Novel C1-symmetric chiral crown ethers bearing rosin acids groups: synthesis and enantiomeric recognition for ammonium salts
作者:Lu-zhi Liu、Chun-huan He、Lin Yang、Yan Huang、Qiang Wu、Wen-gui Duan、Heng-shan Wang、Ying-ming Pan
DOI:10.1016/j.tet.2014.10.050
日期:2014.12
novel C1-symmetric chiralcrownethers including 28-crown-8, 20-crown-6, 17-crown-5 and 14-crown-3 (9a–m) were synthesized and their enantiodiscriminating abilities with protonated primary amines (10–14) were examined by 1H NMR spectroscopy. 20-crown-6 crownethers exhibited good chiralrecognition properties toward these guests and showed different complementarity to some chiral guests, indicating
合成了四种新型的C 1-对称的手性冠醚,包括28冠8、20冠6、17冠5和14冠3(9a - m),以及它们与质子化伯胺的对映能力。 (10 – 14)人接受了1次检查1 H NMR光谱。20冠6冠醚对这些客体表现出良好的手性识别特性,并且与某些手性客体表现出不同的互补性,表明20冠6冠醚可以用作手性NMR溶剂确定这些客人的对映体纯度。此外,还通过计算建模和实验计算研究了宿主与客体之间的结合模型和结合位点。
A heterometallic (Fe<sub>6</sub>Na<sub>8</sub>) cage-like silsesquioxane: synthesis, structure, spin glass behavior and high catalytic activity
作者:Alexey N. Bilyachenko、Mikhail M. Levitsky、Alexey I. Yalymov、Alexander A. Korlyukov、Anna V. Vologzhanina、Yuriy N. Kozlov、Lidia S. Shul'pina、Dmytro S. Nesterov、Armando J. L. Pombeiro、Frédéric Lamaty、Xavier Bantreil、Amandine Fetre、Diyang Liu、Jean Martinez、Jérôme Long、Joulia Larionova、Yannick Guari、Alexander L. Trigub、Yan V. Zubavichus、Igor E. Golub、Oleg A. Filippov、Elena S. Shubina、Georgiy B. Shul'pin
DOI:10.1039/c6ra07081g
日期:——
The exotic "Asian Lantern" heterometallic cage silsesquioxane [(PhSiO1.5)20(FeO1.5)6(NaO0.5)8(n-BuOH)9.6(C7H8)] (I) was obtained and characterized by X-ray diffraction, EXAFS, topological analyses and DFT calculation. The magnetic properties investigations revealed that it shows...
Copper(II)–guanidine acetic acidcomplex was immobilized on the surface of magnetized raw waste sawdust (SD) as an abundant natural biopolymer and employed as an efficient and recoverable catalyst in oxidative amidation reaction, while waste eggshell (ES) powder was used as a low-cost solid base. The magnetic raw catalyst was fully characterized using FTIR, XRD, SEM, EDX, TGA, and VSM. A variety of
Direct Preparation of Amides from Amine Hydrochloride Salts and Orthoesters: A Synthetic and Mechanistic Perspective
作者:Martin J. Di Grandi、Caitlin Bennett、Kristen Cagino、Arnold Muccini、Corey Suraci、Shahrokh Saba
DOI:10.1080/00397911.2015.1096943
日期:2015.11.17
Abstract The conversion of a wide range of primary and secondary aliphatic and a few arylamine hydrochloridesalts to their corresponding acetamides with trimethyl orthoacetate is described. Mechanistic studies using NMR and gas chromatography–mass spectrometry techniques indicate these reactions proceed via an O-methylimidate intermediate that undergoes in situ demethylation by chloride, affording