- Benzylic Hydroperoxidation via Visible-Light-Induced Csp3-H Activation
-
A highly efficient benzylic hydroperoxidation has been realized through a visible-light-induced Csp3-H activation. We believe that this reaction undergoes a direct HAT mechanism catalyzed by eosin Y. This approach features the use of a metal-free catalyst (eosin Y), an energy-economical light source (blue LED), and a sustainable oxidant (molecular oxygen). Primary, secondary, and tertiary hydroperoxides as well as silyl, benzyl, and acyl peroxides were successfully prepared with good yields and excellent functional group compatibility.
- Inoa, Joan,Patel, Mansi,Dominici, Grecia,Eldabagh, Reem,Patel, Anjali,Lee, John,Xing, Yalan
-
p. 6181 - 6187
(2020/05/22)
-
- Preparation method of arylethyl hydrogen peroxide (by machine translation)
-
The invention discloses a preparation method of arylethyl hydrogen peroxide. The aromatic ethane is used as a starting material, the raw materials are easy to obtain; the product obtained by the method is wide in application, and can be conveniently converted into aryl ethanone. In addition, the method disclosed by the invention is carried out in illumination air, is mild in reaction condition, high in target product yield, simple, and suitable for industrial production, and the reaction operation and the post-treatment process are simple. (by machine translation)
- -
-
Paragraph 0024
(2019/09/05)
-
- Selective catalytic aerobic oxidation of substituted ethylbenzenes under mild conditions
-
Ethylbenzene is oxidized to the corresponding hydroperoxide (PEHP) with high selectivity, under mild conditions, by means of a metal-free catalytic system consisting of an aldehyde and N-hydroxyphthalimide (NHPI). The process occurs via a free radical mechanism by in situ generation of the phthalimido-N-oxyl (PINO) radical. The protocol is applied with success on a wide range of substituted ethylbenzenes (ETBs). The competitive experiments carried out on few couples of ETBs revealed a marked polar effect, this proving the key role that PINO plays as real hydrogen abstracting species, at least at low conversion. At higher conversion, the formation of highly reactive OH radicals from PEHP reduces the differences in the reactivity of selected couples of ETBs. The study of the reaction mechanism, including the investigation on aldehyde and catalyst percentage amounts, and temperature and concentration effects, allows to achieve the final PEHPs products with good yields.
- Melone, Lucio,Prosperini, Simona,Gambarotti, Cristian,Pastori, Nadia,Recupero, Francesco,Punta, Carlo
-
experimental part
p. 155 - 160
(2012/03/09)
-
- 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
-
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.
- Zilbeyaz, Kani,Kilic, Hamdullah,Sisecioglu, Melda,Ozdemir, Hasan,Guengoer, Azize Alayli
-
experimental part
p. 594 - 601
(2012/08/13)
-
- Direct hydroperoxygenation of conjugated olefins catalyzed by cobalt(II) porphyrin
-
A novel and direct synthesis of hydroperoxy compounds from various types of conjugated olefins was established via cobalt(II) porphyrin-catalyzed hydroperoxygenation. The reaction of α,β,γ,δ-unsaturated carbonyl compounds, acrylic esters, α-substituted acrylic esters and styrene derivatives with molecular oxygen and triethylsilane in the presence of a catalytic amount of cobalt(II) porphyrin proceeded rapidly to give the corresponding hydroperoxygenated compounds in high or moderate yields.
- Sugamoto, Kazuhiro,Matsushita, Yoh-Ichi,Matsui, Takanao
-
p. 3989 - 3998
(2007/10/03)
-
- Cobalt(II) Porphyrin-Catalyzed Oxidation of Olefins to Ketones with Molecular Oxygen and Triethylsilane in 2-Propanol
-
An efficient conversion of olefins to ketones was achieved by the use of molecular oxygen and triethylsilane in the presence of a catalytic amount of cobalt(II) complex of porphyrin.The oxidation was accelerated remarkably in alcohols and had chomoselectivity for conjugated olefins.
- Matsushita, Yoh-ichi,Matsui, Takanao,Sugamoto, Kazuhiro
-
p. 1381 - 1384
(2007/10/02)
-