- A H2O2/HBr system-several directions but one choice: oxidation-bromination of secondary alcohols into mono- or dibromo ketones
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In this work we found that a H2O2-HBr(aq) system allows synthesis of α-monobromo ketones and α,α′-dibromo ketones from aliphatic and secondary benzylic alcohols with yields up to 91%. It is possible to selectively direct the process toward the formation of mono- or dibromo ketones by varying the amount of hydrogen peroxide and hydrobromic acid. The convenience of application, simple equipment, multifaceted reactivity, and compliance with green chemistry principles make the application of the H2O2-HBr(aq) system very attractive in laboratories and industry. The proposed oxidation-bromination process is selective in spite of known properties of ketones to be oxidized by the Baeyer-Villiger reaction or peroxidated with the formation of compounds with the O-O moiety in the presence of hydrogen peroxide and Bronsted acids.
- Nikishin, Gennady I.,Kapustina, Nadezhda I.,Sokova, Liubov L.,Bityukov, Oleg V.,Terent'ev, Alexander O.
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p. 28632 - 28636
(2018/08/31)
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- Fast oxidation of secondary alcohols by the bromate-bromide system using cyclic microwave heating in acidic water
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We report an improved, gentle, cyclic microwave activation technique for the oxidation of secondary alcohols using nonhazardous hypobromous acid (BrOH) as the reagent in acidic water. Several aliphatic and aromatic secondary alcohols were successfully oxidized to the corresponding ketones using this technique in high yields and with only minor amounts of side products.
- P??kk?nen, Sanna,Pursiainen, Jouni,Lajunen, Marja
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scheme or table
p. 6695 - 6699
(2011/02/23)
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- Oxidation of primary and secondary alkanols with the CeIII-LiBr- H2O2 system
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Action of a novel oxidation system, Ce(NO3)3? 6H2O (cat.)-LiBr (cat.)-H2O2 (stoichiometric oxidant) on primary aliphatic C6-C9 alcohols gives selectively esters, whereas secondary aliphatic C5-C9 alcohols are converted into ketones. Selectivity of these transformations is provided by slow addition of H2O2 to the other reactants.
- Kapustina,Sokova,Nikishin
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experimental part
p. 1284 - 1288
(2011/02/23)
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- 4,3-ADDITIONS TO α,β-UNSATURATED KETONES VIA η2 C=C BINDING TO A RUTHENIUM COMPLEX.
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The *Ru(CO)2>+ fragment (Cp* = η5-C5Me5) binds α,β-unsaturated ketones in an η2-C=C fashion.The resulting complex is subject to attack by H- at the 4-position, leaving the ruthenium bound to the substrate at the 3-position.The Ru-C bond, formed in this way, can be cleaved to give a variety of 4,3-addition products.
- Tanke, Robin S.,Crabtree, Robert H.
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p. 6737 - 6740
(2007/10/02)
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