We report herein a new methodology for the rapid and selective reduction of carbonyls in the solid phase. By exploiting mechanical energy and using a cheap and air-stable silane, polymethylhydrosiloxane (PMHS), we can reduce a variety of carbonyl compounds, with catalytic
Amine N‐alkylation is a process involved in the production of a wide range of chemicals. Here we describe the synthesis of well‐defined (Ni0.5Cu0.5)Fe2O4 magnetic nanoparticles by plasma induction, and their successful application to amine N‐alkylation using alcohols as coupling agents through a borrowing hydrogen pathway. Plasma induction allows precise morphology and size control over nanoparticle synthesis, while allowing the one‐pot production of decagram quantities of material. Up to date, such nanoparticles have never been applied for organic reactions. By coupling high‐end characterization techniques with catalytic optimization, we showed that small Cu(0) satellite nanoparticles played an essential role in alcohol oxidation, whereas both Ni and Cu were required for the last step of the reaction. Using elemental mapping, we demonstrated that catalyst deactivation occurred through a leaching/re‐deposition mechanism of Cu and Ni. The reactions were conducted under microwave conditions, which exerted a positive effect on catalytic activity. Finally, the catalyst was active at low metal loadings (2 mol%) even on the gram‐scale, and affording unprecedented TON for this reaction catalyzed by Ni/Cu bimetallic systems (19).
На керамических образцах системы твердых растворов (1-2x)BiScO3· xPbTiO3· xPbMg1/3Nb2/3O3 (0.30≤ x≤0.46) со структурой перовскита выполнены рентгенографические, диэлектрические, пьезоэлектрические и пироэлектрические исследования. Найдено, что симметрия твердых растворов изменяется с ростом x от ромбоэдрической (x≤0.38) до тетрагональной (x≥0.42). Образцы с 0.30<x≤0.42 имеют характерные для сегнетоэлектриков-релаксоров свойства, проявляющиеся в наличии широкого пика на температурной зависимости диэлектрической проницаемости при Tmvarepsilon=390-440 K, положение которого смещается с частотой в сторону высоких температур, узких ненасыщенных петель диэлектрического гистерезиса, индуцированного электрическим полем перехода в сегнетоэлектрическое состояние при 318 K. Обнаруженные особенности диэлектрических, пьезо- и пироэлектрических свойств изученных твердых растворов объясняются принадлежностью их к сегнетоэлектрикам-релаксорам. Работа выполнена при поддержке Министерства образования и науки РФ (проект N 3.734.2014/К проектной части госзадания) и РФФИ (грант N 15-02-04647). DOI: 10.21883/FTT.2017.01.43947.431
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