4771-08-8Relevant articles and documents
Synthesis of polyaramids in γ-valerolactone-based organic electrolyte solutions
Winters, Jonas,Bolia, Raheed,Dehaen, Wim,Binnemans, Koen
supporting information, p. 1228 - 1239 (2021/02/26)
The current synthetic procedures for polyaramids mainly involve the use of amide solvents such asN-methylpyrrolidone andN,N-dimethylacetamide. However, these solvents are suspected to be teratogenic and are considered ‘Substances of Very High Concern’ by the European Commission. Here we propose a benign alternative solvent system: an Organic Electrolyte Solution (OES) consisting of γ-valerolactone (GVL) and a small amount of the ionic liquid 1-methyl-3-octylimidazolium chloride, [C8MIm][Cl]. Three commercially relevant polyaramids were synthesized: poly-p-phenylene terephthalamide (PPTA), poly-m-phenylene isophthalamide (PMIA) and copoly(p-phenylene/3,4′-diphenylether terephthalamide) (ODA/PPTA). PMIA was successfully synthesized in the OES containing [C8MIm][Cl] in a molar fraction ofxIL= 0.043, achieving an inherent viscosity ofηinh= 1.94 ± 0.064 dL g?1, which is on par with the current industrial standard and the benchmark lab scale synthesis. The reaction mixture could also be directly used for the wet spinning of polyaramid fibers, and all components of the solvent could be recycled in good yields by a series of evaporation and distillation steps. ODA/PPTA could be synthesized, but only rather low inherent viscosities were achieved. The reaction mixture was too viscoelastic to be spun by our small-scale spinning setup. PPTA always instantly precipitated and could not be synthesized from a [C8MIm][Cl]/GVL OES. α-Picoline, the organic base which was added to capture the released HCl during the reaction, was found to play a pivotal role in the polymerization reaction. By undergoing an acid-base reaction with HCl, it forms a protic ionic liquidin situwhich increases the solubility of the polymer.
Iron-catalyzed cross-coupling of N?methoxy amides and arylboronic acids for the synthesis of N-aryl amides
Li, Jinhui,Liu, Jin-Biao,Luo, Nianhua,Qiu, Guanyinsheng,Ren, Shangfeng,Wang, Ying,Xie, Huilin
, (2021/11/11)
An efficient iron-catalyzed synthesis of N-aryl amides from N?methoxy amides and arylboronic acids is developed. FeCl3 is used as the sole catalyst for the cross-coupling reaction between N?methoxy amides and arylboronic acids without any other
Synthesis of 2-Amino-1,3-dienes from Propargyl Carbonates via Palladium-Catalyzed Carbon-Nitrogen Bond Formation
O'Broin, Calvin Q.,Guiry, Patrick J.
supporting information, p. 879 - 883 (2020/02/04)
A catalytic method to synthesize 1,3,-dienes from propargylic precursors is reported. This palladium-catalyzed carbon-nitrogen bond-forming reaction furnishes 2-amino-1,3-dienes in excellent yields (up to 98%) and shows a broad tolerance to functional group diversity. The reaction has been demonstrated for over 30 amine substrates, including anilines and indoles, and proceeds under mild neutral conditions. The resulting 1,3-dienes are of great synthetic interest because of their further reaction potential.
