Synlett 2003(7): 1007-1011
DOI: 10.1055/s-2003-39301
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Memory of Chirality in the Enantioselective Synthesis of β-Lactams Derived from Amino Acids. Influence of the Reaction Conditions

Mª Angeles Bonachea, Guillermo Gerona-Navarroa, Mercedes Martín-Martíneza, Mª Teresa García-Lópeza, Pilar Lópezb, Carlos Cativielab, Rosario González-Muñiz*a
a Instituto de Química Médica (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
e-Mail: iqmg313@iqm.csic.es;
b Departamento de Química Orgánica, ICMA, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
Further Information

Publication History

Received 26 February 2003
Publication Date:
20 May 2003 (online)

Abstract

The asymmetric induction observed during cyclisation of N-benzyl-N-chloroacetyl-l-Phe derivatives to the corresponding S-enriched 2-azetidinones, ascribed to chirality memory, can be controlled by the appropriate choice of the base and solvent. Using the organic base BTPP, the ee values obtained in different solvents showed a good correlation with the AN solvent parameter, except for NMP. It seems that a combination of the solvent properties, rather than individual parameters, and the presence of enolate aggregates are decisive for final enantiomer distribution.

    References

  • 1 Fuji K. Kawabata T. Chem.-Eur. J.  1998,  4:  373 
  • For examples of memory of chirality through enolate intermediates see:
  • 2a Kawabata T. Yahiro K. Fuji K. J. Am. Chem. Soc.  1991,  113:  9694 
  • 2b Kawabata T. Wirth T. Yahiro K. Suzuki H. Fuji K. J. Am. Chem. Soc.  1994,  116:  10809 
  • 2c Brewster AG. Frampton CS. Jayatissa J. Mitchell MB. Stoodley RJ. Vohra S. Chem. Commun.  1998,  299 
  • 2d Betts MJ. Pritchard RG. Schofield A. Stoodley RJ. Vohra S. J. Chem. Soc., Perkin Trans. 1  1999,  1067 
  • 2e Kawabata T. Suzuki H. Nagae Y. Fuji K. Angew. Chem. Int. Ed.  2000,  39:  2155 
  • 2f Kawabata T. Chen J. Suzuki H. Nagae Y. Kinoshita T. Chancharunee S. Fuji K. Org. Lett.  2000,  2:  3883 
  • 2g Brewster AG. Jayatissa J. Mitchell MB. Schofield A. Stoodley RJ. Tetrahedron Lett.  2002,  43:  3919 
  • On the chirality memory through carbenium ion chemistry:
  • 3a Matsumura Y. Shirakawa Y. Satoh Y. Umino M. Tanaka T. Maki T. Onomura O. Org. Lett.  2000,  2:  1689 
  • 3b Wanyoike GN. Onomura O. Maki T. Matsumura Y. Org. Lett.  2002,  4:  1875 
  • Radicals as reactive intermediates in memory of chirality processes:
  • 4a Sauer S. Schumacher A. Barbosa F. Giese B. Tetrahedron Lett.  1998,  39:  3685 
  • 4b Giese B. Wettstein P. Stähelin C. Barbosa F. Neuburger M. Zehnder M. Wessig P. Angew. Chem. Int. Ed.  1999,  38:  2586 
  • 4c Buckmelter AJ. Kim AI. Rychnovsky SD. J. Am. Chem. Soc.  2000,  122:  9386 
  • 4d Griesbeck AG. Kramer W. Lex J. Angew. Chem. Int. Ed.  2001,  40:  577 
  • 4e Griesbeck AG. Kramer W. Bartoschek A. Schmickler H. Org. Lett.  2001,  3:  537 
  • 4f Griesbeck AG. Kramer W. Lex J. Synthesis  2001,  1159 
  • 5 Gerona-Navarro G. Bonache MA. Herranz R. García-López MT. González-Muñiz R. J. Org. Chem.  2001,  66:  3538 
  • 6 Oliveros L. López P. Minguillón C. Franco P. J. Liq. Chromatogr.  1995,  18:  1521 
  • 10a Schwesinger R. Willaredt J. Schlemper H. Keller M. Schmitt D. Fritz H. Chem. Ber.  1994,  127:  2435 
  • 10b O’Donnell MJ. Delgado F. Dominguez E. de Blas J. Scott WL. Tetrahedron: Asymmetry  2001,  12:  821 
  • 11 Attempts to cyclize N-benzyl-N-chloroacetyl-l-Phe-O-t-Bu with DMAP resulted in the nucleophilic attack of the reactive to the chloroacetyl derivative (compound 4, 90%, Figure 2), as previously found for the cyclization of Trp analogues with DBU, see: Gerona-Navarro G. Bonache MA. Herranz R. García-López MT. González-Muñiz R. Synlett  2000,  1249 .Selected data for compound 4: HPLC: t R = 10.74 min [50:50, H2O/MeCN (0.05%TFA)]. 1H NMR (300 MHz, CDCl3): major rotamer δ = 8.09 (d, 2 H, J = 7.8 Hz, pyridine), 7.32-7.12 (m, 10 H, Ph), 6.68 (d, 2 H, J = 7.8 Hz, pyridine), 5.46 (d, 1 H, J = 16.8 Hz, CH2N+), 5.33 (d, 1 H, J = 16.8 Hz, CH2N+), 4.72 (d, 1 H, J = 17.2 Hz, N-CH2), 4.39 (dd, 1 H, J = 8.8, 6.2 Hz, α-H), 4.25 (d, 1 H, J = 17.2 Hz, N-CH2), 3.25 (dd, 1 H, J = 14.9, 6.2 Hz, β-H), 3.17 (s, 6 H, NMe2), 3.07 (dd, 1 H, J = 14.9, 8.8 Hz, β-H), 1.31 (s, 9 H, t-Bu). 13C NMR (75 MHz, CDCl3): major rotamer δ = 168.29 (COO), 166.07 (CON), 156.34 (4-C, pyridine), 143.68 (2-C, 6-C, pyridine), 137.35, 135.32, 129.29, 128.91, 128.86, 127.91, 127.59, 126,79 (Ph), 107.14 (3-C, 4-C, pyridine), 82.22 (C, t-Bu), 63.09 (α-C), 58.71 (CH2N+), 51.41 (N-CH2), 40.48 (CH3N), 35.53 (β-C), 27.92 (CH3, t-Bu). MS (ES, positive mode): 475.6 (M+ + 1)
  • 13 These results are atypical with respect to other alkylation reactions for which the use of polar solvents, like MeCN, resulted in almost racemic products: Belokon YN. Kochetkov KA. Churkina TD. Ikonnikov NS. Chesnokov AA. Larionov OV. Singh I. Parmar VS. Vyskocil S. Kagan HB. J. Org. Chem.  2000,  65:  7041 
  • 14a Taft RW. Kamlet MJ. J. Am. Chem. Soc.  1976,  98:  2886 
  • 14b Kamlet MJ. Abboud JL. Taft RW. J. Am. Chem. Soc.  1977,  99:  6027 
  • 16a Taft RW. Pienta NJ. Kamlet MJ. Arnett EM. J. Org. Chem.  1981,  46:  661 
  • 16b Malavolta L. Oliveira E. Cilli EM. Nakaie CR. Tetrahedron  2002,  58:  4383 
  • It has been described that the enantioselectivity of the alkylation of Phe derivatives can be controlled by regulating the aggregate structure of chiral enolate intermediates:
  • 18a Kawabata T. Kawakami S. Fuji K. Tetrahedron Lett.  2002,  43:  1465 
  • 18b Kawabata T. Kawakami S. Shimada S. Fuji K. Tetrahedron  2003,  59:  965 
  • 19a Henderson KW. Dorigo AE. Liu Q.-Y. Williard PG. von Ragué Scheyer P. Bernstein PR. J. Am. Chem. Soc.  1996,  118:  1339 
  • 19b Asensio G. Alemán PA. Domingo LR. Medio-Simón M. Tetrahedron Lett  1998,  39:  3277 
  • 20 No memeory of chriality was observed in the photochmically-induced cyclization of phenylglyoxylamide to 3-hydroxy-β-lactams: Griesbeck AG. Heckroth H. Synlett  2002,  131 
7

Column OL-389. Eluent: hexane/acetone (96:4). Flow rate: 1.5 mL/min. UV detection at 220 nm. Isomer 2a: t R = 7.77 min. Isomer 2b: t R = 9.07 min.

8

A general procedure was as follows: Compound 1 (83 mg, 0.19 mmol) was dissolved in the corresponding solvent (0.7 mL) and treated, at r.t. and under Ar atmosphere, with the appropriate base (0.28 mmol). The reaction was monitored by TLC until complete disappearance of the starting material. The solution was evaporated, redissolved in EtOAc, washed with H2O, and dried over Na2SO4. After evaporation, the resulting residue was purified on a silica gel column using a gradient from 20 to 30% of EtOAc in hexane. The obtained compound 2ab was directly evaluated by chiral HPLC, or transformed into dipeptide derivatives 3a and 3b as described (ref. [5] ). For the phase transfer reactions, 3 equiv of NaOH and KOH, and 10 equiv of CsOH were respectively used.

9

BTPP: tert-Butylimino-tri(pyrrolidino)phosphorane. BEMP: 2-tert-Butylimino-2-diethylamino-1,3-dimethylperhydro1,3,2-diazaphosphorine.

12

Reaction of chloroacetyl derivative 1 with LHMDS afforded pyrrolidinone 5, which was characterized as its methoxy derivative 6 after treatment with diazomethane. The formation of compound 5 could be attributed to the initial generation of the amide enolate and a Dieckmann-type condensation of this enolate with the ester group, followed by enolisation of the resulting ketone (Figure [3] ).
Selected data for compound 6: 1H NMR (300 MHz, CDCl3): δ = 7.26 (m, 3 H, Ph), 7.05 (m, 2 H, Ph), 7.00 (d, 2 H, J = 8.6 Hz, Pmb), 6.80 (d, 2 H, J = 8.6 Hz, Pmb), 5.18 (d, 1 H, J = 15.1 Hz, 1-CH2), 4.16 (s, 3 H, OMe), 3.93 (dd, 1 H, J = 5.4, 4.1 Hz, 5-H), 3.83 (d, 1 H, J = 15.1 Hz, 1-CH2), 3.78 (s, 3 H, OMe), 3.13 (dd, 1 H, J = 14.3, 4.1 Hz, 5-CH2), 2.89 (dd, 1 H, J = 14.3, 5.4 Hz, 5-CH2). 13C NMR (75 MHz, CDCl3): δ = 167.4 (2-C), 164.22 (4-C), 159.07, 134.95, 130.05, 129.45, 129.04, 128.74, 127.32, 114.03 (Ar), 97.91 (3-C), 59.05 (OMe), 58.65 (5-C), 55.21 (OMe), 43.88
(5-CH2), 35.47 (1-CH2). MS (ES, positive mode): 358.2
(M+ + 1).

15

NMP was not included because really poor correlations were found. To the best of our knowledge, the AN value for 2-butanone has not been described.

17

Among all the solvents tested here, NMP has not only the highest donor number (DN) but also the biggest difference between AN and DN parameters. DN is a reasonably good measure of the ability of the solvent to serve as an electron-pair donor to solutes when oxygen bases are considered.