furukawa H. Chem. Pharm. Bull.  1991,  39:  328 
  • 11d Knölker H.-J. O’Sullivan N. Tetrahedron Lett.  1994,  35:  1695 
  • 12a Trost BM. Godleski SA. Genêt JP. J. Am. Chem. Soc.  1978,  100:  3930 
  • 12b Trost BM. Godleski SA. Belletire JL. J. Org. Chem.  1979,  44:  2052 
  • 12c Cushing TD. Sanz-Cervera JF. Williams RM. J. Am. Chem. Soc.  1993,  115:  9323 
  • 12d Cushing TD. Sanz-Cervera JF. Williams RM. J. Am. Chem. Soc.  1996,  118:  557 
  • 12e Williams RM. Cao J. Tsujishima H. Cox RJ. J. Am. Chem. Soc.  2003,  125:  12172 
  • 12f Baran PS. Corey EJ. J. Am. Chem. Soc.  2002,  124:  7904 
  • 12g Baran PS. Guerrero CA. Corey EJ. J. Am. Chem. Soc.  2003,  125:  5628 
  • 12h Garg NK. Caspi DD. Stoltz BM. J. Am. Chem. Soc.  2004,  126:  9552 
  • 12i Garg NK. Caspi DD. Stoltz BM. J. Am. Chem. Soc.  2005,  127:  5970 
  • Oxidative couplings of 1,4-quinones:
  • 13a Cu(OAc)2: Knölker H.-J. O’Sullivan N. Tetrahedron  1994,  50:  10893 
  • 13b Cu(OAc)2: Knölker H.-J. Fröhner W. J. Chem. Soc., Perkin Trans. 1  1998,  173 
  • 13c Knölker H.-J. Reddy KR. Wagner A. Tetrahedron Lett.  1998,  39:  8267 
  • 13d t-BuOOH: Åkermark B. Oslob JD. Heuschert U. Tetrahedron Lett.  1995,  36:  1325 
  • 13e O2: Hagelin H. Oslob JD. Åkermark B. Chem. Eur. J.  1999,  5:  2413 
  • Oxidative indole couplings - O2:
  • 14a Ferreira EM. Stoltz BM. J. Am. Chem. Soc.  2003,  125:  9578 
  • 1,4-Benzoquinone:
  • 14b Abbiati G. Beccalli EM. Broggini G. Zoni C. J. Org. Chem.  2003,  68:  7625 
  • 14c Kong A. Han X. Lu X. Org. Lett.  2006,  8:  1339 
  • 15 Oxidative couplings of electron-rich arenes: Zhang H. Ferreira EM. Stoltz BM. Angew. Chem. Int. Ed.  2004,  43:  6144 ; Angew. Chem. 2004, 116, 6270
  • 16 Dounay AB. Overman LE. Chem. Rev.  2003,  103:  2945 
  • 17 To date, only a single enantioselective intermolecular Fujiwara-Moritani reaction initiated by C-H bond activation is known (49% ee, 19% using PhCO3 t-Bu as the stoichiometric oxidant): Mikami K. Hatano M. Terada M. Chem. Lett.  1999,  55 
  • Very recently, several approaches to enantioselective oxidative Heck reactions initiated by transmetalation appeared in the literature:
  • 18a Akiyama K. Wakabayashi K. Mikami K. Adv. Synth. Catal.  2005,  347:  1569 
  • 18b Penn L. Shpruhman A. Gelman D. J. Org. Chem.  2007,  72:  3875 
  • 18c Yoo KS. Park CP. Yoon CH. Sakaguchi S. O’Neill J. Jung KW. Org. Lett.  2007,  9:  3933 
  • 19 Akiyama K. Mikami K. Heterocycles  2007,  74:  827 
  • 20 Nishimura T. Onoue T. Ohe K. Uemura S. J. Org. Chem.  1999,  64:  6750 
  • Detailed procedures and characterization data will be reported elsewhere. See:
  • 22a L2: Bolm C. Weickhardt K. Zehnder M. Ranff T. Chem. Ber.  1991,  124:  1173 
  • 22b L3-8 were prepared on the basis of a reported sequence: Oila MJ. Tois JE. Koskinen AMP. Tetrahedron  2005,  61:  10748 
  • 23a

    Analytical Data for ( Z )- or ( E )-1-Methyl-3-(3-methylpent-3-enyl) indole [( Z )-1 or ( E )-1] ¹4a
    (Z)-1 (Z/E > 99:1): ¹H NMR (300 MHz, CDCl3): δ = 1.62 (d, J = 6.7 Hz, 3 H), 1.82-1.86 (m, 3 H), 2.48 (br t, J = 8.4 Hz, 2 H), 2.83-2.91 (m, 2 H), 3.78 (s, 3 H), 5.32 (q, J = 6.7 Hz, 1 H), 6.90 (s, 1 H), 7.13-7.20 (m, 1 H), 7.24-7.31 (m, 1 H), 7.31-7.36 (m, 1 H), 7.68 (ddd, J = 7.8, 1.7, 0.9 Hz, 1 H) ppm. ¹³C NMR (75 MHz, CDCl3): δ = 13.3, 23.4, 23.5, 32.5, 32.5, 109.1, 115.3, 118.5, 118.9, 119.2, 121.4, 125.8, 127.9, 136.1, 137.0 ppm.
    (E)-1 (E:Z > 99:1): ¹H NMR (300 MHz, CDCl3): δ = 1.67 (dq, J = 6.7, 1.0 Hz, 3 H), 1.77 (m, 3 H), 2.39-2.49 (m, 2 H), 2.87-2.94 (m, 2 H), 3.78 (s, 3 H), 5.37 (qq, J = 6.8, 1.3 Hz, 1 H), 6.88 (s, 1 H), 7.16 (ddd, J = 8.0, 6.8, 1.3 Hz, 1 H), 7.27 (ddd, J = 8.2, 6.8, 1.2 Hz, 1 H), 7.33 (ddd, J = 8.2, 1.1, 0.9 Hz, 1 H), 7.66 (ddd, J = 7.8, 0.9 Hz, 1 H) ppm. ¹³C NMR (75 MHz, CDCl3): δ = 13.4, 15.8, 24.0, 32.5, 40.5, 109.0, 115.3, 118.4, 118.4, 119.0, 121.3, 125.8, 127.9, 135.9, 136.9 ppm.

  • 23b

    Analytical Data for (-)-3,4-Dimethyl-3-vinyl-1,2,3,4-tetrahydrocyclopenta[ b ]indole [(-)-2]
    [α]D ²0 -17.7 (c 0.565, CHCl3) for 44% ee (Table  [³] , entry 2). HPLC (Daicel Chiralcel IB column using n-heptane at 15 ˚C): t R = 13.9 min (minor enantiomer) and 16.1 min (major enantiomer). IR (film): 3052 (m), 2926 (s), 2854 (s), 1465 (s) cm. ¹H NMR (300 MHz, CDCl3): δ = 1.50 (s, 3 H), 2.36 (ddd, J = 13.0, 7.1, 6.1 Hz, 1 H), 2.47-2.58 (m, 1 H), 2.83 (m, 2 H), 3.64 (s, 3 H), 4.98 (dd, J = 17.4, 1.3 Hz, 1 H), 5.06 (dd, J = 10.5, 1.2 Hz, 1 H), 6.09 (dd, J = 17.4, 10.5 Hz, 1 H), 7.09 (ddd, J = 7.5, 7.1 Hz, 1.3 Hz, 1 H), 7.16 (ddd, J = 8.2, 7.0, 1.4 Hz, 1 H), 7.26 (ddd, J = 8.1, 0.9, 0.8 Hz, 1 H), 7.47 (ddd, J = 7.6, 1.3, 0.7 Hz, 1 H) ppm. ¹³C NMR (75 MHz, CDCl3): δ = 22.5, 23.7, 30.0, 46.0, 46.3, 109.3, 111.8, 117.3, 118.8, 119.0, 120.2, 123.9, 141.6, 145.1, 148.7 ppm. ESI-HRMS: m/z calcd for C15H17NNa: 234.1259; found: 234.1253. Anal. Calcd for C15H17N: C, 85.26; H, 8.11; N, 6.63. Found: C, 84.97; H, 8.20; N, 6.54.

21

General Procedure for Fujiwara-Moritani Cyclization A flame-dried reaction vessel equipped with a magnetic stir bar is charged with Pd(OAc)2 (10 mol%) as well as the indicated ligand L2-8 (30 mol%) and subsequently evacuated and then backfilled with O2 if used as oxidant (three cycles). Otherwise, a solution of the indole and tert-amyl alcohol (0.125 M) and AcOH (0.25 mL per mL of tert-amyl alcohol) are consecutively added. The reaction mixture is maintained at r.t. until a homogeneous tawny solution forms. Then, the oxidant (1.0 equiv), PhCO3 t-Bu or 1,4-benzoquinone, is added, and the resulting reaction mixture is heated at 80 ˚C for 15 h (under O2 atmosphere with O2 as the oxidant). After cooling to r.t., the reaction mixture is diluted with MTBE and poured into H2O. The organic layer is separated and washed with sat. aq NaHCO3 and brine. The aqueous phase is extracted with MTBE and the combined organic extracts are dried over Na2SO4. The solvents are evaporated under reduced pressure, and the residue is purified by flash column chromatography on SiO2 using cyclohexane-MTBE solvent mixtures.