The sperm whale myoglobin active site mutants (L29H/H64L and F43H/H64L Mb) have been shown to catalyze the asymmetric oxidation of sulfides and olefins. Thioanisole, ethyl phenyl sulfide, and cis-β-methylstyrene are oxidized by L29H/H64L Mb with more than 95% enantiomeric excess (% ee). On the other hand, the F43H/H64L mutant transforms trans-β-methylstyrene into the trans-epoxide with 96% ee. The
Asymmetric sulfoxidation catalyzed by a vanadium bromoperoxidase: Substrate requirements of the catalyst
作者:Malin A Andersson、Stig G Allenmark
DOI:10.1016/s0040-4020(98)00956-9
日期:1998.12
An investigation of the catalytic effect on vanadium bromoperoxidase (VBrPO, from Corallina officinalis) on the oxidation of a series of prochiral sulfides by hydrogen peroxide, revealed that substrates having a cis-positioned carboxyl group are oxidized rapidly, giving the sulfoxide in >95% e.e. The pH-rate profile shows a typical sharp sigmoidal curve, indicative of a deprotonation event at around
Stereochemisty of oxygenation of organic sulphides with pig liver microsomal FAD-containing mono-oxygenase: comparison with cytochrome P-450PB oxidations
The enantiotopic differentiating ability of piglivermicrosomalFAD-containingmono-oxygenase (EC 1.14.13.8) in the oxygenation of nine unsymmetrical sulphides has been investigated. By this enzymatic oxygenation, the sulphides are converted into the corresponding optically active sulphoxides with varying degrees of enantiomeric excess (96–12%).
Asymmetric Sulfoxidation Catalyzed by a Vanadium-Containing Bromoperoxidase
作者:Malin Andersson、Andrew Willetts、Stig Allenmark
DOI:10.1021/jo9712456
日期:1997.11.1
A vanadium-containing bromoperoxidase (VBrPO) from the alga Corallina officinalis has been shown to catalyze the stereoselective oxidation of some aromatic bicyclic sulfides to the corresponding (S)-sulfoxides in high (up to 91%) ee. Hydrogen peroxide was found to have a large effect on the catalyzed reaction, most likely due to an inhibition of VBrPO. High optical and chemical yields were found to
We have determined the absolute configuration of the chiral sulfoxide 1-thiochroman S-oxide 1 using vibrational circular dichroism (VCD) spectroscopy. The VCD spectrum of a CCl4 Solution of 1 was analyzed using density functional theory (DFT). which predicts three stable conformations of 1. separated by <1 kcal/mol. The VCD spectrum predicted using the DFT GIAO methodology for the equilibrium mixture of the three conformations of (S)-1 is in excellent agreement with the experimental Spectrum of (+)-1. The absolute configuration of 1 is therefore (R)-(-).(S)-(divided by). (+)-1 and (-)-1 of high enantiomeric excess (e.e.) were synthesized in high yields via asymmetric oxidation of 1-thiochroman 2 using Ti(iso-PrO)(4) (R,R)-1.2-diphenylethane-1.2-diol H2O tert-butyl hydroperoxide and Ti(iso-PrO)(4) L-diethyl tartrate H2O cumene hydroperoxide, respectively. (C) 2001 Elsevier Science Ltd. All rights reserved.