629-97-0Relevant academic research and scientific papers
Sustainable System for Hydrogenation Exploiting Energy Derived from Solar Light
Ishida, Naoki,Kamae, Yoshiki,Ishizu, Keigo,Kamino, Yuka,Naruse, Hiroshi,Murakami, Masahiro
supporting information, p. 2217 - 2220 (2021/02/16)
Herein described is a sustainable system for hydrogenation that uses solar light as the ultimate source of energy. The system consists of two steps. Solar energy is captured and chemically stored in the first step; exposure of a solution of azaxanthone in ethanol to solar light causes an energy storing dimerization of the ketone to produce a sterically strained 1,2-diol. In the second step, the chemical energy stored in the vicinal diol is released and used for hydrogenation; the diol offers hydrogen onto alkenes and splits back to azaxanthone, which is easily recovered and reused repeatedly for capturing solar energy.
Selective Catalytic Hydrogenolysis of Carbon-Carbon σ Bonds in Primary Aliphatic Alcohols over Supported Metals
Di, Lu,Yao, Sikai,Li, Mengru,Wu, Guangjun,Dai, Weili,Wang, Guichang,Li, Landong,Guan, Naijia
, p. 7199 - 7207 (2015/12/11)
The selective scission of chemical bonds is always of great significance in organic chemistry. The cleavage of strong carbon-carbon σ bonds in the unstrained systems remains challenging. Here, we report the selective hydrogenolysis of carbon-carbon σ bonds in primary aliphatic alcohols catalyzed by supported metals under relatively mild conditions. In the case of 1-hexadecanol hydrogenolysis over Ru/TiO2 as a model reaction system, the selective scission of carbon-carbon bonds over carbon-oxygen bonds is observed, resulting in n-pentadecane as the dominant product with a small quantity of n-hexadecane. Theoretical calculations reveal that the 1-hexadecanol hydrogenolysis on flat Ru (0001) undergoes two parallel pathways: i.e. carbon-carbon bond scission to produce n-pentadecane and carbon-oxygen bond scission to produce n-hexadecane. The removal of adsorbed CO on a flat Ru (0001) surface is a crucial step for the 1-hexadecanol hydrogenolysis. It contributes to the largest energy barrier in n-pentadecane production and also retards the rate for n-hexadecane production by covering the active Ru (0001) surface. The knowledge presented in this work has significance not just for a fundamental understanding of strong carbon-carbon σ bond scission but also for practical biomass conversion to fuels and chemical feedstocks.
Synthesis of (2-alkylthiothiazolin-5-yl)methyl dodecanoates via tandem radical reaction
Kakaei, Saeed,Xu, Jiaxi
, p. 5481 - 5490 (2013/08/28)
A series of (2-alkylthiothiazolin-5-yl)methyl dodecanoates was synthesized from various alkyl N-allylcarbamodithioates and dilauroyl peroxide via a tandem radical hydrogen-abstraction-cyclization-substitution/combination reaction with a 5-exo-trig radical cyclization as a key step. The current route is the first, convenient, and efficient synthesis of (2-alkylthiothiazolin-5-yl)methanol derivatives. The Royal Society of Chemistry.
Electrochemical deoxygenation of primary alcohols
Lam, Kevin,Mark, István E.
experimental part, p. 1235 - 1239 (2012/06/18)
Direct electrolysis of primary alcohols, in the presence of methyl toluate, leads smoothly to the formation of the corresponding deoxygenated product in high yield. Georg Thieme Verlag Stuttgart · New York.
Exceptionally high decarboxylation rate of a primary aliphatic acyloxy radical determined by radical product yield analysis and quantitative 1H-CIDNP spectroscopy
Fraind, Alicia,Turncliff, Ryan,Fox, Teri,Sodano, Justin,Ryzhkov, Lev R.
scheme or table, p. 809 - 820 (2012/06/29)
Symmetrical (RCO2CO2R; R=XCH2CH 2) and asymmetrical (RCO2CO2R′; R=C 9H19CH2CH2, R′=CH3 or m-ClC6H4) primary diacyl peroxides were thermally decomposed under different conditions to analyze the decarboxylation rates of the thermally generated acyloxy radicals. Quantitative models of the geminate product yields, and qualitative and quantitative 1H-CIDNP spectroscopy were used to obtain the decarboxylation rate estimates. Results reported here suggest that, unlike short chain acyloxy radicals such as propanoyloxyl, long chain acyloxy radicals possess the highest decarboxylation rates of all known acyloxy radicals, estimated at (0.5-1.5)× 10 12s-1 between 80 and 140°C. Given the nature of the dissociative state of acyloxy radicals, such rates appear to be the result of destabilization of the former by the steric bulk of the long chain substituents. Additionally, the rate of this order of magnitude suggests a nearly concerted decarboxylation of primary diacyl peroxides. Copyright
Efficient heterogeneous dual catalyst systems for alkane metathesis
Huang, Zheng,Rolfe, Eleanor,Carson, Emily C.,Brookhart, Maurice,Goldman, Alan S,El-Khalafy, Sahar H.,Roy MacArthur, Amy H.
experimental part, p. 125 - 135 (2010/06/20)
A fully heterogeneous and highly efficient dual catalyst system for alkane metathesis (AM) has been developed. The system is comprised of an alumina-supported iridium pincer catalyst for alkane dehydrogenation/olefin hydrogenation and a second heterogeneous olefin metathesis catalyst. The iridium catalysts bear basic functional groups on the aromatic backbone of the pincer ligand and are strongly adsorbed on Lewis acid sites on alumina. The heterogeneous systems exhibit higher lifetimes and productivities relative to the corresponding homogeneous systems as catalyst/catalyst interactions and bimolecular decomposition reactions are inhibited. Additionally, using a two-pot device, the supported Ir catalysts and metathesis catalysts can be physically separated and run at different temperatures. This system with isolated catalysts shows very high turnover numbers and is selective for the formation of high molecular weight alkanes.
Toluates: unexpectedly versatile reagents
Lam, Kevin,Markó, István E.
experimental part, p. 10930 - 10940 (2010/02/28)
The mechanism of the monoelectronic reduction of aromatic esters has been investigated. The unexpected synthetic utility of the toluate moiety in the deoxygenation of alcohols and the allylation of ketones is also reported. Finally, the use of aromatic esters as robust, though easily removable, protecting groups is depicted.
Organic electrosynthesis using toluates as simple and versatile radical precursors
Lam, Kevin,Marko, Istvan E.
experimental part, p. 95 - 97 (2009/03/11)
The electrolysis of toluate esters leads smoothly to the formation of the radical of the alkyl fragment. This property has been used to develop a new electrochemical deoxygenation reaction. The Royal Society of Chemistry.
Process for hydrogenation of carboxylic acids and derivatives to hydrocarbons
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Page/Page column 7-8, (2008/06/13)
A process for hydrogenating a carboxylic acid and/or derivative thereof having a carboxylate group represented by the general formula R1COO-, which process comprises feeding hydrogen and the carboxylic acid and/or derivative thereof to a reactor and maintaining conditions within the reactor such that hydrogen reacts with the carboxylic acid and/or derivative thereof to produce a product stream comprising carbon dioxide, carbon monoxide, methane and hydrocarbons represented by general formulae R1H and R1CH3, characterised in that the molar ratio of R1H : R1CH3 is above a pre-determined value and/or the mole ratio of the sum of carbon dioxide, carbon monoxide and methane to carboxylate groups is above a pre-determined value.
Using toluates as simple and versatile radical precursors
Lam, Kevin,Marko, Istvan E.
scheme or table, p. 2773 - 2776 (2009/05/30)
(Chemical Equation Presented) The viability of the toluate moiety as a radical precursor has been examined by studying deoxygenation and cyclization reactions.
