Haruo Ogawa

Liquid phase oxidation of cyclo-olefins by a PdSO4–heteropolyacid catalyst system

By a PdSO4–heteropolyacid(H3PMo6W6O40)catalyst system in the liquide phase cyclo-olefins, particularly cyclopentene and cyclohexene, are oxidized to the corresponding ketones.

Hydration of cyclohexene by alkyl‐immobilized H‐ZSM‐5 catalyst in decalin–water system

In the hydration of cyclohexene, alkylchlorosilane‐treated ZSM‐5s, which floated at the interface of the two liquids, were observed to be solid interface catalysts in a decalin–water system. The catalysts, especially cyclohexyl‐immobilized H‐ZSM‐5, show their capacity of accelerating the hydration with suppression of the formation of by‐products such as dicyclohexyl ether.

Ring-opening of 1,2-epoxyalkane with alcohols over H-ZSM-5 in liquid phase

H-ZSM-5 readily catalyzed the ring-opening of 1,2-epoxyalkane with alcohols to give alkoxy alcohols. The reaction proceeded accompanying the shape-selective properties of H-ZSM-5. The rate of the ring-opening was retarded by use of alcohols with larger numbers of carbon atoms such as hexanol. The selectivities for the substitution of nucleophile alcohols at the sterically more hindered position of the epoxide were improved to be almost higher than those under basic conditions.

Substituent effects in heterogeneous catalysis: VIII. Reactions of 2-methyl- and 2-ethylcyclohexanone with deuterium catalyzed by platinum metals

Abstract 2-Methyl and 2-ethyl derivatives of cyclohexanone were allowed to react with deuterium in tBuOD using platinum group metals as catalysts. The product alcohols and the remaining ketone were examined by mass spectrometry. Over Ru, Os, and Ir, the simple addition of two deuterium atoms to the carbonyl linkage was predominant, accompanied by little isotopic exchange. Over Pt, however, isotopic exchange was significant and over Rh and Pd quite extensive. The samples obtained over Rh and Pd were further analyzed by NMR spectroscopy to determine the loci of the incorporated deuterium atoms. Deuterium exchange over Pd was almost entirely confined to the C(2) and C(6) positions, while that over Rh was smeared beyond these positions. These results can be accounted for by assuming the intermediacy of π-absorbed π-oxaallylic species on Pd and of αβ-diadsorbed species on Rh.

Influence of solvents on hydration of 1,2-epoxyhexane overH-ZSM-5-C18 catalyst

The influence of solvents such as benzene, toluene,m-xylene, and neighbours on the hydration of 1,2-epoxyhexane caused by the pore ofH-ZSM-5-C18 catalyst was studied by measurement of the reaction rate. The largest retardation of the hydration was observed usingm-xylene as solvent. Any other solvents did not show so large a retardation as that ofm-xylene. By taking advantage of the retardation withm-xylene the effect of the pores of various types of zeolites on the rate could be dynamically demonstrated.

Substituent effects in heterogeneous catalysis: II. Deuteration of 2-methylcyclohexanone over the platinum group metals

Abstract The catalytic reactions between 2-methylcyclohexanone and deuterium on platinum group metals were studied by means of mass and NMR spectrometry. Over Ru, Os, and Ir, only reduction to the corresponding alcohols occurred, brought about by simple addition of two deuterium atoms to the carbonyl bond. In contrast, over Rh and Pd, significant isotopic exchange at the C 2 and C 6 positions also occurred. The results over Pt were intermediate between these two groups. The axial and equatorial deuterium contents at each carbon position were also estimated for Rh and Pd. One characteristic feature was that, over Rh, the axial D content at C 6 is greater than that at C 2 and the reverse is true over Pd. A reaction mechanism for reduction and exchange is presented and discussed.

Selective formation of glycylglycine by dehydration of glycine adsorbed on silica gel

Silica gel promotes the selective dehydration of glycine to form intermediate glycylglycine, with inhibition of the formation of stable glycine anhydride and polymer products. IR measurements indicate that glycine adsorbed on silica gel results in the formation of neutral species having CO and NH2 groups. The species is considered to stimulate dehydration, leading to the reported selective dehydration. Copyright

Gaseous NO as the source of nitrosyl ligand in carbonyl clusters. X-Ray structure of [Ru6C(CO)14(C3H5)(NO)] and fluxionality of the µ-allyl ligand

Nitric oxide gas reacts with an anionic carbonyl cluster of ruthenium, [Ru3(CO)9C2R]–(R = But or SiMe3), to give the neutral nitrosyl complex [Ru3(CO)9C2R(NO)], while the reactions with the dianionic carbide cluster [Ru6C(CO)16]2– and its monoanionic µ–η3-allyl derivative, [Ru6C(CO)15(C3H5)]–, give good yields of monoanionic [Ru6C(CO)15(NO)]– and neutral [Ru6C(CO)14(C3H5)(NO)] complexes, respectively; the latter complex is unique in exhibiting fluxionality of the µ-allyl ligand.

Facile synthesis of ε-caprolactam by cyclodehydration of 6-aminocaproic acid on adsorbents

Iµ-Caprolactam is readily synthesized by refluxing a suspension of 6-aminocaproic acid adsorbed on zeolite, silica gel, or alumina in toluene.

Octadecyl immobilized H-ZSM-5-catalyzed ring-openings of epoxides with water in liquid phase accompanying shape-selective property

The octadecyltrichlorosilane-treated ZSM-5 catalyst H-ZSM-5-C18 exhibited high activity in the ring-opening reaction of epoxides in a toluene-water solvent. The shape-selective property of H-ZSM-5-C18 in the liquid phase has also been observed by comparing the reaction rates with those over octadecyltrichlorosilane treated SiO2-Al2O3.