Chemistry of diimide. Some new systems for the hydrogenation of multiple bonds

Corey, E. J.; Mock, William L.; Pasto, Daniel J.

doi:10.1016/s0040-4039(01)91637-5

Cited by 131 publications

(62 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Table 3 shows the product distribution in the catalytic aerobic reduction of phenyl 2-propenyl sulfide (10) in the presence of varying amounts of phenol. The reaction of 10 with less than 1 equiv of phenol affords the hydrogenated product, phenyl propyl sulfide (11), selectively (Table 3, entry 1), whereas similar treatment with a large amount of phenol affords increasing amounts of the S-oxidation products, phenyl 2-propenyl sulfoxide (12) and phenyl propyl sulfoxide (13). Such a drastic change in chemoselectivity has previously been observed exclusively with highly acidic alcohols such as phenol (pK a 9.99) and CF 3 CH 2 OH (12.4).…”

Section: Resultsmentioning

confidence: 99%

Aerobic Reduction of Olefins by In Situ Generation of Diimide with Synthetic Flavin Catalysts

Imada

Iida

Kondo

et al. 2011

Chemistry A European J

View full text Add to dashboard Cite

A versatile reducing agent, diimide, can be generated efficiently by the aerobic oxidation of hydrazine with neutral and cationic synthetic flavin catalysts 1 and 2. This technique provides a convenient and safe method for the aerobic reduction of olefins, which proceeds with 1 equiv of hydrazine under an atmosphere of O(2) or air. The synthetic advantage over the conventional gas-based method has been illustrated through high hydrazine efficiency, easy and safe handling, and characteristic chemoselectivity. Vitamin B(2) derivative 6 acts as a highly practical, robust catalyst for this purpose because of its high availability and recyclability. Association complexes of 1b with dendritic 2,5-bis(acylamino)pyridine 15 exhibit unprecedented catalytic activities, with the reduction of aromatic and hydroxy olefins proceeding significantly faster when a higher-generation dendrimer is used as a host pair for the association catalysts. Contrasting retardation is observed upon similar treatment of non-aromatic or non-hydroxy olefins with the dendrimer catalysts. Control experiments and kinetic studies revealed that these catalytic reactions include two independent, anaerobic and aerobic, processes for the generation of diimide from hydrazine. Positive and negative dendrimer effects on the catalytic reactions have been ascribed to the specific inclusion of hydrazine and olefinic substrates into the enzyme-like reaction cavities of the association complex catalysts.

show abstract

Section: Resultsmentioning

confidence: 99%

Aerobic Reduction of Olefins by In Situ Generation of Diimide with Synthetic Flavin Catalysts

Imada

Iida

Kondo

et al. 2011

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…The reduction of double bond has also been carried out with hydrazine hydrate over a diimid (HN=NH) intermediate (43). Rollas's method (26,27) gave also the reduced azo products along with the reduced allyl group compound 9 and compound 14 (Scheme 5).…”

Section: Other Reductions With Hydrazine Hydratementioning

confidence: 99%

Reduction of aromatic and heteroaromatic azo compounds with hydrazine hydrate

Rollas¹

2010

mpj

View full text Add to dashboard Cite

“…There was no evidence that it had any effect on the reactivity with the double bond. 17 The Cu(II) ion only accelerates the rate of oxidation of hydrazine, that is, it enhances the rate of the formation of diimide. Now, as the styrene content of the latex increases, the stabilization of Cu(II) on the polymer particle/soap interface decreases due to the steric hindrance and higher stiffness of the chain.…”

Section: Dependence Of Degree Of Hydrogenation On Catalyst Concentratmentioning

confidence: 99%

“…SBR lattices having 17,23,28, and 38% styrene content were used in this study. The variables chosen were time, temperature, and concentration of the reactants and the catalyst.…”

Section: Introductionmentioning

confidence: 99%

Influence of styrene content on the hydrogenation of styrene-butadiene copolymer

Sarkar¹,

De²,

Bhowmick³

1999

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

A hydrogenated styrene-butadiene copolymer (HSBR) was prepared by a diimide reduction of SBR in the latex stage. The influence of the styrene content on various reaction parameters, namely, time, temperature, and concentration of the reactants and the catalyst was studied. A comparatively lower temperature, longer time, lesser amount of hydrogen peroxide, and higher amount of the catalyst are required to optimize the hydrogenation reactions of SBR with a higher styrene content. The diimide reduction of SBR is first order with respect to the olefinic substrate and the apparent activation energy increases with increase in the styrene level. All the hydrogenated copolymers were characterized with the help of IR, NMR, and DSC. The TGA data indicate a higher thermal stability of HSBR as compared to SBR in nitrogen, although an anomalous behavior is observed in air due to crosslinking and oxidation.

show abstract

Chemistry of diimide. Some new systems for the hydrogenation of multiple bonds

Cited by 131 publications

References 8 publications

Aerobic Reduction of Olefins by In Situ Generation of Diimide with Synthetic Flavin Catalysts

Aerobic Reduction of Olefins by In Situ Generation of Diimide with Synthetic Flavin Catalysts

Reduction of aromatic and heteroaromatic azo compounds with hydrazine hydrate

Influence of styrene content on the hydrogenation of styrene-butadiene copolymer

Contact Info

Product

Resources

About