Enantioselective Synthesis of α-Benzylalanine Using trans-3,4-Dihydro-3,4-diaryldibenzo[c,g]phenanthrene-3,4-diols

Abstract

Asymmetric benzylation of a benzophenone Schiff’s base of alanine ethyl ester was successfully conducted using trans-3,4-dihydro-3,4-diaryldibenzo[c,g]phenanthrene-3,4-diol as a chiral source.

Key words

amino acids - asymmetric synthesis - biaryls - diols - phase-transfer catalysis

References and Notes

• 1a Fesko K. Uhl M. Steinreiber J. Gruber K. Griengl H. Angew. Chem. Int. Ed.  2010,  49:  121 
• 1b Tanaka M. Chem. Pharm. Bull.  2007,  55:  349 
• 1c Venkatraman J. Shankaramma SC. Balaram P. Chem. Rev.  2001,  101:  3131 
• 1d Horikawa M. Shigeri Y. Yumoto N. Yoshikawa S. Nakajima T. Ohfune Y. Bioorg. Med. Chem. Lett.  1998,  8:  2027 
• 1e Khosla MC. Stachowiak K. Smeby RR. Bumpus FM. Piriou F. Lintner K. Fermandjian S. Proc. Natl. Acad. Sci. U.S.A.  1981,  78:  757 
• For reviews, see:
• 2a Maruoka K. Org. Process Res. Dev.  2008,  12:  679 
• 2b Nájera C. Sansano JM. Chem. Rev.  2007,  107:  4584 
• 2c Vogt H. Bräse S. Org. Biomol. Chem.  2007,  5:  406 
• 2d O’Donnell MJ. Acc. Chem. Res.  2004,  37:  506 
• 2e Ooi T. Maruoka K. Acc. Chem. Res.  2004,  37:  526 
• 3 O’Donnell MJ. Bennett WD. Wu S. J. Am. Chem. Soc.  1989,  111:  2353 
• 4 O’Donnell MJ. Wu S. Tetrahedron: Asymmetry  1992,  3:  591 
• 5a Jew S.-S. Jeong B.-S. Lee J.-H. Yoo M.-S. Lee Y.-J. Park B.-S. Kim MG. Park H.-G. J. Org. Chem.  2003,  68:  4514 
• 5b Lygo B. Crosby J. Peterson JA. Tetrahedron Lett.  1999,  40:  8671 
• For spiro ammonium salts, see:
• 6a Ooi T. Takeuchi M. Kato D. Uematsu Y. Tayama E. Sakai D. Maruoka K. J. Am. Chem. Soc.  2005,  127:  5073 
• 6b Ooi T. Tayama E. Maruoka K. Angew. Chem. Int. Ed.  2003,  42:  579 
• 6c Ooi T. Takeuchi M. Kameda M. Maruoka K. J. Am. Chem. Soc.  2000,  122:  5228 
• 6d Ooi T. Uematsu Y. Maruoka K. Tetrahedron Lett.  2004,  45:  1675 
• 6e Ooi T. Takeuchi M. Ohara D. Maruoka K. Synlett  2001,  1185 
• 6f For bisammonium salts, see: Ohshima T. Shibuguchi T. Fukuta Y. Shibasaki M. Tetrahedron  2004,  60:  7743 
• 7a Belokon YN. Kochetkov KA. Churkina TD. Ikonnikov NS. Chesnokov AA. Larionov OV. Singh I. Parmar VS. Vyskočil Š. Kagan HB. J. Org. Chem.  2000,  65:  7041 
• 7b Belokon YN. Kochetkov KA. Churkina TD. Ikonnikov NS. Vyskočil Š. Kagan HB. Tetrahedron: Asymmetry  1999,  10:  1723 
• 7c Belokon YN. Kochetkov KA. Churkina TD. Ikonnikov NS. Chesnokov AA. Larionov OV. Parmár VS. Kumar R. Kagan HB. Tetrahedron: Asymmetry  1998,  9:  851 
• 8 Casas J. Nájera C. Sansano JM. González J. Saá JM. Vega M. Tetrahedron: Asymmetry  2001,  12:  699 
• 9a Kitamura M. Shiomi K. Kitahara D. Yamamoto Y. Okauchi T. Synlett  2010,  1359 
• 9b Ohmori K. Kitamura M. Suzuki K. Angew. Chem. Int. Ed.  1999,  38:  1226 
• 10 For the related structure of various combination of TADDOLs and metals, see: Seebach D. Beck AK. Heckel A. Angew. Chem. Int. Ed.  2001,  40:  92 
• 11 Polt R. Peterson MA. DeYoung L. J. Org. Chem.  1992,  57:  5469 
• 13 The absolute configurations of product 4a were determined by comparison of the optical rotation of amino ester 6 (Figure 4) derived by hydrolysis of 4a (1 M citric acid in THF at r.t. for 15 h) with the literature data. See: Green JE. Bender DM. Jackson S. O’Donnell MJ. McCarthy JR. Org. Lett.  2009,  11:  807 
• 14 For the structure of coordinated potassium ion, see: Islam MS. Pethrick RA. Pugh D. J. Phys. Chem. A  1998,  102:  2201 

12

In an initial screening on bases (NaH, KH, CaH₂, NaOH, KOH, CsOH˙H₂O, CsCO₃, t-BuONa, t-BuOK), t-BuOK was good in terms of the yield and/or ee of the alkylated product 4.