Epoxidation of propene

Many of the reactions we ve already encountered can yield a chiral product from an achi ral starting material Epoxidation of propene for example creates a chirality center by adding oxygen to the double bond... 

Figure 7 7 shows why equal amounts of (R) and (5) 1 2 epoxypropane are formed m the epoxidation of propene There is no difference between the top face of the dou ble bond and the bottom face Peroxyacetic acid can transfer oxygen to either face with equal facility the rates of formation of the R and S enantiomers of the product are the same and the product is racemic... 

The manufacture and uses of oxiranes are reviewed in (B-80MI50500, B-80MI50501). The industrially most important oxiranes are oxirane itself (ethylene oxide), which is made by catalyzed air-oxidation of ethylene (cf. Section 5.05.4.2.2(f)), and methyloxirane (propylene oxide), which is made by /3-elimination of hydrogen chloride from propene-derived 1-chloro-2-propanol (cf. Section 5.05.4.2.1) and by epoxidation of propene with 1-phenylethyl hydroperoxide cf. Section 5.05.4.2.2(f)) (79MI50501). 

B.S. Uphade, M. Okumura, S. Tsubota, and M. Haruta, Effect of physical mixing of CsCl with Au/Ti-MCM-41 on the gas-phase epoxidation of propene using H2 and02 Drastic depression of H2 consumption, Appl. Catal. A 190, 43-50 (2000). 

Fluidized-bed reactor Epoxidation of propene Mycobacterium cells 125... 

A. K. Sinha, S. Sedan, S. Tsubota, and M. Haruta, A three-dimensional mesoporous titanosilicate support for gold nanoparticles Vapour-phase epoxidation of propene with high conversion, Angew. Chem. Int. Ed. 43(12), 1546-1548 (2004). 

A. Zwijnenburg, M. Saleh, M. Makkee, and J. A. Moulijn, Direct gas-phase epoxidation of propene over bimetallic Au catalysts, Catal. Today 72(1—2), 59—62 (2002). 

Epoxidation of propene and oct-l-ene was effected with tran5-Ru(0)j(TMP)/ O ll atm)/water-CH2Cl2. After some 40 turnovers in a day, the deactivated form of the complex, Ru(C0)(TMP).H20 was detected (vide infra). Use of (l-( C)-oct-l-ene suggest that, in part at least, the carbon atom of the Ru(CO)(TMP) formed derives from the first C atom of the octene [591]. For styrene epoxidation by trans-Ru(0)2(TMP)/(LN0)/CgH (LNO=N-oxides of 2,3,5,6-tetramethylpyrazine, acridine, 2-methylquinoline and 3,6-dichloropyridazine) the mono- and bis-A-oxides of tetramethylpyrazine were the most effective co-oxidants [586]. 

The first variant works with isobutane as the hydroperoxide precursor, which is oxidized to TBHP by molecular oxygen. During the epoxidation of propene, TBHP is transformed to ferf-butanol, which is converted to methyl ferf-butyl ether. The second procedure employs ethylbenzene, which is oxidized by molecular oxygen to phenyl ethyl hydroperoxide, which transfers an oxygen to propene and so is reduced to phenylethanol. This by-product of the process is converted to styrene, a versatile bulk chemical. 

Lunsford and coworkers reported on the epoxidation of propene and cyclohexene using a molybdenum zeolite, prepared by introducing either Mo(CO)g or M0CI5 into the zeolite, which showed initial good activity and selectivity for the epoxidation reaction in the presence of The activity declined over a period of minutes, which was... 

The first evidence of the capacity of supported gold catalysts to epoxidate propene was described by Haruta et al. using dioxygen in the presence of H2 as reductant, which allows 02 activation at low temperatures [237]. Although initial selectivities by Au/Ti02 were low, promising improvements were achieved with different supports [230-232, 238-246]. One of them, TS-1, is known to be suitable for the selective epoxidation of propene with H202 [246]. For that reason, many early studies focused on its use. 

The epoxidation of propene is analogous to that of ethylene catalyzed by silver. However, the selectivity is much lower. Due to the pronounced oxidation sensitivity of the allyl CH3-group, excessive combustion occurs as a side reaction. The heterogeneous process has no practical significance, therefore, as it has to compete with a highly selective liquid phase epoxidation process. 

The epoxidation of propene with tert-butylhydroperoxide (TBHP) or ethylbenzene hydroperoxide (EBHP), for example, accounts for more than one million tons of propene oxide production on an annual basis (Fig. 4.19). 

An important commercial oxidation using f-butyl hydroperoxide is the epoxidation of propene catalyzed by molybdate compounds ... 

Ill] INELASTIC INCOHERENT NEUTRON SCATTERING IN CATALYSIS RESEARCH 111 A.6. Epoxidation of Propene... 

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