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We have successfully isolated and characterized the zinc carbamate complex (phen)Zn(OAc)(OC(=O)NHPh) (1; phen=1,10‐phenanthroline), formed as an intermediate during the Zn(OAc)2/phen‐catalyzed synthesis of organic carbamates from CO2, amines, and the reusable reactant Si(OMe)4. Density functional theory calculations revealed that the direct reaction of 1 with Si(OMe)4 proceeds via a five‐coordinate silicon intermediate, forming organic carbamates. Based on these results, the catalytic system was improved by using Si(OMe)4 as the reaction solvent and additives like KOMe and KF, which promote the formation of the five‐coordinated silicon species. This sustainable and effective method can be used to synthesize various N‐aryl and N‐alkyl carbamates, including industrially important polyurethane raw materials, starting from CO2 under atmospheric pressure. [ABSTRACT FROM AUTHOR]

New sustainable approaches should be developed to overcome equilibrium limitation of dialkyl carbonate synthesis from CO2 and alcohols. Using tetraethyl orthosilicate (TEOS) and CO2 with Zr catalysts, we report the first example of sustainable catalytic synthesis of diethyl carbonate (DEC). The disiloxane byproduct can be reverted to TEOS. Under the same conditions, DEC can be synthesized using a wide range of alkoxysilane substrates by investigating the effects of the number of ethoxy substituent in alkoxysilane substrates, alkyl chain, and unsaturated moiety on the fundamental property of this reaction. Mechanistic insights obtained by kinetic studies, labeling experiments, and spectroscopic investigations reveal that DEC is generated via nucleophilic ethoxylation of a CO2‐inserted Zr catalyst and catalyst regeneration by TEOS. The unprecedented transformation offers a new approach toward a cleaner route for DEC synthesis using recyclable alkoxysilane. [ABSTRACT FROM AUTHOR]

Amines, carbon dioxide fixation, density functional calculations, sustainable chemistry, zinc Cover Feature: N-Aryl and N-Alkyl Carbamates from 1 Atmosphere of CO2 (Chem. Eur. J. 72/2021) Keywords: amines; carbon dioxide fixation; density functional calculations; sustainable chemistry; zinc EN amines carbon dioxide fixation density functional calculations sustainable chemistry zinc 17974 17974 1 12/27/21 20211223 NES 211223 B We have successfully isolated b the zinc carbamate complex (phen)Zn(OAc)(OC(=O)NHPh) ( B 1 b , phen=1,10-phenanthroline), which is an intermediate in the Zn(OAc) SB 2 sb /phen-catalyzed synthesis of organic carbamates from CO SB 2 sb , amines, and Si(OMe) SB 4 sb . [Extracted from the article]

Keywords: alkoxysilane; carbon dioxide; diethyl carbonate; sustainable catalytic synthesis; Zr catalysts EN alkoxysilane carbon dioxide diethyl carbonate sustainable catalytic synthesis Zr catalysts 755 755 1 02/17/21 20210205 NES 210205 B The Cover Feature b shows the new synthesis of diethyl carbonate from CO SB 2 sb and alkoxysilanes using a zirconium catalyst. Alkoxysilane, carbon dioxide, diethyl carbonate, sustainable catalytic synthesis, Zr catalysts. [Extracted from the article]

A novel solution-processable low molecular weight organic semiconductor material TS-5, which has high thermal stability and solubility with various aromatic solvents, was developed. Field effect transistors (FET) fabricated using TS-5 as an active layer, exhibited p-type transistor responses with mobilities greater than 1.0 cm2/Vs and are stable at 150°C in air condition. [ABSTRACT FROM AUTHOR]

A heterogeneous zirconium catalyst was grafted on a ceria‐coated silica support, denoted as Zr(OEt)x/CeO2/SiO2. It exhibited higher catalytic activity compared to its homogeneous counterpart, Zr(OEt)4, in the conversion of carbon dioxide to diethyl carbonate using tetraethyl orthosilicate as a regenerable agent in the absence of any dehydrating agents under non‐protic conditions. We found that the ceria‐coated silica (CeO2/SiO2) support not only improved the catalytic activity of Zr(OEt)4 but also inhibited catalyst deactivation during catalyst recycling tests. Furthermore, we analyzed the surface of the Zr(OEt)x/CeO2/SiO2 catalysts by FE‐SEM and EDX. [ABSTRACT FROM AUTHOR]

We have successfully isolated and characterized the zinc carbamate complex (phen)Zn(OAc)(OC(=O)NHPh) (1; phen=1,10‐phenanthroline), formed as an intermediate during the Zn(OAc)2/phen‐catalyzed synthesis of organic carbamates from CO2, amines, and the reusable reactant Si(OMe)4. Density functional theory calculations revealed that the direct reaction of 1 with Si(OMe)4 proceeds via a five‐coordinate silicon intermediate, forming organic carbamates. Based on these results, the catalytic system was improved by using Si(OMe)4 as the reaction solvent and additives like KOMe and KF, which promote the formation of the five‐coordinated silicon species. This sustainable and effective method can be used to synthesize various N‐aryl and N‐alkyl carbamates, including industrially important polyurethane raw materials, starting from CO2 under atmospheric pressure. [ABSTRACT FROM AUTHOR]