78-08-0Relevant articles and documents
Sustainable Catalytic Synthesis of Diethyl Carbonate
Putro, Wahyu S.,Ikeda, Akira,Shigeyasu, Shinji,Hamura, Satoshi,Matsumoto, Seiji,Lee, Vladimir Ya.,Choi, Jun-Chul,Fukaya, Norihisa
, p. 842 - 846 (2020/12/07)
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.
Fe and Co Complexes of Rigidly Planar Phosphino-Quinoline-Pyridine Ligands for Catalytic Hydrosilylation and Dehydrogenative Silylation
Basu, Debashis,Gilbert-Wilson, Ryan,Gray, Danielle L.,Rauchfuss, Thomas B.,Dash, Aswini K.
, p. 2760 - 2768 (2018/09/10)
Co and Fe dihalide complexes of a new rigidly planar PNN ligand platform are prepared and examined as precatalysts for hydrosilylation of alkenes. Lithiation of Thummel's 8-bromo-2-(pyrid-2′-yl)quinoline followed by treatment with (i-Pr)2PCl and (C6F5)2PCl afforded the phosphine-quinoline-pyridine ligands, abbreviated RPQpy for R = i-Pr and C6F5, respectively. These ligands form 1:1 adducts with the dichlorides and dibromides of iron and cobalt. Crystallographic characterization of FeBr2(iPrPQpy), FeBr2(ArFPQpy), CoCl2(iPrPQpy), CoBr2(iPrPQpy), and CoCl2(ArFPQpy) confirmed that the M-P-C-C-N-C-C-N portion of these complexes is planar within 0.078 ? unlike previous generations of PNN complexes where deviations from planarity were ~0.35 ?. Bond distances as well as magnetism indicate that the Fe complexes are high spin and the cobalt complexes are high spin or participate in spin equilibria. Also investigated were the NNN analogues of the RPQpy ligands, wherein the phosphine group was replaced by the mesityl ketimine. The complexes FeBr2(MesNQpy) and CoCl2(MesNQpy) were characterized crystallographically. Reduction of MX2(RPQpy) complexes with NaBHEt3 generates catalysts active for anti-Markovnikov silylation of simple and complex 1-alkenes with a variety of hydrosilanes. Catalysts derived from MesNQpy exhibited low activity. Fe-RPQpy derived catalysts favor hydrosilylation, whereas Co-RPQpy based catalysts favor dehydrogenative silylation. Catalysts derived from CoX2(iPrPQpy) convert hydrosilanes and ethylene to vinylsilanes. Related experiments were conducted on propylene to give propenylsilanes.
Ruthenium-catalyzed dealkenative N-silylation of amines by substituted vinylsilanes
Marciniec, Bogdan,Kostera, Sylwia,Wyrzykiewicz, Bozena,Pawlu, Piotr
supporting information, p. 782 - 786 (2015/02/19)
The ruthenium hydride complex-catalyzed N-silylation of primary and secondary amines with substituted vinylsilanes, with the general formula R1CHCHSiR′3 (where R1 = H, Ph, n-Bu, Si(OEt)3), leading to the formation of a Si-