13633-25-5Relevant articles and documents
Shapiro,Jenkins
, p. 771 (1969)
Novel quaternary ammonium functional addition-type norbornene copolymer as hydroxide-conductive and durable anion exchange membrane for direct methanol fuel cells
He, Xiaohui,Liu, Jingyin,Zhu, Hongyu,Zheng, Yan,Chen, Defu
, p. 63215 - 63225 (2015)
Novel quaternary ammonium functional addition-type norbornene copolymers (QCnP(BN/PhBN), n = 1, 6, 10, 12) with different alkyl side chain length comb-shaped structures or different contents of 2-(4-phenyl-butoxymethy-lene)-5-norbornene (PhBN) (22-77%) are synthesized via copolymerization of functionalized norbornenes, and their corresponding hydroxide-conductive anion exchange membranes (AEMs) with effective hydrophilic-hydrophobic separation are prepared and confirmed by TEM or SEM. The achieved AEMs show high ion exchange capacity (1.83 mmol g-1), as well as low methanol permeability (1.97-20.4 × 10-7 cm2 s-1), which are lower than that of Nafion. The ionic conductivity increases with the operation temperature increasing and is observed up to 4.14 × 10-3 S cm-1. The AEMs exhibit excellent dimensional stability with a swelling degree in plane between 0.9-3.3% and good chemical stability under 6 M NaOH solution even after a month. Membrane electrode assembly (MEA) is fabricated by using the alkalized QC12P(BN/PhBN)-77 as the AEM and tested in an alkaline direct methanol fuel cell. The open circuit voltage (OVC) of 0.54 V and the maximum current density of 66 mW cm-2 are achieved at 80 °C, respectively.
Cs2CO3 promoted O-alkylation of alcohols for the preparation of mixed alkyl carbonates
Chu,Dueno,Kyung Woon Jung
, p. 1847 - 1850 (1999)
The presence of cesium carbonate and tetrabutylammonium iodide (TBAI) facilitated efficient O-alkylation of alcohols with alkyl halides, giving rise to the exclusive formation of mixed alkyl carbonates. The cesium effect was also examined comparatively with other alkali carbonates.
Regiodivergent Conversion of Alkenes to Branched or Linear Alkylpyridines
Kim, Minseok,Shin, Sanghoon,Koo, Yejin,Jung, Sungwoo,Hong, Sungwoo
supporting information, p. 708 - 713 (2022/01/20)
Herein we report a practical protocol for the visible-light-induced regiodivergent radical hydropyridylation of unactivated alkenes using pyridinium salts. This approach provides a unified synthetic platform to control the regioselectivity of the synthesis of linear or branched C4-alkylated pyridines. A remarkable selectivity switch from the anti-Markovnikov to the Markovnikov product can be achieved by the addition of tetrabutylammonium bromide. The versatility of this protocol is further demonstrated based on the late-stage functionalization in pharmaceuticals.
Substrate and Catalyst Effects in the Enantioselective Copper-Catalysed C–H Insertion Reactions of α-Diazo-β-oxo Sulfones
Shiely, Amy E.,Clarke, Leslie-Ann,Flynn, Christopher J.,Buckley, Aoife M.,Ford, Alan,Lawrence, Simon E.,Maguire, Anita R.
, p. 2277 - 2289 (2018/06/04)
Excellent enantioselectivities of up to 98 % ee are achieved by employing the copper-bis(oxazoline)-NaBARF catalyst system in the C–H insertion reactions of α-diazo-β-oxo sulfones. The influence of variation of the bis(oxazoline) ligand, copper salt, additive and substrate on both the efficiency and the enantioselectivities of these intramolecular C–H insertion reactions has been explored. Optimum enantioselectivities are achieved with phenyl and diphenyl ligands across the substrate series.