Au₂O₃ as a Stable and Efficient Catalyst for the Selective Cycloisomerization of γ-Acetylenic Carboxylic Acids to γ-Alkylidene-γ-Butyrolactones

Abstract

The high potential of commercially available Au₂O₃ as a catalyst in the cyclization of alkynes bearing carboxylic acids to the corresponding γ-alkylidene-γ-butyrolactones through a general, efficient and easy procedure is presented. The reaction shows a high degree of chemo-, regio-, and stereoselectivity. The 5-exo mode of cyclization and anti auration are a general trend for the Au₂O₃ catalyst.

Keywords

gold catalyst - cycloisomerization - γ-acetylenic carboxylic acids - atom economy - γ-alkylidene-γ-butyrolactones

References and Notes

• For representative examples and seminal references, see:
• 1a Fürstner A. Davies PW. Angew Chem. Int. Ed.  2007,  46:  3410 
• 1b Gorin DJ. Toste D. Nature (London)  2007,  446:  395 
• 1c Hashmi ASK. Hutchings GJ. Angew Chem. Int. Ed.  2006,  45:  7896 
• 1d Jiménez-Núñez E. Echavarren AM. Chem. Commun.  2007,  333 
• 1e Ma S. Yu S. Gu Z. Angew. Chem. Int. Ed.  2006,  45:  200 
• 1f Hashmi ASK. Angew. Chem. Int. Ed.  2005,  44:  6090 
• 1g Hoffmann-Röder A. Krause N. Org. Biomol. Chem.  2005,  3:  387 
• 1h Hashmi ASK. Gold Bull.  2004,  37:  51 
• 1i Pyykkö P. Angew. Chem. Int. Ed.  2004,  43:  4412 
• 1j Hashmi ASK. Chem. Rev.  2007,  107:  3180 
• 1k Shaw CF. Chem. Rev.  1999,  99:  2589 
• 1l Michelet V. Toullec PY. Genet J.-P. Angew. Chem. Int. Ed.  2008,  47:  in press
• 2a Zhang L. Sun J. Kozmin SA. Adv. Synth. Catal.  2006,  348:  2271 
• 2b Nieto-Oberhuber C. López S. Jiménez-Núñez E. Echavarren AM. Chem. Eur. J.  2006,  12:  5916 
• 2c Nevado C. Echavarren AM. Synthesis  2005,  167 
• 2d Arcadi A. Di Giuseppe S. Curr. Org. Chem.  2004,  8:  795 
• 2e Bianchi G. Arcadi A. In Targets in Heterocyclic Systems   Vol. 8:  Attanasi OA. Spinelli D. Springer; Berlin: 2004.  p.82 
• 2f Aubert C. Fensterbank L. Gandon V. Malacria M. Topics Organomet. Chem.  2006,  19:  259 
• For a review discussing natural products exhibiting the γ-butyrolactone substructure, see:
• 3a Koch SSC. Chamberlin AR. In Studies in Natural Products Chemistry   Vol. 16:  . Elsevier Science; Amsterdam: 1995.  p.687 
• For reviews discussing the synthetic routes to γ-alkylydene-γ-butyrolactones, see:
• 3b Seitz M. Reiser O. Curr. Opin. Chem. Biol.  2005,  9:  285 
• 3c Negishi E.-I. Kotora M. Tetrahedron  1997,  53:  6707 
• For representative examples from Pd chemistry, see:
• 3d Balme G. Monteiro N. Bouyssi D. Handbook of Organopalladium Chemistry for Organic Synthesis   Negishi E.-I. John Wiley and Sons; New York: 2002.  p.2245-2265  
• 3e Hosokawa T. Murahashi S.-I. Handbook of Organopalladium Chemistry for Organic Synthesis   Negishi E.-I. John Wiley and Sons; New York: 2002.  p.2169-2192  
• 3f Xu C. Negishi E.-I. Handbook of Organopalladium Chemistry for Organic Synthesis   Negishi E.-I. John Wiley and Sons; New York: 2002.  p.2289 
• For specific cases of natural product synthesis where cyclizations of alkynoic acids constitute a key step, see:
• 4a Algueró M. Bosch J. Castañer J. Castellá J. Castells J. Mestres R. Pascual J. Serratosa F. Tetrahedron  1962,  18:  1381 
• 4b Jong TT. Williard PG. Porwoll JP. J. Org. Chem.  1984,  49:  735 
• 4c Imagawa H. Fujikawa Y. Tsuchihiro A. Kinoshita A. Yoshinaga T. Takao H. Nishizawa N. Synlett  2006,  639 
• 5a Wright AD. de Nys R. Angerhofer CK. Pezzuto JM. Gurrath M. J. Nat. Prod.  2006,  69:  1180 
• 5b Chen C.-H. Lo W.-L. Liu Y.-C. Chen C.-Y. J. Nat. Prod.  2006,  69:  927 
• For comprehensive reviews dealing with transition-metal-catalyzed heteroatom-hydrogen additions to alkynes, see:
• 6a Alonso F. Beletskaya IP. Yus M. Chem. Rev.  2004,  104:  3079 
• 6b Beller M. Seayad J. Tillack A. Jiao H. Angew. Chem. Int. Ed.  2004,  43:  3368 
• 6c Nakamura I. Yamamoto Y. Chem. Rev.  2004,  104:  2127 
• 6d For Ru-catalyzed intermolecular reactions, see: Bruneau C. Dixneuf PH. Acc. Chem. Res.  1999,  32:  311 
• Silver catalysis:
• 7a Castaner J. Pascual J. J. Chem. Soc.  1958,  3962 
• 7b Pale P. Chuche J. Tetrahedron Lett.  1987,  27:  6447 
• 7c Dalla V. Pale P. New. J. Chem.  1999,  23:  803 
• 7d Dalla V. Pale P. Tetrahedron Lett.  1994,  35:  3525 
• 7e Oh CH. Yi HJ. Lee JH. New. J. Chem.  2007,  31:  835 
• Mercury catalysis:
• 8a Yamamoto M. J. Chem. Soc., Chem. Commun.  1978,  649 
• 8b Yamamoto M. J. Chem. Soc., Perkin Trans. 1  1981,  582 
• 8c Amos RA. Katzenellenbogen JA. J. Org. Chem.  1978,  43:  560 
• 8d Amos RA. Katzenellenbogen JA. J. Am. Chem. Soc.  1981,  103:  5459 
• 8e Rollinson SW. Amos RA. Katzenellenbogen JA. J. Am. Chem. Soc.  1981,  103:  4114 
• 8f Sofia MJ. Katzenellenbogen JA. J. Org. Chem.  1984,  50:  2331 
• 8g Spencer RW. Tam TF. Thomas E. Robinson VJ. Krantz A. J. Am. Chem. Soc.  1986,  108:  5589 
• Palladium catalysis:
• 9a Lambert C. Utimoto K. Nozaki H. Tetrahedron Lett.  1984,  25:  5323 
• 9b Yanagihara N. Lambert C. Iritari K. Utimoto K. Nozaki H. J. Am. Chem. Soc.  1986,  108:  2753 
• 9c Arcadi A. Burini A. Cacchi S. Delmastro M. Marinelli F. Pietroni BR. J. Org. Chem.  1992,  57:  976 
• 9d Cavicchioli M. Bouyssi D. Goré J. Balme G. Tetrahedron Lett.  1996,  37:  1429 
• 9e Wang X. Lu X. J. Org. Chem.  1996,  61:  2254 
• 9f Huo Z. Patil NT. Jin T. Pahadi NK. Yamamoto Y. Adv. Synth. Catal.  2007,  349:  680 
• 9g Bellina F. Ciucci D. Vergamini P. Rossi R. Tetrahedron  2000,  56:  2533 
• 9h Ahmed Z. Albrecht U. Langer P. Eur. J. Org. Chem.  2005,  3469 
• 9i Subramanian V. Batchu VR. Barange D. Pal M. J. Org. Chem.  2005,  70:  4778 
• 9j Duchêne A. Thibonnet J. Parrain J.-L. Anselmi E. Abarbri M. Synthesis  2007,  597 
• 10 Ruthenium catalysis: Jimenez-Tenotio M. Puerta MC. Valerga P. Moreno-Dorado FJ. Guerra FM. Massanet GM. Chem. Commun.  2001,  2324 
• Rhodium catalysis:
• 11a Marder TB. Chan DMT. Fultz WC. Calabrese JC. Milstein D. J. Chem. Soc., Chem Commun.  1987,  1885 
• 11b Chan DMT. Marder TB. Milstein D. Taylor NJ. J. Am. Chem. Soc.  1987,  109:  6385 
• 11c Elgafi S. Field LD. Messerle BA. J. Organomet. Chem.  2000,  607:  97 
• Cluster catalysis:
• 12a Wakabayashi T. Ishii Y. Ishikawa K. Hidai M. Angew. Chem., Int. Ed. Engl.  1996,  35:  3123 ; and references cited therein
• 12b Takei I. Wakebe Y. Suzuki K. Enta Y. Suzuki T. Mizobe Y. Hidai M. Organometallics  2003,  22:  4639 
• 13a Charruault L. Michelet V. Taras R. Gladiali S. Genêt J.-P. Chem. Commun.  2004,  850 
• 13b Nevado C. Charruault L. Michelet V. Nieto-Oberhuber C. Muñoz MP. Méndez M. Rager M.-N. Genêt J.-P. Echavarren AM. Eur. J. Org. Chem.  2003,  706 
• 13c Antoniotti S. Genin E. Michelet V. Genêt J.-P. J. Am. Chem. Soc.  2005,  127:  9976 
• 13d Genin E. Antoniotti S. Michelet V. Genêt J.-P. Angew. Chem. Int. Ed.  2005,  44:  4949 
• 13e Toullec PY. Genin E. Leseurre L. Genêt J.-P. Michelet V. Angew. Chem. Int. Ed.  2006,  45:  7427 
• 13f Genin E. Leseurre L. Toullec PY. Genêt J.-P. Michelet V. Synlett  2007,  1780 
• 13g Leseurre L. Toullec PY. Genêt J.-P. Michelet V. Org. Lett.  2007,  9:  4049 
• 14a Genin E. Toullec PY. Antoniotti S. Brancour C. Genêt J.-P. Michelet V. J. Am. Chem. Soc.  2006,  128:  3112 
• 14b Genin E. Toullec PY. Antoniotti S. Brancour C. G enêt J.-P. Michelet V. ARKIVOC  2007,  (v):  67 
• For references dealing with the gold-catalyzed hydration of alkynes, see:
• 15a Fukuda Y. Utimoto K. J. Org. Chem.  1991,  56:  3729 
• 15b Teles JH. Brode S. Chabanas M. Angew. Chem. Int. Ed.  1998,  37:  1415 
• 15c Mizushima E. Sato K. Hayashi TM. Angew. Chem. Int. Ed.  2002,  41:  4563 
• 15d Schneider SK. Herrmann WA. Herdtweck E. Z. Anorg. Allg. Chem.  2003,  629:  2363 
• 16a Harkat H. Weibel J.-M. Pale P. Tetrahedron Lett.  2006,  47:  6273 
• 16b For a recent Au-catalyzed cyclization of γ- and δ-acetylenic acids, see: Marchal E. Uriac P. Legoin B. Toupet L. van de Weghe P. Tetrahedron  2007,  63:  9979 
• 17a Jones CJ. Taube D. Ziatdinov VR. Periana RA. Nielsen RJ. Oxgaard J. Goddard WA. Angew. Chem. Int. Ed.  2004,  43:  4626 
• 17b De Vos DE. Sels BF. Angew. Chem. Int. Ed.  2005,  44:  30 

18

General Procedure for the Cycloisomerization of γ-Acetylenic Acid 1
Substrate 1b (98 mg, 1 mmol) was placed in 5 mL Schlenk tube under argon and 1 mL of degassed MeCN was added. Gold(III) oxide (11.1 mg, 0,025 mmol) was added and the reaction mixture stirred at r.t. for 2 h. Filtration of the reaction mixture on a pad of 2 cm of silica using 15 mL of EtOAc and evaporation of the solvents allowed the isolation of product 2b as colorless oil in an analytically pure form (89 mg, 90% yield).

19

2-(Methoxycarbonyl)-2-(prop-2-ynyl)hex-5-ynoic Acid (1i)
Substrate 1i was prepared in a two-step procedure using malonic synthesis. Sodium hydride (1.1 equiv, 60 wt.% in mineral oil) was added portionwise at 0 °C to a solution of dimethyl propargylmalonate (1 equiv) in anhydrous DMF. The reaction was allowed to warm up to r.t. and but-3-ynyl trifluoromethylsulfonate ester (1.1 equiv) slowly added. The mixture was stirred at r.t. overnight, quenched upon addition of 10 mL of H₂O and extracted with Et₂O (3 × 20 mL). The combined organic layers were washed with brine (30 mL), dried over MgSO₄, and solvents evaporated under reduced pressure. Dimethyl 2-(but-3-ynyl)-2-(prop-2-ynyl)malonate was obtained as a colorless oil (18%) after purification by silica gel chromatography (cyclohexane-EtOAc, 90:10). Monosaponification was conducted following a reported procedure.¹⁴ A solution of KOH (1.2 equiv) in anhydrous MeOH (0.4 mol/L) was added to a cooled (0 °C) solution of substrate (1 equiv) in anhydrous MeOH (0.4 mol/L). The mixture was stirred at r.t. for 6 h. Solvent was removed under reduced pressure and the crude product redissolved in Et₂O. The organic layer was treated three times with sat. NaHCO₃, the aqueous phases collected, acidified to pH 1 with concd HCl, and then extracted with Et₂O. This organic layer was then dried over MgSO₄ and the solvents removed under reduced pressure to give 1i as a colorless oil (48% yield).
2-Methoxycarbonyl-2-[but-3′-ynyl]-4-methylene-butyrolactone (2i) ¹H NMR (300 MHz, CDCl₃): δ = 4.80-4.83 (m, 1 H), 4.39-4.41 (m, 1 H), 3.79 (s, 3 H), 3.39 (dt, J = 18.9, 2.0 Hz, 1 H), 2.98 (dt, J = 18.9, 2.0 Hz, 1 H), 2.05-2.40 (m, 4 H), 1.99 (t, J = 2.6 Hz, 1 H). ¹³C NMR (75.4 MHz, CDCl₃): δ = 171.9, 168.9, 152.3, 89.9, 82.1, 69.8, 54.6, 53.4, 35.3, 32.6, 14.3. MS (CI, NH₃): m/z (%) = 209 (8) [M + H]⁺, 226 (100) [M + NH₄]⁺, 244 (8) [M + NH₃ + NH₄]⁺. HRMS (CI-NH₃): m/z calcd for C₁₁H₁₃O₄: 209.0814; found: 209.0819.

20

2,2-Dimethylhept-4-ynoic Acid (1l) Methyl isobutyrate (1.07g, 10.5 mmol) was added dropwise at -78 °C to a solution of LDA solution in THF (15 mL, 0.7 mol/L, 10.5 mmol). The solution was stirred at -78 °C for 20 min then 1-bromobut-2-yne (1.47g, 10 mmol) slowly added dropwise. The reaction was stirred at -78 °C for 2 h then allowed to warm up to r.t. The reaction mixture was quenched with sat. aq NaHCO₃ solution and extracted with Et₂O. The combined organic layers were collected, washed with brine, dried over MgSO₄, and the solvents removed under reduced pressure. The crude oil was purified by flash chromatography [PE (30-60)-EtOAc, 95:5] to give methyl 2,2-dimethylhept-4-ynoate as a colorless oil (1.48 g, 88% yield). Saponification was conducted following a published procedure.² Methyl 2,2-dimethylhept-4-ynoate (1.01g, 6 mmol) was added to a solution of KOH (403 mg, 7.2 mmol) in MeOH and the reaction mixture was stirred at r.t. for 16 h. Solvent was removed under reduced pressure and the crude product dissolved in Et₂O. The organic layer was treated three times with sat. Na₂CO₃, the aqueous phases collected, acidified to pH 1 with concd HCl, and then extracted with Et₂O. This organic layer was then dried over MgSO₄ and the solvents removed under reduced pressure to give 1l as a colorless oil (590 mg, 64% yield). ¹H NMR (300 MHz, CDCl₃): δ = 2.41 (t, J = 2.4 Hz, 2 H), 2.16 (qt, J = 7.5, 2.4 Hz, 2 H), 1.28 (s, 3 H), 1.11 (t, J = 7.5 Hz, 1 H). ¹³C NMR (75.4 MHz, CDCl₃): δ = 183.2, 84.3, 75.5, 42.2, 29.7, 24.3, 14.2, 12.4. MS (CI, NH₃): m/z (%) = 155 (15) [M + H]⁺) 172 (100) [M + NH₄]⁺. HRMS (CI-NH₃): m/z calcd for C₉H₁₅O₂: 155.1072; found: 155.1075.
2,2-Dimethyl-4-propylydenebutyrolactone (2l) ¹H NMR (300 MHz, CDCl₃): δ = 4.60 (tt, J = 7.4, 1.7 Hz, 1 H), 2.61 (dt, J = 1.5, 1.5 Hz, 2 H), 2.16 (dtq, J = 7.5, 7.4, 1.4 Hz, 2 H), 1.29 (s, 6 H), 0.98 (t, J = 7.5 Hz, 3 H). ¹³C NMR (75.4 MHz, CDCl₃): δ = 180.4, 144.8, 107.2, 40.8, 40.0, 24.6, 18.5, 14.2. MS (CI, NH₃): m/z (%) 172 (20) [M + NH₄]⁺, 188 (100) [M + NH₄ + H₂O]⁺. HRMS (CI-NH₃): m/z calcd for C₉H₁₅O₂: 155.1072; found: 155.1071.