example of a homogeneous catalyst based on an earth‐abundant metal for the hydrogenation of organic carbonates to methanol and alcohols is reported. Based on the mechanistic investigation, which indicates metal‐ligand cooperation between the manganese center and the N−H group of the pincer ligand, we propose that the hydrogenation of organic carbonates to methanol occurs via formate and aldehyde intermediates
practical lanthanide(III)-catalyzed transesterification of carboxylic esters, weakly reactive carbonates, and much less-reactive ethyl silicate with primary and secondary alcohols was developed. Heterobimetallic dinuclear lanthanidealkoxide complexes [Ln2Na8(OCH2CH2NMe2)}12(OH)2] (Ln = Nd (I), Sm (II), and Yb (III)) were used as highly active catalysts for this reaction. The mild reaction conditions enabled
Synthesis of non-symmetrical alkyl carbonates from alcohols and DMC over the nanocrystalline ZSM-5 zeolite
作者:Durgaiah Chevella、Arun Kumar Macharla、Rammurthy Banothu、Krishna Sai Gajula、Vasu Amrutham、Murali Boosa、Narender Nama
DOI:10.1039/c9gc00541b
日期:——
A novel heterogeneous acid (nanocrystalline ZSM-5) catalyzed carboxymethylation of alcohols to non-symmetrical alkyl carbonates using DMC has been realized. Nanocrystalline ZSM-5 (NZSM-5) with a crystal size of 20–30 nm was synthesized by hydrothermal crystallization. The synthesized NZSM-5 was verified by X-ray diffraction, Fourier transformation infrared spectroscopy and solid state NMR. The morphology
已经实现了使用DMC的新型异质酸(纳米晶体ZSM-5)催化醇的羧甲基化为不对称的碳酸烷基酯。通过水热结晶合成了晶体大小为20–30 nm的纳米晶体ZSM-5(NZSM-5)。合成的NZSM-5通过X射线衍射,傅立叶变换红外光谱和固态NMR进行验证。透射电子显微镜和扫描电子显微镜证实了NZSM-5的形态,揭示了由纳米大小(20-30 nm)的NZSM-5颗粒堆积形成的沸石(100-200 nm)聚集体的形成。NZSM-5的理化性质通过氮的吸附和程序升温的氨解吸来测量,这表明表面积为465 m 2 g -1酸度为0.936 mmol g -1。本协议为高产量的各种非对称碳酸烷基酯提供了一种有吸引力的方法。催化剂被有效地循环多达5个连续循环。这种方法拓宽了DMC在绿色化学中可能的利用范围。
Chemoselective Synthesis of Asymmetrical Carbonate from Alcohol and Dimethyl Carbonate Catalyzed by Ytterbium(III) Triflate
Abstract Catalyzed by ytterbium(III) triflate, asymmetrical carbonate can be chemoselectively synthesized from alcohols and dimethyl carbonate (DMC) in moderate to good yield under the mild conditions.
Synthesis of Carbonate Esters by Carboxymethylation Using NaAlO<sub>2</sub> as a Highly Active Heterogeneous Catalyst
作者:Sreerangappa Ramesh、Kiran Indukuri、Olivier Riant、Damien P. Debecker
DOI:10.1021/acs.oprd.8b00333
日期:2018.12.21
Sodium aluminate is presented as a highlyactive heterogeneous catalyst that is able to convert a range of alcohols into the corresponding unsymmetrical carbonate esters by reaction with dimethyl carbonate. Preparing NaAlO2 via spray drying boosts the basic properties and the activity of the catalyst.