Oxidation of Reactive Alcohols with Hydrogen Peroxide Catalyzed by Manganese Complexes
- PDF / 770,562 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 6 Downloads / 216 Views
Oxidation of Reactive Alcohols with Hydrogen Peroxide Catalyzed by Manganese Complexes Georgiy B. Shul’pin • Yuriy N. Kozlov • Lidia S. Shul’pina • Tatyana V. Strelkova Dalmo Mandelli
•
Received: 7 May 2010 / Accepted: 9 June 2010 / Published online: 26 June 2010 Springer Science+Business Media, LLC 2010
Abstract Two manganese-containing catalysts have been employed in the oxidation with hydrogen peroxide of two reactive alcohols (1-phenylethanol and glycerol): soluble catalyst [LMn(l-O)3MnL](PF6)2 (1a) and heterogenized catalyst [LMn(l-O)3MnL]2[SiW12O40] (1b) (L is 1,4,7trimethyl-1,4,7-triazacyclononane, TMTACN). Oxidation of 1-phenylethanol catalyzed by 1a in acetonitrile solution proceeds at room temperature in the presence of a small amount of oxalic acid; the turnover number attains 15,000 after 3 h. It has been proposed on the basis of the kinetic study that an oxidizing species is a manganyl species containing fragment ‘‘Mn=O’’ rather that hydroxyl radical. This species reacts competitively with the alcohol, acetonitrile and hydrogen peroxide. In the case of 1b dependences of the initial rates of acetophenone accumulation on concentration of the alcohol and amount of 1b have plateau. Both homogeneous and heterogeneous catalysts are
This is Part 12 from the series ‘‘Oxidations by the system ‘hydrogen peroxide–[Mn2L2O3]2? (L = 1,4,7-trimethyl-1,4,7triazacyclononane)–carboxylic acid’’’. For parts 1–11, see Refs. 70–80, respectively.
efficient in the oxidation of glycerol to produce dihydroxyacetone (DHA) as the main product. The oxidation catalyzed by 1a is one of the first examples of the glycerol oxidation by a catalytic homogeneous system. The yield of valuable products attained 45%. The oxidation of DHA in the absence of glycerol afforded mainly glycolic acid in yield 60% based on the starting DHA. The oxidation on 1b represents the first example of the glycerol transformation catalyzed by a heterogenized metal complex. Under certain conditions yields of products of deeper oxidation (glyceric, glycolic and hydroxypyruvic acids) are somewhat higher than the yield of dihydroxyacetone. Special experiments demonstrated that no leaching of active species occurs from catalyst 1b to the solution and that this catalyst can be re-used at least four times without substantial loss of activity. Keywords Alcohols Glycerol Heterogenized catalysts Homogeneous catalysis Manganese complexes Renewables
1 Introduction G. B. Shul’pin (&) Y. N. Kozlov Semenov Institute of Chemical Physics, Russian Academy of Sciences, ulitsa Kosygina, dom 4, Moscow 119991, Russia e-mail: [email protected]; [email protected] L. S. Shul’pina T. V. Strelkova Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, ulitsa Vavilova, dom 28, Moscow 119991, Russia D. Mandelli Faculdade de Quı´mica, Pontifı´cia Universidade Cato´lica de Campinas, Campus I, Rod. D. Pedro I, km 136, Pq. das Universidades, Campinas, SP 13086-900, Brazil e-mail: [email protected]
Oxidation of alcohols to the corresponding carb
Data Loading...
