A New Solid‐Phase Reaction System Utilizing a Temperature‐ Responsive Catalyst: Oxidative Cyclization with Hydrogen Peroxide

Hamamoto, Hiromi; Suzuki, Yachiyo; Takahashi, Hideyo; Ikegami, Shiro

doi:10.1002/adsc.200700114

Cited by 44 publications

(28 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Synthetic methodology for the synthesis of 5 has been reported; examples are the oxidative cyclization reaction of 5-hexen-1-ol [55][56][57] using TS-1 (60°C, 6 h) [55,56] or a PNIPAAm-PW 12 O 40 3-complex (60°C, 6 h) [57] to give 90 % and 70 % yield of 5, respectively. The synthesis of 5 from 2 [58] using BuSnCl 3 as the catalyst (230°C, 3 h) has also been explored and 5 was obtained in 60 % yield.…”

Section: Two-step Synthetic Approach Viamentioning

confidence: 99%

From 5-Hydroxymethylfurfural (HMF) to Polymer Precursors: Catalyst Screening Studies on the Conversion of 1,2,6-hexanetriol to 1,6-hexanediol

et al. 2012

View full text Add to dashboard Cite

1,6-hexanediol (1) is an important polymer precursor for the polyester industry. In this paper, exploratory catalyst screening studies on the synthesis of 1 from 1,2,6-hexanetriol (2) are described via two different routes. The latter is available by a two-step procedure from 5-hydroxymethylfurfural (HMF, 3), a promising bio-based platform chemical. In the first approach, the direct catalytic hydrodeoxygenation of 2 to 1 with heterogeneous catalysts and molecular hydrogen was explored. Best results were obtained using a Rh-ReO x /SiO 2 catalyst in water (180°C, 80 bar H 2 , 20 h reaction time), leading to full conversion of 2 and 73 % selectivity to 1, the main byproduct being 1,5-hexanediol (4). In a second approach, 2 was first converted to tetrahydropyran-2-methanol (2-THPM, 5) in quantitative yield using triflic acid as catalyst (125°C, 30 min). Various catalysts were explored for the subsequent ring opening/hydrodeoxygenation of 5 to 1 using a hydrogenation protocol and the best results were obtained with a Rh-ReO x /SiO 2 catalyst, viz. 96 % selectivity to 1 at 26 % conversion (120°C, 80 bar H 2 , 20 h).

show abstract

Section: Two-step Synthetic Approach Viamentioning

confidence: 99%

From 5-Hydroxymethylfurfural (HMF) to Polymer Precursors: Catalyst Screening Studies on the Conversion of 1,2,6-hexanetriol to 1,6-hexanediol

et al. 2012

View full text Add to dashboard Cite

show abstract

“…126 In the 2-catalyzed oxidative cyclization with hydrogen peroxide in water, the absorption of organic materials in the catalyst phase was similarly detected at 60°C, and higher reactivity owing to the hydrophobic effect was observed. The organic materials retained in gel were released by cooling the reaction mixture, and the organic/aqueous/solid phases were cleanly separated after the addition of diethyl ether.…”

Section: Thermoregulated Gel-phase Systemmentioning

confidence: 70%

Novel Recycling System for Organic Synthesis via Designer Polymer-Gel Catalysts

2009

Self Cite

View full text Add to dashboard Cite

“…6). 220) In 11a-catalyzed oxidative cyclization with hydrogen peroxide in water, absorption of organic materials in the catalyst phase was similarly detected at 60°C, and higher reactivity owing to hydrophobic effect was observed. The organic materials retained in gel were released by cooling the reaction mixture and the organic/aqueous/ solid phases were cleanly separated after addition of diethyl ether.…”

Section: Thermoregulated Gel-phase Systemmentioning

confidence: 89%

“…This work focuses much attention on the use of thermoregulated hydrophobic species formed by PNIPAAm as novel organic reaction medium in water. [214][215][216][217][218][219][220] Previously, our group found that an assembled complex of non-cross-linked PNIPAAm copolymer ligands and inorganic salts affords insoluble solids in water and possesses functions as a triphase catalyst. [221][222][223][224] To design a new oxometalate catalyzed oxidation system based on thermomorphic property of PNIPAAm, a dye-labeled catalyst 11b comprising a phosphotungstate anion, a PNIPAAm polymer chain, and a Disperse Red moiety was synthesized (Chart 7).…”

Section: Thermomorphic Property Of Polyoxometalatementioning

confidence: 99%

Development and Application of New Oxidation Systems Utilizing Oxometalate Catalysts

Hamamoto

2012

CHEMICAL & PHARMACEUTICAL BULLETIN

Self Cite

View full text Add to dashboard Cite

This review describes our recent efforts in the development and application of new oxidation systems utilizing oxometalate catalysts. The novel use of heteropoly acid (HPA), an acidic oxometalate catalyst, in hypervalent iodine-mediated oxidations provided an effective strategy to generate cation radical species that enables a variety of direct C-H functionalizations of aromatic compounds. This strategy brought a facile biaryl synthesis and new spirodienone syntheses in aromatic oxidation chemistry. Moreover, this strategy opens up a facile synthetic route to morphinandienone alkaloids. On the other hand, the use of oxometalate catalyst together with poly(N-isopropylacrylamide) (PNIPAAm)-based polymer in the development of new solid-phase catalyst provided a novel reaction system in water. Due to the characteristic temperature-responsive intelligence of PNIPAAm, this reaction system brought a remarkable acceleration of the reactivity and ease of catalyst recovering in catalytic oxidation that uses hydrogen peroxide or oxygen gas (O 2 ) as primary oxidant. In addition, the recovered solid-phase catalyst could be used for consecutive reactions without any significant loss of its catalytic efficacy.

show abstract

A New Solid‐Phase Reaction System Utilizing a Temperature‐ Responsive Catalyst: Oxidative Cyclization with Hydrogen Peroxide

Cited by 44 publications

References 57 publications

From 5-Hydroxymethylfurfural (HMF) to Polymer Precursors: Catalyst Screening Studies on the Conversion of 1,2,6-hexanetriol to 1,6-hexanediol

From 5-Hydroxymethylfurfural (HMF) to Polymer Precursors: Catalyst Screening Studies on the Conversion of 1,2,6-hexanetriol to 1,6-hexanediol

Novel Recycling System for Organic Synthesis via Designer Polymer-Gel Catalysts

Development and Application of New Oxidation Systems Utilizing Oxometalate Catalysts

Contact Info

Product

Resources

About