scholarly journals Selective production of bio-based aromatics by aerobic oxidation of native soft wood lignin in tetrabutylammonium hydroxide

RSC Advances ◽  
2020 ◽  
Vol 10 (33) ◽  
pp. 19199-19210 ◽  
Author(s):  
Takashi Hosoya ◽  
Kohei Yamamoto ◽  
Hisashi Miyafuji ◽  
Tatsuhiko Yamada
Keyword(s):  
Aqueous Solution ◽  
Aerobic Oxidation ◽  
Efficient Production ◽  
Tetrabutylammonium Hydroxide ◽  
Platform Chemicals

Aerobic oxidation of native soft wood lignin in an aqueous solution of Bu4NOH facilitates efficient production of vanillin (4-hydroxy-3-methoxybenzaldehyde), which is one of the platform chemicals in industry.

Study of aerobic oxidation of phenyl PtII complexes (dpms)PtIIPh(L) (dpms = di(2-pyridyl)methanesulfonate; L = water, methanol, or aniline)

2009 ◽  
Vol 87 (1) ◽  
pp. 110-120 ◽  
Author(s):  
Julia R Khusnutdinova ◽  
Peter Y Zavalij ◽  
Andrei N Vedernikov
Keyword(s):  
Aqueous Solution ◽  
Aerobic Oxidation ◽  
Reductive Elimination ◽  
High Yield ◽  
Ambient Conditions ◽  
Activation Barriers ◽  
Methanol Solutions ◽  
Anionic Species ◽  
Mechanism Of Oxidation ◽  
Solution Mechanism

Oxidation of phenyl PtII complexes K[(dpms)PtIIPh2], 1, (dpms)PtIIPh(MeOH), 2, (dpms)PtIIPh(OH2), 3, and methyl PtII complex (dpms)PtIIMe(NH2Ph), 6, with O2 in aqueous or methanol solutions under ambient conditions leads to corresponding (dpms)PtIVR(X)OH complexes (R = X = Ph, 7; R = Ph, X = OH, 8; R = Ph, X = OMe, 9; R = Me, X = NHPh; 11; dpms = di(2-pyridyl)methanesulfonate). Complexes 7–9 could be isolated in high yield. Complex 11 as well as its phenyl analogue (dpms)PtIVPh(NHPh)OH, 10 can be prepared in high yield by oxidation of corresponding (dpms)PtIIR(NH2Ph) with H2O2 in methanol. Phenyl PtII complexes (dpms)PtIIPh(HX) derived from HX = aniline and DMSO, 4 and 5, respectively, are inert toward O2. The rate of oxidation of 1–5 with O2 decreases in the order 1 > 3 ~ 2 » 4, and 5 is unreactive. Methyl analogues are significantly more reactive compared with their phenyl counterparts. Proposed mechanism of oxidation with O2 includes formation of anionic species (dpms)PtIIR(X)– responsible for reaction with dioxygen. Attempts at C–O and C–N reductive elimination from phenyl PtIV complexes 7–10 do not lead to phenyl derivatives PhX at 80–100 °C, consistent with the results of the DFT estimates of corresponding activation barriers, ΔG0 exceeding 28 kcal/mol.Key words: platinum phenyl complexes, oxidation, dioxygen, aqueous solution, mechanism.

Silk Fibroin Dissolution in Tetrabutylammonium Hydroxide Aqueous Solution

2019 ◽  
Vol 20 (11) ◽  
pp. 4107-4116 ◽  
Author(s):  
Bruno Medronho ◽  
Alexandra Filipe ◽  
Sofia Napso ◽  
Rafail. L. Khalfin ◽  
Rui F. P. Pereira ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Silk Fibroin ◽  
Tetrabutylammonium Hydroxide

Efficient Production of Biomass-Derived C4Chiral Synthons in Aqueous Solution

ChemCatChem ◽  
2017 ◽  
Vol 9 (22) ◽  
pp. 4179-4184 ◽  
Author(s):  
Shaoying Lin ◽  
Xiao Guo ◽  
Kai Qin ◽  
Lei Feng ◽  
Yahong Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Efficient Production
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