10.1002/anie.201713189
Angewandte Chemie International Edition
COMMUNICATION
Scheme 2. Biocatalytic enantioselective oxidation of (S)-1-phenylethanethiols 1a-h with HMFO-variants.
column chromatography on silica gel and the ee of (R)-thiols was
measured on chiral HPLC after derivatization (see SI).
Table 2. Enantioselective oxidation of 1-phenylethanethiol derivatives by
Val465Ser HMFO variant.[a]
rac-Substrate
Conversion
[%][b]
ees (R) [%][c]
E[d]
Acknowledgements
1a
1b
1c
1d
1e
1f
48
91
>200
45
Funding by the Austrian Science Fund (FWF) within the DK
Molecular Enzymology (project W901) and the Austrian BMWFW,
BMVIT, SFG, Standortagentur Tirol, Government of Lower
Austria and ZIT through the Austrian FFG-COMET-Funding
Program is gratefully acknowledged. The authors wish to thank
Doris Loidolt for technical assistance and Philipp Neu and Walter
Keller for HR-MS and CD-measurements.
50
88
47
87
>200
>200
150
44 (50)[e]
30 (45)[e]
50
78 (>97)[e]
42 (80)[e]
>97
>200
>200
>200
Keywords: alcohol oxidase • biocatalysis • enzyme engineering
• kinetic resolution • sec-thiol oxidation
1g
1h
49
>97
44 (49)e
78 (93)e
[1]
a) H. Gröger, Y. Asano, in Enzyme Catalysis in Organic Synthesis,
Wiley-VCH Verlag GmbH & Co. KGaA, 2012, pp. 1-42; b) R. Kourist,
Angew. Chem. 2015, 127, 12729-12729; c) R. N. Patel, Bioorg. Med.
Chem. 2017, DOI: 10.1016/j.bmc.2017.05.023; d) A. Robic, C.
Ullmann, P. Auffray, C. Persillon, J. Martin, OCL 2017, 24, D404; e)
M. D. Truppo, ACS Med. Chem. Lett., 2017, 8, 476–480.
a) K. Pachamuthu, R. R. Schmidt, Chem. Rev. 2006, 106, 160-187;
b) E. A. Ilardi, E. Vitaku, J. T. Njardarson, J. Med. Chem. 2014, 57,
2832-2842; c) Organosulfur Chemistry in Asymmetric Synthesis,
Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany, 2008;
d) J. Clayden, P. MacLellan, Beilstein J. Org. Chem. 2011, 7, 582-
595; e) T. Nagao, M. Sato, H. Nakajima, A. Kiyomoto, Chem. Pharm.
Bull. 1973, 21, 92–97; f) B. Xu, S.-F. Zhu, Z.-C. Zhang, Z.-X. Yu, Y.
Ma, Q.-L. Zhou, Chem. Sci. 2014, 5, 1442-1448.
[a] Reactions were performed in phosphate buffer (100 mM, pH 7.0)
containing isopropanol (1% v/v), DTT (50 mM), 5 mM substrate, and
Val465Ser HMFO variant (3.5 µM), at 30 °C for 24 h in air-saturated
solutions. [b] Conversion was measured by GC-MS after extraction with
dichloromethane. [c] Enantiomeric excess of the (R)-enantiomer was
measured by HPLC after derivatization. [d]E-value determined from eeS and
conversion.[25] [e] double concentration of HMFO variant (7 µM).
[2]
ted by molecular modeling and confirmed by crystal structure
analysis. This method provides a broadly applicable tool for the
preparation of nonracemic sec-thiol building blocks.
[3]
S. Diosdado, J. Etxabe, J. Izquierdo, A. Landa, A. Mielgo, I. Olaizola,
R. López, C. Palomo, Angew. Chem. Int. Ed. 2013, 52, 11846-
11851.
General Procedure for the Kinetic Resolution
of Thiols
[4]
[5]
[6]
[7]
M. R. Monaco, S. Prévost, B. List, J. Am. Chem. Soc. 2014, 136,
16982-16985.
A. Peschiulli, B. Procuranti, C. J. O' Connor, S. J. Connon, Nat.
Chem. 2010, 2, 380.
G. Fronza, C. Fuganti, P. Grasselli, G. Pedrocchi-Fantoni, S. Servi,
Pure Appl. Chem. 2009, 64, 1099-1101.
a) N. Öhrner, C. Orrenius, A. Mattson, T. Norin, K. Hult, Enzyme
Microb. Technol. 1996, 19, 328-331; b) D. Bianchi, P. Cesti, J. Org.
Chem. 1990, 55, 5657–5659.
a) W. P. Dijkman, G. de Gonzalo, A. Mattevi, M. W. Fraaije, Appl.
Microbiol. Biotechnol. 2013, 97, 5177-5188; b) M. Pickl, M. Fuchs,
S. M. Glueck, K. Faber, Appl. Microbiol. Biotechnol. 2015, 99, 6617-
6642.
Purified HMFO variants (3.5 µM) and DTT (50 mM) were
dissolved in sodium phosphate buffer (500 µL, pH 7.0, 100 mM)
containing isopropanol (1% v/v). Then substrate (1a-h) was
added (5 mM). The vials were shaken at 30 °C with 750 rpm for
24 h in a horizontal position on a Heidolph Titramax 1000 plate
shaker. The reaction was stopped by extraction with
dichloromethane (2 x 0.5 mL). The combined organic phases
were dried over anhydrous Na2SO4 and the conversion was
determined on GC-MS. Ketone and thiol were separated by
[8]
[9]
T. A. Ewing, W. P. Dijkman, J. M. Vervoort, M. W. Fraaije, W. J. H.
van Berkel, Angew. Chem. Int. Ed. 2014, 53, 13206-13209.
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