- General methodology for the chemoselective N-alkylation of (2,2,6,6)-tetramethylpiperidin-4-ol: Contribution of microwave irradiation
-
A convenient method to access a broad variety of N-alkyl-(2,2,6,6)-tetramethylpiperidin-4-ol compounds is reported. The thermal treatment of a mixture of (2,2,6,6)-tetramethylpiperidin-4-ol and allyl or benzyl bromide derivatives gave the corresponding N–alkylated compounds in good yields while leaving the hydroxyl functional group intact. Whereas 40 h were needed to reach complete conversion, microwave irradiation allowed the reaction time to be reduced (20 min) and improved the yields in most cases.
- Membrat, Romain,Vasseur, Alexandre,Giordano, Laurent,Martinez, Alexandre,Nuel, Didier
-
supporting information
p. 240 - 243
(2019/01/04)
-
- Phosphinous Acid Platinum Complex as Robust Catalyst for Oxidation: Comparison with Palladium and Mechanistic Investigations
-
Secondary phosphine oxides proved to be effective preligands to stabilise a hydroxy-platinum based catalyst that allows the aerobic/anaerobic oxidation of challenging substrates. Kinetic comparisons showed that this system is more efficient and stable than previously reported similar palladium-based catalysts. A neutral platinum dimer bearing bridging hydroxy ligands has been isolated and fully characterised by X-ray diffraction and its involvement in the mechanism has been evidenced by mechanistic studies.
- Membrat, Romain,Vasseur, Alexandre,Martinez, Alexandre,Giordano, Laurent,Nuel, Didier
-
p. 5427 - 5434
(2018/10/20)
-
- COMPOUNDS AND LIQUID-CRYSTALLINE MEDIUM
-
Compounds of the formula I, and liquid-crystalline media, preferably having a nematic phase and negative dielectric anisotropy, comprising a) one or more compounds of the formula I and one or more compounds selected from b) one or more compounds of formula II and/or c) one or more compounds selected from compounds of formulae III-1 to III-4 and formula B Methods for making and using these liquid-crystalline media in electro-optical displays, particularly in active-matrix displays based on the VA, ECB, PALC, FFS or IPS effect and the displays which contain these media. Methods for stabilizing liquid-crystalline media with compounds of formula I, where the liquid-crystalline media comprise one or more compounds of the formula II and one or more compounds selected from compounds of the formulae III-1 to III-4 and formula B.
- -
-
Paragraph 0413; 0414
(2018/08/20)
-
- Substituted piperidin-4-ols
-
Disclosed are stabilized compositions comprising a polymer, especially polyolefines, and a minor proportion of a 1,2,2,6,6-pentasubstituted piperidin-4-ol. The new compositions possess good light stability.
- -
-
-