A Practical Method for Epoxidation of Terminal Olefins with 30% Hydrogen Peroxide under Halide-Free Conditions

Satō, Kazuhiko; Aoki, Masayoshi; Ogawa, Masami; Hashimoto, Tadashi; Noyori, Ryoji

doi:10.1021/jo961287e

Cited by 309 publications

(121 citation statements)

References 19 publications

Supporting

Mentioning

119

Contrasting

Order By: Relevance

“…These results, joined to those data compiled in Figure 1 (higher stability of H 2 O 2 ) demonstrate the necessity of the acetic acid for the reaction under study [19][20][21][22].…”

Section: Page 18 Of 25supporting

confidence: 75%

See 1 more Smart Citation

Influence of peroxometallic intermediaries present on polyoxometalates nanoparticles surface on the adipic acid synthesis

Alcañiz-Monge

Trautwein

Garcı́a-Garcı́a

2014

Journal of Molecular Catalysis A: Chemical

View full text Add to dashboard Cite

“…These results, joined to those data compiled in Figure 1 (higher stability of H 2 O 2 ) demonstrate the necessity of the acetic acid for the reaction under study [19][20][21][22].…”

Section: Page 18 Of 25supporting

confidence: 75%

“…Complementary, acetic acid was added to the reaction medium as a source of protons, which seems to be essential for the oxidation reaction based on different authors' studies [19][20][21][22].…”

Section: Methodsmentioning

confidence: 99%

Influence of peroxometallic intermediaries present on polyoxometalates nanoparticles surface on the adipic acid synthesis

Alcañiz-Monge

Trautwein

Garcı́a-Garcı́a

2014

Journal of Molecular Catalysis A: Chemical

View full text Add to dashboard Cite

“…4 This method, however, has the disadvantage of forming large amounts of carboxylic acids as by-products. Although the use of homogeneous catalytic systems based on rhenium, manganese and tungsten in combination with hydrogen peroxide has been the subject of intensive research, [5][6][7] homogeneous catalysis presents several drawbacks, in particular the recovering of the catalysts at the end of the process, warranting the search for heterogenized epoxidation systems. We wish to present herein an account of our efforts to develop heterogeneous epoxidation catalysts using different approaches for the immobilization of the active species.…”

Section: Introductionmentioning

confidence: 99%

Heterogenization of alkene epoxidation catalysts

Buffon¹,

Schuchardt²

2003

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Este trabalho descreve nosso esforço em heterogeneizar catalisadores para epoxidação. Tanto o molibdênio ancorado quanto o engaiolado pelo método de sol-gel mostraram grande seletividade, mas possuem suas atividades fortemente reduzidas. Por outro lado, silicatos de molibdênio foram muito ativos e estáveis até a formação de diols na mistura reacional. Catalisadores heterogeneizados de rênio foram menos ativos, mas permitiram o uso do peróxido de hidrogênio anidro como oxidante. Contudo, o alto custo e a dificuldade de regeneração impedem a aplicação industrial destes catalisadores. Durante estas investigações, descobrimos que a alumina sozinha é ativa para epoxidação com peróxido de hidrogênio anidro, fornecendo boas conversões para epóxidos com alta seletividade. Mais pesquisa é necessária para esclarecer a natureza dos grupos hidroxilas responsáveis pela atividade catalítica, para produzir materiais que permitem a obtenção de epóxidos com alta seletividade em condições industriais.This account describes our efforts to heterogenize epoxidation catalysts. Anchored and sol-gel entrapped molybdenum were shown to be very selective, but had a strongly reduced activity. On the other hand, molybdenum silicates were very active and stable as long as no diols were present in the reaction mixture. Heterogenized rhenium catalysts were less active but allowed the use of anhydrous hydrogen peroxide as oxidant. However, the high cost and difficult regeneration prevents the industrial use of these catalysts. During these investigations, we found that alumina alone is active in the epoxidation with anhydrous hydrogen peroxide, giving good conversions to epoxides with high selectivity. More research is needed in order to clarify the nature of the hydroxyl groups responsible for its catalytic activity and thus to produce an appropriate material which would allow the obtention of epoxides with high selectivity under industrial conditions.

show abstract

“…To eliminate this variable, trioctylmethylammonium chloride (TOMAC) was synthesised from trioctylamine and dimethylsulfate by adapting a reported procedure. 8 The appearance of TOMAC was that of a light amber coloured viscous liquid at room temperature, effectively an ionic liquid. It was immiscible in isooctane and in water, of intermediate density with respect to these two solvents, with which it therefore formed a triphasic system, placing itself between the other two.…”

mentioning

confidence: 99%

Triphasic Liquid Systems: Generation and Segregation of Catalytically Active Pd Nanoparticles in an Ammonium‐Based Catalyst‐Philic Phase.

et al. 2007

View full text Add to dashboard Cite

A triphasic liquid system fabricated from isooctane, aqueous base, and trioctylmethylammonium chloride/decanol promoted the formation of Pd-nanoparticles in the size range of 2-4 nm which remained immobilised in the onium phase, catalysed organic reactions, and could be recycled.Onium salts, that are phase transfer agents, can be used to produce and stabilize metal nanoparticles (NPs) in situ, 1,2 and to control their size, 3 starting from appropriate precursors. Reetz and coworkers 2 have amply demonstrated that nanostructured R 4 N + X 2 -stabilized metal clusters can be prepared by a variety of methods. Recently, peculiar liquid systems formed by three separate liquid phases have attracted our attention, in particular with a view towards the possible effects on catalysis. 4 The interest was stimulated by knowledge of the formation of triphasic liquid systems made by mixtures of an organic solvent such as isooctane, water, and an onium salt (ammonium or phosphonium), and their use in heterogeneously catalysed organic reactions. 5 Increases in rates and selectivities could be achieved for a number of reactions catalysed, for example, by supported metals such as Pd, Pt, and by Raney-Ni. The onium salt was preferably liquid at the reaction temperature (20-50 uC), had a strong affinity for the catalyst, and formed a separate phase. The interaction between the liquid onium salt, and the catalyst was shown to be the factor controlling the improved catalytic effect. 6 In addition, the strong affinity of the onium salt for the catalyst made it a catalyst-philic phase, that simplified the separation of products from catalysts and from byproducts once the reaction was complete. 4 We reasoned that it would be interesting to take advantage of triphasic liquid systems, to generate, immobilise, and stabilise catalytically active metal NPs, starting from precursor metal complexes. The outcome was envisaged as shown in Fig. 1.This system offers a number of potential advantages in view of process intensification: (i) the active catalytic NPs can be prepared directly in the reactor, (ii) it is easy to separate the organic products from the catalyst by decanting, (iii) the catalyst morphology can be tuned, (iv) the metal NPs are stabilized by the third phase, and (v) inorganic reagents (i.e. base) and by-products remain in the aqueous phase, not to mention that the amount of catalyst-philic phase can be as small as convenient. All these issues are the basis for cleaner, cheaper catalytic systems, 7 and characterize some of the principles of green chemistry.This communication describes how a ternary system of this kind can be constructed, and used for catalytic reactions, through five subsequent steps: the preparation of a suitable ternary liquid system, formation of the active catalytic species, screening on a model organic reaction, catalyst recovery and recycle tests, and finally the characterisation of the active catalytic species by TEM.At first, the conditions for the reproducible formation of a model triphasic system wer...

show abstract

A Practical Method for Epoxidation of Terminal Olefins with 30% Hydrogen Peroxide under Halide-Free Conditions

Cited by 309 publications

References 19 publications

Influence of peroxometallic intermediaries present on polyoxometalates nanoparticles surface on the adipic acid synthesis

Influence of peroxometallic intermediaries present on polyoxometalates nanoparticles surface on the adipic acid synthesis

Heterogenization of alkene epoxidation catalysts

Triphasic Liquid Systems: Generation and Segregation of Catalytically Active Pd Nanoparticles in an Ammonium‐Based Catalyst‐Philic Phase.

Contact Info

Product

Resources

About