Proline-Catalyzed Asymmetric Direct Aldol Reaction Assisted by d-Camphorsulfonic Acid in Aqueous Media

Yin-Su Wu; Yi Chen; Dong-Sheng Deng; Jiwen Cai

doi:10.1055/s-2005-869864

LETTER

Proline-Catalyzed Asymmetric Direct Aldol Reaction Assisted by d-Camphorsulfonic Acid in Aqueous Media

Yin-Su Wu^a,b, Yi Chen^a, Dong-Sheng Deng^a, Jiwen Cai*^a
^a School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
^b Chemistry college, Hebei Normal University, Shijiazhuang 050016, P. R. China
Fax: +86(20)84112245; e-Mail: puscjw@zsu.edu.cn;

Abstract

All articles of this category

Abstract

Asymmetric aldol reactions of aromatic aldehydes with various ketones catalyzed by l-proline with d-camphorsulfonic acid as co-catalyst have been developed in aqueous media. High reactivity and modest to excellent enantioselectivity has been achieved.

Keywords

asymmetric direct aldol reaction - co-catalyst - proline - camphorsulfonic acid - aqueous media

Full Text

References

<A NAME="RU05405ST-1A">1a</A> List B. Lerner RA. Barbas CF. J. Am. Chem. Soc. 2000, 122: 2395

<A NAME="RU05405ST-1B">1b</A> Sakthivel K. Notz W. Bui T. Barbas CF. J. Am. Chem. Soc. 2001, 123: 5260

<A NAME="RU05405ST-2A">2a</A> Ward DE. Jheengut V. Tetrahedron Lett. 2004, 45: 8347

<A NAME="RU05405ST-2B">2b</A> Notz W. List B. J. Am. Chem. Soc. 2000, 122: 7386

<A NAME="RU05405ST-2C">2c</A> List B. Tetrahedron 2002, 58: 5573

<A NAME="RU05405ST-2D">2d</A> Chandrasekhar S. Narsihmulu C. Reddy NR. Sultana SS. Tetrahedron Lett. 2004, 45: 4581

<A NAME="RU05405ST-2E">2e</A> Hayashi Y. Tsuboi W. Shoji M. Suzuki N. Tetrahedron Lett. 2004, 45: 4353

<A NAME="RU05405ST-2F">2f</A> Pan QB. Zou BL. Wang YJ. Ma DW. Org. Lett. 2004, 6: 1009

<A NAME="RU05405ST-2G">2g</A> Szollosi G. London G. Balaspiri L. Somlai C. Bartok M. Chirality 2004, 15: 90

<A NAME="RU05405ST-2H">2h</A> Liu HW. Peng LZ. Zhang T. Li YL. New J. Chem. 2004, 27: 1159

<A NAME="RU05405ST-2I">2i</A> Kotrusz P. Kmentova I. Gotov B. Toma S. Solcaniova E. Chem. Commun. 2002, 2510

<A NAME="RU05405ST-3A">3a</A> Notz W. Tanaka F. Barbas CF. Acc. Chem. Res. 2004, 37: 580

<A NAME="RU05405ST-3B">3b</A> Saito S. Yamamoto H. Acc. Chem. Res. 2004, 37: 570

<A NAME="RU05405ST-3C">3c</A> Nakadai M. Satio S. Yamamoto H. Tetrahedron 2002, 58: 8167

<A NAME="RU05405ST-3D">3d</A> Tang Z. Jiang F. Yu L.-T. Cui X. Gong L.-Z. Mi A.-Q. Jiang Y.-Z. Wu Y.-D. J. Am. Chem. Soc. 2003, 125: 5262

<A NAME="RU05405ST-3E">3e</A> Tang Z. Jiang F. Cui X. Gong LZ. Mi AQ. Jiang YZ. Wu YD. Proc. Natl. Acad. Sci. U.S.A. 2004, 101: 5755

<A NAME="RU05405ST-3F">3f</A> Hayashi Y. Yamaguchi J. Hibino K. Sumiya T. Urushima T. Shoji M. Hashizume D. Koshino H. Adv. Synth. Catal. 2004, 346: 1435

<A NAME="RU05405ST-3G">3g</A> Berkessel A. Koch B. Lex J. Adv. Synth. Catal. 2004, 346: 1141

<A NAME="RU05405ST-3H">3h</A> Tang Z. Yang ZH. Cun LF. Gong LZ. Mi AQ. Jiang YZ. Org. Lett. 2004, 6: 2285

<A NAME="RU05405ST-4A">4a</A> Torii H. Nakadai M. Ishihara K. Saito S. Yamamoto H. Angew. Chem. Int. Ed. 2004, 43: 1983

<A NAME="RU05405ST-4B">4b</A> Hartikka A. Arvidsson PI. Tetrahedron: Asymmetry 2004, 15: 1831

<A NAME="RU05405ST-5">5</A> Mase N. Tanaka F. Barbas CF. Angew. Chem. Int. Ed. 2004, 43: 2420

<A NAME="RU05405ST-6">6</A> Córdova A. Notz W. Barbas CF. Chem. Commun. 2002, 3024

<A NAME="RU05405ST-7">7</A> Nyberg AI. Usano A. Pihko PM. Synlett 2004, 1891

<A NAME="RU05405ST-8">8</A> Peng Y.-Y. Ding Q.-P. Li Z. Wang PG. Cheng J.-P. Tetrahedron Lett. 2003, 44: 3871

<A NAME="RU05405ST-9">9</A> Wu Y.-S. Shao W.-Y. Zheng C.-Q. Huang Z.-L. Cai J. Deng Q.-Y. Helv. Chim. Acta 2004, 87: 1377

<A NAME="RU05405ST-10">10</A> Darbre T. Machuqueiro M. Chem. Commun. 2003, 1090

<A NAME="RU05405ST-11">11</A> Wu Y.-S. Cai J. Hu Z.-Y. Lin G.-X. Tetrahedron Lett. 2004, 45: 8949

Typical Procedure (Table [1] , entry 3): Anhyd acetone (2.0 mL, dried with K₂CO₃ before use) was added to p-nitro-benzaldehyde (75 mg, 0.5 mmol), followed by l-proline (20 mol%) and d-CSA (10 mol%) dissolved in water (0.5 mL). The resulting mixture was stirred at r.t. for 12 h. After treating the reaction mixture with saturated aq NaHCO₃ (5 mL), the aqueous layer was separated, and extracted with EtOAc three times. The combined organic extracts were washed with brine (5 mL), dried over anhyd Mg₂SO₄, and concentrated. The residue was purified by preparative thin layer chromatography (Silica gel plates GF254, hexane-EtOAc) to give the aldol product (76.3 mg). The anti/syn ratio is established by ¹H NMR; d = 4.83 ppm (J = 9.0 Hz) - CH of the anti-isomer; 5.42 ppm (J = 2.7 Hz) - CH of the syn-isomer (Table [4] , entry 1). The ee values were determined by HPLC, Daicel chiralpak AS-RH.

<A NAME="RU05405ST-13">13</A> Mestres R. Green Chem. 2004, 6: 583