Effect of Added Salt on Ring-Closing Metathesis Catalyzed by a Water-Soluble Hoveyda–Grubbs Type Complex To Form N-Containing Heterocycles in Aqueous Media

Matsuo, Takashi; Yoshida, Takefumi; Fujii, Akira; Kawahara, Keiya; Hirota, Shun

doi:10.1021/om4005302

Cited by 41 publications

(47 citation statements)

References 53 publications

(22 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Al ikely explanation for this observation is the smalli ncreasei ns olubility of the catalyst compared to catalyst C2,w hichc ontains partly hydrophobic triflate anions. With catalyst C1,f urther attempts to increaset he self-metathesis yields were based on observations made by Davis et al [54] and Hirota et al, [62] in which addition of ac hloride salt prevented nonproductive chelation/deactivation of the catalysts. In the present case, addition of magnesium chloride( 100 mm)i mproved the self-metathesis conversions only marginally in the reactions with the functionalized carbohydrates.…”

Section: Resultsmentioning

confidence: 99%

Acid‐Assisted Direct Olefin Metathesis of Unprotected Carbohydrates in Water

Timmer

Ramström

2019

Chemistry A European J

View full text Add to dashboard Cite

The ability to use unprotectedc arbohydrates in olefin metathesis reactions in aqueous media is demonstrated. By using water-soluble, amine-functionalized Hoveyda-Grubbs catalysts under mildly acidic aqueousc onditions, the self-metathesis of unprotecteda lkene-functionalized a-dmanno-and a-d-galactopyranosides could be achieved through minimization of nonproductive chelation and isomerization. Cross-metathesis with allyl alcoholc ould also be achieved with reasonable selectivity. The presence of small quantities (2.5vol %) of acetic acid increased the formation of the self-metathesis product while significantly reducing the alkenei somerization process. The catalytic activityw as furthermore retained in the presenceo fl arge amounts (0.01 mm)o fp rotein, underlining the potential of this carbon-carbon bond-formingr eactionu nder biological conditions. These results demonstrate the potential of directly using unprotectedc arbohydrates tructures in olefin metathesis reactions under mild conditions compatible with biological systems, and therebye nabling their use in, for example, drug discovery and protein derivatization.Supporting information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.

show abstract

Section: Resultsmentioning

confidence: 99%

Acid‐Assisted Direct Olefin Metathesis of Unprotected Carbohydrates in Water

Timmer

Ramström

2019

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…It was observed that the particle size was smaller with ionic stabilization (CTAC and CTAB) compared to Triton X‐100. With SDS, the polymerization did not occur at all, likely due to the sulfate group of SDS and the catalyst forming inactive species . We also found that dodecane was an effective miniemulsion costabilizer at low concentration (0.5 wt% based on monomer).…”

Section: Summary Of Experimental Results: Experiment Molar Ratio Monmentioning

confidence: 72%

Synthesis of Diblock and Triblock Polymers from Cyclooctadiene and Norbornene Via ROMP in Miniemulsion

Torres‐Rocha

Zhu

et al. 2019

Macromol. Rapid Commun.

View full text Add to dashboard Cite

The synthesis of diblock and triblock linear polyolefins via ring opening metathesis polymerization (ROMP) in an aqueous nanoparticle dispersion is presented. The different block polyolefins are synthesized from the cyclic olefins 1,5‐cyclooctadiene and norbornene (NB), using a water‐soluble TEGylated ruthenium alkylidene catalyst, yielding the structures PCOD‐b‐PNB, PNB‐b‐PCOD, and PCOD‐b‐PNB‐b‐PCOD. High monomer conversion (>90%), monitored by NMR, is achieved in relatively short times (≈1 h) for the polymerization of each block. The livingness of the system, essential to obtain block copolymers, is confirmed by gel permeation chromatography. Latex particles' size during the multiple steps range between 90 and 150 nm. The results demonstrate that it is possible to obtain nanoparticle latexes from ROMP‐based monomers with block copolymer architectures, creating the opportunity to copolymerize olefins bearing different functional groups for the synthesis of new materials.

show abstract

“…Under slightly acidic conditions (pH 5.8), full conversion was observed with the metal complex coupled to the fully unfolded protein ( Table 2 , entries 2–4) [ 59 – 60 ]. This effect was attributed to the pH and was investigated in detail [ 61 ].…”

Section: Reviewmentioning

confidence: 99%