Chiral azo compounds: Enantioselective synthesis and transformations into β-amino alcohols and α-amino acids with a quaternary stereocenter

Tetrahedron Letters

Volumn 52, Issue 6, 2011, Pages 655-657

  Dietz, Friedrich R ^a   Prechter, Agnes ^a   Gröger, Harald ^a   Heinrich, Markus R ^a  

^a UNIVERSITY OF ERLANGEN NUREMBERG   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

ALCOHOL DERIVATIVE; ALPHA AMINO ACID; AZO COMPOUND;

AMINATION; ARTICLE; BIOTRANSFORMATION; CARBOAMINATION; CHEMICAL REACTION; CHIRALITY; ENANTIOMER; ENANTIOSELECTIVITY; OXIDATION; SYNTHESIS;

EID: 79251597363     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2010.11.137     Document Type: Article

References (23)

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16. 1H NMR to determine the conversion of the reactant 7. For the enantiomeric excess, the remaining acetate 7 and the alcohol 2 were first separated by column chromatography on silica gel (hexane/ethyl acetate) and then analyzed by chiral HPLC.
17. For recently reported BACE-1 inhibitors with amino alcohols 3 as substructure, see: H.A. Rajapakse, P.G. Nantermet, H.G. Selnick, J.C. Barrow, G.B. McGaughey, S. Munshi, S.R. Lindsley, M.B. Young, P.L. Ngo, M.K. Holloway, M.-T. Lai, A.S. Espeseth, X.-P. Shi, D. Colussi, B. Pietrak, M.-C. Crouthamel, K. Tugusheva, Q. Huang, M. Xu, A.J. Simon, L. Kuo, D.J. Hazuda, S. Graham, and J.P. Vacca Bioorg. Med. Chem. Lett. 20 2010 1885 1889
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19. Even enzymatic approaches as the state of the art in industrial amino acid production are very rare for the synthesis of α-methylated amino acids. An exception is the efficient amidase-catalyzed resolution of racemic amino acid amides, see: B. Schulze, and E. de Vroom K. Drauz, H. Waldmann, 2nd ed. Enzyme Catalysis in Organic Synthesis Vol. 2 2002 Wiley-VCH Weinheim chapter 12.2.3
20. An attractive organocatalytic approach toward enantiomerically enriched α-methylated amino acids is the phase-transfer-catalyzed double alkylation of glycinates or monoalkylation of alaninates, which, however, requires the use of totally protected amino acids as starting materials and the cleavage of these protecting groups at a later stage. For this approach, see: T. Hashimoto, and K. Maruoka Chem. Rev. 107 2007 5656 5682
21. 4-mediated reduction was carried out according to the following literature procedure: C.W. Grote, D.J. Kim, and H. Rapoport J. Org. Chem. 60 1995 6987 6997
22. The oxidation was carried out according to the following literature procedure: Alsters, P.; Bouttemy, S.; Schmieder-van de Vondervoort, E.; Padron Carillo, J. M. PCT WO 01/53240A1, 2001.
23. The enantiomeric excess of 4a was determined after its conversion to the ethyl ester derivative 9a (see Supplementary data).