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.
catalyzes highly enantioselective epoxidation of olefins with H2O2 is described. Improvement of enantiomeric excesses is attained by the use of catalytic amounts of carboxylic acid additives. Electronic effects imposed by the ligand on the iron center are shown to synergistically cooperate with catalytic amounts of carboxylic acids in promoting efficient O-O cleavage and creating highly chemo- and
Enantioselective Synthesis of Epoxides Having a Tetrasubstituted Trifluoromethylated Carbon Center: Methylhydrazine-Induced Aerobic Epoxidation of β,β-Disubstituted Enones
unprecedented title reaction is catalyzed by a methylhydrazine/base/organocatalyst (1) system. Biologically attractive epoxides (2) having a tetrasubstituted trifluoromethylated carboncenter were obtained with excellent enantioselectivity for the first time. 18O‐labeling experiments suggest a mechanism involving the activation of molecular oxygen. MTBE=methyl tert‐butyl ether.
Stereospecific alkylation of 3,5,5-trisubstituted-4-hydroxy-1-p-tosyl-2-pyrazolines by trimethylaluminum. An efficient synthesis of 3,3,5,5-tetrasubstituted-1-pyrazolin-4-ones
作者:William H. Pirkle、Dennis J. Hoover
DOI:10.1021/jo01305a007
日期:1980.8
Rama Rao, D. Sri, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1981, vol. <B> 20, # 9, p. 786 - 789
作者:Rama Rao, D. Sri
DOI:——
日期:——
Visible-Light-Promoted Photoredox Syntheses of α,β-Epoxy Ketones from Styrenes and Benzaldehydes under Alkaline Conditions
作者:Jing Li、David Zhigang Wang
DOI:10.1021/acs.orglett.5b02629
日期:2015.11.6
A range of styrenes and benzaldehydes were smoothly combined to form alpha,beta-epoxy ketones under the synergistic actions of photocatalyst Ru(bpy)(3)Cl-2, tert-butyl hydroperoxide (t-BuOOH), cesium carbonate (Cs2CO3), and visible light irradiation. The process likely proceeds through visible-light-enabled photocatalytic generations of acyl radicals as key intermediates.