Stereoselective synthesis of optically active 1-benzyl-4,5,6,7-tetrahydro-6,6-dimethyl-4-oxo-1H-indol-7-yl acetate and 1-benzyl-6,7-dihydro-7-hydroxy-6,6-dimethyl-1H-indol-4(5H)-one through lipase-catalyzed esterification and transesterification processes

Caliskan Z. Z., Ersez M.

JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC, cilt.111, ss.64-70, 2015 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 111
  • Basım Tarihi: 2015
  • Doi Numarası: 10.1016/j.molcatb.2014.10.015
  • Dergi Adı: JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.64-70
  • Anahtar Kelimeler: Indole, Enzyme-mediated hydrolysis, Transesterification, EFFICIENT CHEMOENZYMATIC ROUTE, MANGANIC ACETATE, FACILE SYNTHESIS, ALPHA'-ACETOXY, GAMMA-LACTONES, CYCLIC ENONES, OXIDATION, ENANTIOMERS, RESOLUTION, OLEFINS
  • İstanbul Üniversitesi Adresli: Hayır

Özet

The enantioselective synthesis of 1-benzyl-4,5,6,7-tetrahydro-6,6-dimethyl-4-oxo-1H-indol-7-yl acetate (4) and 1-benzyl-6,7-dihydro-7-hydroxy-6,6-dimethyl-1H-indol-4(5H)-one (5), which are important intermediates in pharmaceutical industry, was carried out for the first time, both by enzyme-mediated hydrolysis and transesterification reactions with high enantiomeric excesses in the presence of various lipases. In either case S enantiomer of (5) was obtained with high enantiomeric excesses at low rate of conversion and E value. However, R enantiomer of (5) was also obtained by transesterification reaction with high optical purity. In the transesterification reaction of (rac-5a) with several lipases in different solvent systems in the peresence of DMAP as an additive and vinyl acetate, E value of the reaction were raised for some enzyme and solvent combination (THF-MJL with >99% ee and E value: 41; for acetonitrile-MJL with 91% ee and E value: 51; for acetonitrile-Amano with 99% ee, E value: 68) showed R-(5) selectivity. Furthermore the conversion value was also increased. The best conversion of the transesterification reaction was 39% with DMSO-HPL showed 73% ee and E value: 15 for R-(5) selectivity and 47% for S-(4) selectivity. The two procedures can therefore be considered as complementary with respect to the final composition. (C) 2014 Published by Elsevier B.V.