78833-98-4Relevant academic research and scientific papers
Biocatalytic kinetic resolution of racemic hydroperoxides through the enantioselective reduction with free and immobilized microorganisms
Adam, Waldemar,Lukacs, Zoltan,Saha-Moeller, Chantu R.,Schreier, Peter
, p. 4887 - 4892 (2000)
A Bacillus subtilis strain, isolated from topsoil by a selective screening procedure, is effective for the biocatalytic kinetic resolution of racemic hydroperoxides. A variety of secondary aralkyl hydroperoxides have been resolved by this microorganism in
Preparation of enantiomerically pure p-substituted phenylethyl hydroperoxides by kinetic resolution and their use as enantioselective oxidants in the asymmetric Weitz-Scheffer epoxidation of E-chalcone
Zilbeyaz, Kani,Kilic, Hamdullah,Sisecioglu, Melda,Ozdemir, Hasan,Guengoer, Azize Alayli
experimental part, p. 594 - 601 (2012/08/13)
The kinetic resolution of a variety of secondary para-substituted phenylethyl hydroperoxides by Raphanus sativus L. (black radish peroxidase) in the presence of guaiacol is reported. The peroxidase enzyme recognized (R)-configured alkyl aryl hydroperoxides, which furnished optically active (S)-hydroperoxides and (R)-alcohols. Kinetic resolution of tertiary hydroperoxides by the enzyme was unsuccessful. This study also shows how the optically active p-substituted (S)-hydroperoxides obtained can be employed as enantioselective oxidants in the asymmetric Weitz-Scheffer epoxidation of E-chalcone in the presence of KF-Al2O3 as a base. In all cases, a chalcone epoxide with the (αS,βR)-configuration was obtained as the major isomer. Under the optimized reaction conditions, the enantiomeric excess of the chalcone epoxide was obtained in up to 49% in CH3CN at -40 °C.
Kinetic resolution of hydroperoxides with enantiopure phosphines: Preparation of enantioenriched tertiary hydroperoxides
Driver, Tom G.,Harris, Jason R.,Woerpel
, p. 3836 - 3837 (2008/02/13)
An efficient reductive kinetic resolution strategy capable of accessing optically active tertiary hydroperoxides is reported. Readily accessible tertiary hydroperoxides are resolved with commercially available (R)- or (S)-xylyl-PHANEPHOS with selectivity factors as large as 37. The resulting bis(phosphine oxide) can be recycled in high yields. The isolated mono(phosphine oxide) intermediate resolved hydroperoxides with the same selectivity as the parent bisphosphine. Copyright
Asymmetric synthesis with the enzyme Coprinus peroxidase: Kinetic resolution of chiral hydroperoxides and enantioselective sulfoxidation
Adam, Waldemar,Mock-Knoblauch, Cordula,Saha-Moeller, Chantu R.
, p. 4834 - 4839 (2007/10/03)
The enzyme Coprinus peroxidase (CiP) was employed for the kinetic resolution of racemic hydroperoxides 1 and the asymmetric sulfoxidation of prochiral sulfides 4. Eleven hydroperoxides 1a-k were reduced by CiP and guaiacol as reductant under conditions of kinetic resolution with enantioselectivities of up to >98% for the (S)-hydroperoxide 1 and 90% for the (R)-alcohol 2. In the absence of a reductant, the hydroperoxide 1a afforded with CiP enantiomerically enriched hydroperoxide la (ee up to 54%) and alcohol 2a (ee up to 40%), as well as ketone 3a (which is also formed simultaneously in all other reactions) and molecular oxygen. Catalase activity was established for CiP with hydrogen peroxide. When aryl alkyl sulfides 4 were used as oxygen acceptors, three products, sulfoxides 5, alcohols 2, and hydroperoxides 1, were obtained, all in enantiomerically enriched form. The highest ee value (89%) was achieved for the sulfoxide derived from naphthyl methyl sulfide (4f). Thus, CiP may be utilized for the asymmetric synthesis of optically active hydroperoxides 1, alcohols 2, and sulfoxides 5.
The titanium-catalyzed, asymmetric epoxidation of allylic alcohols with optically active hydroperoxides in the presence of achiral diol ligands
Adam, Waldemar,Korb, Marion N.
, p. 1131 - 1142 (2007/10/03)
The titanium-catalyzed, asymmetric epoxidation of dialkyl- and phenyl-substituted allylic alcohols with various enantiomerically pure hydroperoxides has been examined in the presence of achiral diol ligands. Enantioselectivities with ee values up to 50% were achieved in the oxygen transfer from (-)-(S)-1-phenylethyl 1a and (-)-(S)-1-phenylpropyl 1b hydroperoxides to 3-methyl-2-buten-1-ol 2a and geraniol 2b in the presence of the diethyl 2-hydroxy-2-hydroxymethylmalonate (DHHM) as an achiral multidentate diol ligand. The DHHM additive was ineffective in the asymmetric epoxidation of the phenyl-substituted allylic alcohols 3c-f, and only low ee values (up to 15%) were obtained. The optically active hydroperoxides (-)-(S)-1c and (-)-1d gave only moderate enantioselectivities (ee values up to 24%) with or without the achiral malonate additive DHHM. The concept of titanium-catalyzed, asymmetric epoxidation with optically active hydroperoxides as oxygen donors in the presence of multidentate diols as achiral ligands is less effective in its enantioselectivity than the Sharpless modus operandi of employing t-butyl hydroperoxide as achiral oxygen donor and the C2-symmetric tartrate as chiral auxiliary.
The Resolution of Racemic Hydroperoxides: The Preparation of Optically Pure Hydroperoxide Natural Products
Dussault, Patrick,Porter, Ned A.
, p. 6276 - 6277 (2007/10/02)
We report the resolution of unsaturated hydroperoxide enantiomers by liquid chromatography of diastereomeric derivatives.This method allows the nonenzymatic preparation of optically pure allylic or dienylic hydroperoxide natural products.
