Reductive transformation of α,β-epoxy ketones and other compounds promoted through photoinduced electron transfer processes with 1,3-dimethyl-2-phenylbenzimidazoline (DMPBI)
摘要:
Photoreactions of epoxy ketones, aromatic ketones, haloketones, and aromatic halides with 1,3-dimethyl-2-phenylbenzimidazoline (DMPBI) were studied Photoinduced single-electron transfer from DMPBI to such substrates initiates the reactions followed by radical radical rearrangement and reduction to finally give several reduced products in modest to good yields. (C) 1999 Elsevier Science Ltd. All rights reserved.
Epoxidation of 1,4-Diaroyl Ethene Derivatives in the Presence of UHP or H2O2
摘要:
Hydrogen peroxide (H2O2) or urea-hydrogen peroxide (UHP) in basic media react with carbon-carbon double bonds of 1,4-diaroyl ethenes to produce the corresponding epoxides.
Epoxidation by sodium chlorite with aldehyde-promoted chlorine dioxide formation
作者:Ashok Jangam、David E. Richardson
DOI:10.1016/j.tetlet.2010.09.102
日期:2010.12
An improved method is described for selective room temperature epoxidation of alkenes by sodium chlorite in a solvent mixture of ethanol, acetonitrile, and water buffered at pH 7. In addition, the use of aldehydes as promoters in chlorite oxidations is described for the first time. The amount of sodium chlorite, the solvent mixture, and the addition of formaldehyde as a practical promoter were optimized
Quest for Efficient Catalysts based on Zinc<i>tert</i>-Butyl Peroxides for Asymmetric Epoxidation of Enones:<i>C<sub>2</sub></i>-<i>vs C<sub>1</sub></i>-Symmetric Auxiliaries
Zinc tert‐butyl peroxide‐based catalysts for the asymmetricepoxidation of enones using tert‐butyl hydroperoxide as an oxidant have been developed. A comparative study of chiral monoanioninc N,N′‐bidentate ligands, C2‐symmetric bisoxazolinates and C1‐symmetric enaminooxazolinates, revealed excellent performance of C1‐symmetric auxiliary ligands on catalytic asymmetricepoxidation of enones (up to 96%