Manganese-Promoted β-Elimination Reactions: Totally Stereoselective Synthesis of (E)-α,β-Unsaturated Esters

Abstract

Stereoselective β-elimination of 2-bromo-3-hydroxy­esters is achieved by using non-preactivated manganese and tri­methylsilyl chloride, to yield (E)-α,β-unsaturated esters with total diastereoselectivity.

alkenes - diastereoselectivity - esters - eliminations - manganese

References and Notes

1 The Chemistry of Alkenes   Vol. 2:  Patai S. Interscience; New York: 1968. 

2 Concellón JM. Pérez-Andrés JA. Rodríguez-Solla H. Angew. Chem. Int. Ed.  2000,  39:  2773 

3 Concellón JM. Rodríguez-Solla H. Méjica C. Tetrahedron Lett.  2004,  45:  2977 

4

Aldrich catalogue (2005-2006): manganese (325 mesh): 250 g - 30.50 ı; samarium (40 mesh): 50 g - 325.20 ı; chromium dichloride: 25 g - 541.80 ı.

5a Concellón JM. Rodríguez-Solla H. Chem. Soc. Rev.  2004,  33:  599 

5b Kagan HB. Tetrahedron  2003,  59:  10351 

5c Steel PG. J. Chem. Soc., Perkin Trans. 1  2001,  2727 

5d Molander GA. Harris CR. Chem. Rev.  1996,  96:  307 

6a Matsubara S. Oshima K. In Modern Carbonyl Olefination   Takeda T. WileyVCH; Weinheim: 2004.  Chap. 5.

6b Fürstner A. Chem. Rev.  1999,  99:  991 

6c Wessjohann LA. Scheid G. Synthesis  1999,  1 

7 For a publication about the effect of TMSCl concerning the activation of Mn⁰, see: Takai K. Ueda T. Hayashi T. Moriwake T. Tetrahedron Lett.  1996,  37:  7049 

8a Fürstner A. Brunner H. Tetrahedron Lett.  1996,  37:  7009 

8b Kim S.-H. Hanson MV. Rieke RD. Tetrahedron Lett.  1996,  37:  2197 

9a Kakiya H. Nishimae S. Shinokubo H. Oshima K. Tetrahedron  2001,  57:  8807 

9b Kim S.-H. Rieke RD. J. Org. Chem.  2000,  65:  2322 

9c Guijarro A. Gómez C. Yus M. Trends Org. Chem.  2000,  8:  65 

9d Cahiez G. Martin A. Delacroix T. Tetrahedron Lett.  1999,  40:  6407 

9e Kim S.-H. Rieke RD. Synth. Commun.  1998,  28:  1065 

9f Kim S.-H. Rieke RD. J. Org. Chem.  1998,  63:  6766 

9g Tang J. Shinokubo H. Oshima K. Synlett  1998,  1075 

9h Rieke RD. Kim S.-H. J. Org. Chem.  1998,  63:  5235 

9i Kim S.-H. Rieke RD. Tetrahedron Lett.  1997,  38:  993 

10 Suh Y. Rieke RD. Tetrahedron Lett.  2004,  45:  1807 

For some examples of synthetic applications of non-activated manganese, see:

11a Cahiez G. Chavant P.-Y. Tetrahedron Lett.  1989,  30:  7373 

11b Hiyama T. Sawahata M. Obayashi M. Chem. Lett.  1983,  1237 

11c

See also ref. 7, 9c.

12a Typical Procedure for Compound 2h. When a solution of 1h (0.4 mmol, 1 equiv) in dry THF (2.5 mL), in the presence of Mn granules (325 mesh, 0.6 mmol, 1.5 equiv), and TMSCl (0.7 mmol, 1.75 equiv), was refluxed for 5 h, compound 2h was obtained after hydrolysis with >98 % de and 91% yield. For spectroscopic data of 1h see ref. 12b.Compound 2h: ¹H NMR (300 MHz, CDCl₃): δ = 7.52-7.27 (6 H, m), 7.09 (1 H, dd, J = 15.3, 10.9 Hz), 6.89 (1 H, d, J = 15.3 Hz), 4.26 (2 H, q, J = 7.4 Hz), 2.53 (2 H, t, J = 7.4 Hz), 1.61-1.29 (8 H, m), 1.35 (3 H, t, J = 7.4 Hz), 0.92 (3 H, t, J = 6.1 Hz). ¹³C NMR (75 MHz, CDCl₃): δ = 168.1 (C), 138.9 (CH), 138.1 (C), 136.5 (C), 132.5 (CH), 128.7 (CH), 128.5 (CH), 126.9 (CH), 123.7 (CH), 60.4 (CH₂), 31.5 (CH₂), 29.7 (CH₂), 29.1 (CH₂), 27.0 (CH₂), 22.5 (CH₂), 14.2 (CH₃), 14.0 (CH₃). HRMS: m/z calcd for C₁₉H₂₆O₂: 286.1933; found: 286.1904. IR (neat): 2958, 2871, 1461, 1375 cm^-1

12b Concellón JM. Bernad PL. Rodríguez-Solla H. Angew. Chem. Int. Ed.  2001,  40:  3897 

13 Concellón JM. Concellón C. Méjica C. J. Org. Chem.  2005,  70:  6111 ; see also ref. 2, 3, 12

Manganese(II) enolates and related species have been proposed as intermediates in other manganese-promoted transformations. See:

14a Dessole G. Bernardi L. Bonini BF. Capitò E. Fochi M. Herrera RP. Ricci A. Cahiez G. J. Org. Chem.  2004,  69:  8525 

14b Tang J. Shinokubo H. Oshima K. Tetrahedron  1999,  55:  1893 

14c Cahiez G. Figadère B. Cléry P. Tetrahedron Lett.  1994,  35:  6295 

15 Similar transition state models have been proposed to explain the selectivity in other Mn(II)-promoted reactions: Oshima K. J. Organomet. Chem.  1999,  575:  1