Humicola lanuginosa lipase-catalyzed enantioselective resolution of β-hydroxy sulfides: versatile synthons for enantiopure β-hydroxy sulfoxides
摘要:
Humicola lanuginosa lipase-catalyzed acylation of beta -hydroxy sulfides provides both the (R)- and (S)-enantiomers in high enantiomeric purity. In two cases the resolved hydroxy sulfides were oxidized to give beta -hydroxy sulfoxides in > 99% e.e. The effect of substituents on enantioselectivity is discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.
only traces of the product were observed under these conditions (2 x). When primary or secondary alkyl thioethers were used instead of aromatic thioethers, lower yields and significant decreases in the enantioselectivities were obtained (2 p, 2 q, 2 r, and 2 s). In the case of tert-butyl thioether, a good enantiomeric excess of 82% was obtained, but this was accompanied by a very poor yield of 18% (2 t)
Humicola lanuginosa lipase-catalyzed acylation of beta -hydroxy sulfides provides both the (R)- and (S)-enantiomers in high enantiomeric purity. In two cases the resolved hydroxy sulfides were oxidized to give beta -hydroxy sulfoxides in > 99% e.e. The effect of substituents on enantioselectivity is discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.
Direct Synthesis of α-Sulfenylated Ketones under Electrochemical Conditions
作者:Aline A. N. de Souza、Aloisio de A. Bartolomeu、Timothy J. Brocksom、Timothy Noël、Kleber T. de Oliveira