Palladium-Catalyzed Reaction of Arenediazonium Tetrafluoroborates with Methyl 4-Hydroxy-2-butenoate: An Approach to 4-Aryl Butenolides and an Expeditious Synthesis of Rubrolide E

Abstract

The palladium-catalyzed reaction of arenediazonium ­tetrafluoroborates with methyl 4-hydroxy-2-butenoate in MeOH under mild conditions gives 4-arylbutenolides usually in good to high yields through a domino vinylic substitution/cyclization process. The reaction tolerates a variety of useful substituents including the whole range of halogen substituents, nitro, ether, cyano, keto, and ester groups and can be performed as a one-pot process generating the arenediazonium salt in situ. By using this method, the marine antibiotic rubrolide E has been synthesized via an expeditious and efficient sequential protocol that omits the isolation of the butenolide intermediate (two operative steps, 52% overall yield).

diazonium salts - Heck reaction - cyclization - buten­olides - rubrolides

References and Notes

1 For an excellent recent review on the palladium chemistry of arenediazonium salts, see: Roglans A. Pla-Quintana A. Moreno-Mañas M. Chem. Rev.  2006,  106:  4622 

For some recent selected references, see:

2a Brunner H. Le Cousturier de Courcy N. Genêt J.-P. Synlett  2000,  201 

2b Cai MZ. Hu RH. Zhou J. Chin. Chem. Lett.  2001,  12:  861 

2c Hu R.-H. Liu X.-L. Cai M.-Z. Jiangxi Shifan Daxue Xuebao, Ziran Kexueban  2001,  25:  246 ; Chem. Abstr. 2001, 136, 355024

2d Darses S. Pucheault M. Genêt J.-P. Eur. J. Org. Chem.  2001,  1121 

2e Sengupta S. Bhattacharyya S. Tetrahedron Lett.  2001,  42:  2035 

2f Andrus MB. Song C. Zhang J. Org. Lett.  2002,  4:  2079 

2g Selvakumar K. Zapf A. Spannenberg A. Beller M. Chem. Eur. J.  2002,  8:  3901 

2h Andrus MB. Ma Y. Zang Y. Song C. Tetrahedron Lett.  2002,  43:  9137 

2i Ma Y. Song C. Chai Q. Ma C. Andrus MB. Synthesis  2003,  2886 

2j Wang C. Tan L.-S. He J.-P. Hu H.-W. Xu J.-H. Synth. Commun.  2003,  33:  773 

2k Masllorens J. Moreno-Mañas M. Pla-Quintana A. Roglans A. Org. Lett.  2003,  5:  1559 

2l Schmidt B. Chem. Commun.  2003,  1656 

2m Nelson ML. Ismail MY. McIntyre L. Bhatia B. Viski P. Hawkins P. Rennie G. Andorsky D. Messersmith D. Stapleton K. Dumornay J. Sheahan P. Verma AK. Warchol T. Levy SB. J. Org. Chem.  2003,  68:  5838 

2n Dai M. Liang B. Wang C. Chen J. Yang Z. Org. Lett.  2004,  6:  221 

2o Kabalka GW. Dong G. Venkataiah B. Tetrahedron Lett.  2004,  45:  2775 

2p Xu L.-H. Zhang Y.-Y. Wang X.-L. Chou J.-Y. Dyes Pigm.  2004,  62:  283 

2q Masllorens J. Bouquillon S. Roglans A. Hénin F. Muzart J. J. Organomet. Chem.  2005,  690:  3822 

2r Farina A. Ferranti C. Marra C. Guiso M. Norcia G. Nat. Prod. Res.  2007,  21:  564 

2s Moro AV. Cardoso FSP. Correia CRD. Tetrahedron Lett.  2008,  49:  5668 

For some recent references, see:

3a Severino EA. Costenaro ER. Garcia ALL. Correia CRD. Org. Lett.  2003,  5:  305 

3b Garcia ALL. Correia CRD. Tetrahedron Lett.  2003,  44:  1553 

3c Montes de Oca ACB. Correia CRD. ARKIVOC  2003,  (x):  390 

3d Schmidt B. Chem. Commun.  2003,  1656 

3e Garcia Ariel LL. Carpes MJS. Montes de Oca ACB. dos Santos MAG. Santana CC. Correia CRD. J. Org. Chem.  2005,  70:  1050 

3f Sabino AA. Machado AHL. Correia CRD. Eberlin MN. Angew. Chem. Int. Ed.  2004,  43:  2514 

3g Sabino AA. Machado AHL. Correia CRD. Eberlin MN. Angew. Chem. Int. Ed.  2004,  43:  4389 

3h Pastre JC. Correia CRD. Org. Lett.  2006,  8:  1657 

3i Burtoloso ACB. Garcia ALL. Miranda KC. Correia CRD. Synlett  2006,  3145 

3j Artuso E. Barbero M. Degani I. Dughera S. Fochi R. Tetrahedron  2006,  62:  3146 

3k Meira PRR. Moro AV. Correia CRD. Synthesis  2007,  2279 

3l Peixoto da Silva K. Godoi MN. Correia CRD. Org. Lett.  2007,  9:  2815 

3m Barreto R. Nascimbem LBLR. Correia CRD. Synth. Commun.  2007,  37:  2011 

3n Bartoli G. Cacchi S. Fabrizi G. Goggiamani A. Synlett  2008,  2508 

4 Perez R. Veronese D. Coelho F. Antunes OAC. Tetrahedron Lett.  2006,  47:  1325 

5 Konno T. Yamada S. Tani A. Miyabe T. Ishihara T. Synlett  2006,  3025 

6 Cacchi S. Fabrizi G. Goggiamani A. Persiani D. Org. Lett.  2008,  10:  1597 

Ethyl and methyl 4-hydroxy-2-butenoates were prepared according to literature procedures:

7a Rambaud R. Bull. Soc. Chim. Fr.  1934,  1:  1317 

7b Hassner A. Friedman O. Dehaen W. Liebigs Ann./ Recl.  1997,  587 

8a Bezuidenhoudt BCB. Swanepoel A. Brandt EV. Ferreira D. J. Chem. Soc., Perkin Trans. 1  1990,  2599 

8b Miao S. Andersen RJ. J. Org. Chem.  1991,  56:  6275 

8c Miles DH. Chittawong V. Lho D.-S. Payne AM. de la Cruz AA. Gomez ED. Weeks JA. Atwood JL. J. Nat. Prod.  1991,  54:  286 

8d Nohara T. Kinjo J. Furusawa J. Sakai Y. Inoue M. Shirataki Y. Ishibashi Y. Yokoe I. Komatsu M. Phytochemistry  1993,  33:  1207 

8e Cerri A. Mauri P. Mauro M. Melloni P. J. Heterocycl. Chem.  1993,  30:  1581 

8f Tan L. Chen C.-y. Larsen RD. Verhoeven TR. Reider PJ. Tetrahedron Lett.  1998,  39:  3961 

8g Smith CJ. Hettich RL. Jompa J. Tahir A. Buchanan MV. Ireland CM. J. Org. Chem.  1998,  63:  4147 

9

Typical Procedure for the Preparation of Butenolides (3) To a stirred solution of 2b (58.0 mg, 0.50 mmol) and Pd(OAc)₂ (5.6 mg, 0.025 mmol) in anhyd MeOH (5.0 mL), 1b (250.0 mg, 1.0 mmol) was added at r.t. under argon. The reaction mixture was warmed at 40 ˚C and stirred at that temperature for 4 h (the reactor was protected from light with aluminum film). After cooling, the reaction mixture was diluted with EtOAc, washed with brine, dried over Na₂SO₄, and concentrated under reduced pressure. The residue was purified by chromatography on SiO₂ [n-hexane-EtOAc, 60:40] to afford 83.9 mg of 3b (77% yield); mp: 192-194 ˚C. IR (KBr): 1745, 1710, 1280 cm^-¹. ^¹H NMR (400 MHz, CDCl₃): δ = 8.15 (d, J = 8.4 Hz, 2 H), 7.60 (d, J = 8.4 Hz, 2 H), 6.21 (t, J = 1.6 Hz, 2 H), 5.16 (d, J = 1.6 Hz, 2 H), 3.97 (s, 3 H). ^¹³C NMR (100.6 MHz, CDCl₃): δ = 173.2, 166.0, 162.5, 133.6, 132.9, 130.5, 126.5, 115.3, 70.9, 52.6. MS: m/z (%) = 216 (8) [M⁺], 75 (42), 59 (100).

10 Miao S. Andersen RJ. J. Org. Chem.  1991,  56:  6275 

11 Ortega MJ. Zubia E. Ocana JM. Naranjo S. Salva J. Tetrahedron  2000,  56:  3963 

For selected recent syntheses of rubrolides, see:

12a Bellina F. Anselmi C. Stephane V. Mannina L. Rossi R. Tetrahedron  2001,  57:  9997 

12b Bellina F. Anselmi C. Rossi R. Tetrahedron Lett.  2002,  43:  2023 

12c Bellina F. Anselmi C. Manina F. Rossi R. Eur. J. Org. Chem.  2003,  2290 

12d Boukouvalas J. Pouliot M. Synlett  2005,  343 

12e Kar A. Argade NP. Synlett  2005,  2284 

12f Chavan SP. Pathak AB. Pandey A. Kalkote UR. Synth. Commun.  2007,  37:  4253 

13 Doyle MP. Bryker WJ. J. Org. Chem.  1979,  44:  1572 

14

One-Pot Procedure for the Preparation of Butenolides (3) from Anilines
A solution of BF₃˙OEt₂ (140 µL, 1.1 mmol) in anhyd THF (1 mL) was cooled at -15 ˚C, and 4-carbomethoxylaniline (151.2 mg, 1 mmol) was added. Then, tert-butyl nitrite (160 µL, 1.3 mmol) in 1 mL of the same solvent was added dropwise to the rapidly stirred solution over a 10 min period. After that, the reaction temperature was maintained at -15 ˚C for 10 min, allowed to warm to 5 ˚C (ice-water bath) over a 20 min period, warmed to r.t., and stirred at the same temperature till the disappearance of the starting aniline. The reaction mixture was subsequently concentrated under reduced pressure and diluted with anhyd MeOH (5 mL). Then, 2b (58.0 mg, 0.50 mmol) and Pd(OAc)₂ (5.6 mg, 0.025 mmol) were added, the reaction mixture was warmed at 40 ˚C, and stirred at that temperature for 4 h (the reactor was protected from light with aluminum film). After cooling, the reaction mixture was diluted with EtOAc, washed with brine, dried over Na₂SO₄, and concentrated under reduced pressure. The residue was purified by chromatography on SiO₂ [n-hexane-EtOAc, 60:40] to afford 80.0 mg of 3b (73% yield).