- Sustainable System for Hydrogenation Exploiting Energy Derived from Solar Light
-
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.
- Ishida, Naoki,Kamae, Yoshiki,Ishizu, Keigo,Kamino, Yuka,Naruse, Hiroshi,Murakami, Masahiro
-
supporting information
p. 2217 - 2220
(2021/02/16)
-
- Selective Catalytic Hydrogenolysis of Carbon-Carbon σ Bonds in Primary Aliphatic Alcohols over Supported Metals
-
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.
- Di, Lu,Yao, Sikai,Li, Mengru,Wu, Guangjun,Dai, Weili,Wang, Guichang,Li, Landong,Guan, Naijia
-
p. 7199 - 7207
(2015/12/11)
-
- Synthesis of (2-alkylthiothiazolin-5-yl)methyl dodecanoates via tandem radical reaction
-
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.
- Kakaei, Saeed,Xu, Jiaxi
-
p. 5481 - 5490
(2013/08/28)
-
- Electrochemical deoxygenation of primary alcohols
-
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.
- Lam, Kevin,Mark, István E.
-
experimental part
p. 1235 - 1239
(2012/06/18)
-
- Exceptionally high decarboxylation rate of a primary aliphatic acyloxy radical determined by radical product yield analysis and quantitative 1H-CIDNP spectroscopy
-
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
- Fraind, Alicia,Turncliff, Ryan,Fox, Teri,Sodano, Justin,Ryzhkov, Lev R.
-
scheme or table
p. 809 - 820
(2012/06/29)
-
- Efficient heterogeneous dual catalyst systems for alkane metathesis
-
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.
- 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)
-
- Toluates: unexpectedly versatile reagents
-
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.
- Lam, Kevin,Markó, István E.
-
experimental part
p. 10930 - 10940
(2010/02/28)
-
- Organic electrosynthesis using toluates as simple and versatile radical precursors
-
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.
- Lam, Kevin,Marko, Istvan E.
-
experimental part
p. 95 - 97
(2009/03/11)
-
- DEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBONS TO RENDER THEM AVAILABLE FOR BIODEGRADATION
-
A method for the degradation of polycyclic aromatic compounds is disclosed that involves dissolving ozone in a bipolar solvent comprising a non-polar solvent in which is of sufficiently non-polar character to solubilized the polycyclic aromatic compounds, and a polar-water-compatible solvent which is fully miscible with the non-polar solvent to form a single phase with the non-polar solvent. The bipolar solvent with dissolved ozone is contacted with the polycyclic aromatic compounds to solubilize the polycyclic aromatic compounds and react the dissolved polycyclic aromatic compounds with the ozone to degrade the dissolved polycyclic aromatic compounds to oxygenated intermediates. The bipolar solvent is then mixed with sufficient water to form separate non-polar and polar phases, the non-polar phase comprising the non-polar solvent and the polar phase comprising the non-polar solvent and the oxygenated intermediates. The polar phase is then diluted and incubated with bacteria to biodegrade the oxygenated intermediates.
- -
-
Page/Page column 5-8; 15-16
(2008/12/07)
-
- Using toluates as simple and versatile radical precursors
-
(Chemical Equation Presented) The viability of the toluate moiety as a radical precursor has been examined by studying deoxygenation and cyclization reactions.
- Lam, Kevin,Marko, Istvan E.
-
scheme or table
p. 2773 - 2776
(2009/05/30)
-
- Process for hydrogenation of carboxylic acids and derivatives to hydrocarbons
-
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.
- -
-
Page/Page column 7-8
(2008/06/13)
-
- METHOD FOR THE PRODUCTION OF PRIMARY LONG-CHAIN ALCOHOLS
-
The invention relates to a method for the production of linear long-chain alcohols with 20 to 40 carbon atoms by means of a growth reaction with ethylene on aluminium compounds.
- -
-
Page/Page column 8-9
(2010/02/15)
-
- Bruchins - Mitogenic 3-(hydroxypropanoyl) esters of long chain diols from weevils of the bruchidae
-
Mono- and bis 3-(hydroxypropanoyl) esters of long chain, unsaturated diols have been isolated and identified from two genera of the family Bruchidae, and have been shown to be responsible for the mitogenic activity observed on pea pods resulting from oviposition by the pea weevil, Bruchus pisorum. The mitogenic compounds have been characterized and synthesized.
- Oliver, James E,Doss, Robert P,Williamson, R.Thomas,Carney, John R,DeVilbiss, E.David
-
p. 7633 - 7641
(2007/10/03)
-
- Process for the preparation of mono- and bis(phosphocholine) derivatives which have antifungal activity
-
This invention pertains to a synthetic process for obtaining a unique phosphocholine derivative which has been isolated from the leaves of the plant Irbachia alata, identified to be 1,22-bis?2-(trimethylammonium)ethylphosphatyl! docosane is disclosed. Also disclosed is a synthetic process for obtaining a novel class of mono- and bis(phosphocholine) derivatives which are useful as antiinfective agents. The compounds are particularly effective in treating fungal infections, especially those caused by Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus.
- -
-
-
- A convenient one step anodic synthesis of 3-alkyl indoles
-
3-Alkyl indoles have been synthesized anodically by co-electrolysis of indole-3-propanoic acid 1 and mono carboxylic acids 2a-2f viz. propanoic acid 2a, hexanoic acid 2b, nonanoic acid 2c, decanoic acid 2d, dodecanoic acid 2e and hexadecanoic acid 2f at platinum, titanium and graphite. The dimeric products obtained are viz. 1,4 (3′-diindolyl) butane 1′, alkanes 2′a-2′f and 3-alkyl indoles 3′a-3′f. These products have been separated by column chromatography using different solvents and characterized by IR, 1H NMR and elemental analysis. These studies have suggested that the desired product 3′a-3′f is obtained in 33-60% yield at platinum anode at current density 0.1111 A.cm-2.
- Yadav, Ashok K.,Singh, Arpita,Prakash, Lalit
-
p. 1274 - 1278
(2007/10/03)
-
- Radical Nature of Pathways to Alkene and Ester from Thermal Decomposition of Primary Alkyl Diacyl Peroxide
-
Thermal decomposition of a primary alkyl diacyl peroxide 2 is investigated.Dependence of product yields on temperature, viscosity, and solvent polarity is examined in a variety of media.The excess of the alkene disproportionation product 4 and the presence of ester 3 and acid 5 is argued to demonstrate the existence of a discrete acyloxy-alkyl geminate radical pair.Stereoselective deuterium labeling of 2 and subsequent 1H-NMR analysis of the resulting isotopomers of 4 confirm the radical nature of detected decomposition products.
- Ryzhkov, Lev R.
-
p. 2801 - 2808
(2007/10/03)
-
- Composition and process for augmenting, enhancing or imparting a leather aroma to consumable materials
-
Described is the process for augmenting, enhancing or imparting leather aromas to consumable materials including perfume compositions, colognes, perfumed polymers and perfumed articles including solid or liquid anionic, cationic, nonionic or zwitterionic detergents, fabric softener compositions, fabric softener articles, hair preparations, cosmetic powders and the like, by adding thereto a composition of matter consisting of the following ingredients: "A": At least one substance having the structure: STR1 in an amount of from about 1% up to about 5% wherein R9 represents C9 -C11 straight-chain alkyl and wherein R10 represents methyl and X is a moiety selected from the group consisting of: STR2 "B": At least one compound having the structure: STR3 in an amount of from about 3 up to about 7% wherein each of R12 -R15 represents hydrogen or C1 -C4 alkyl with the proviso that at least two of R12 -R15 represents hydrogen; "C": At least one compound having the structure: STR4 in an amount of from about 2% up to about 6% wherein R1, R2, R3, R4 and R5 each represents hydrogen or C1 -C4 alkyl with the proviso that one, two or three of R1, R2, R3, R4 and R5 represents C1 -C4 alkyl; "D": Optionally, at least one compound having the structure: STR5 in an amount of from 0% up to about 1.2% wherein R6 represents hydrogen or methyl and R11 represents hydrogen or methyl with the proviso that at least one of R6 or R11 is hydrogen; "E": At least one compound defined according to the structure: STR6 in an amount of from about 30% up to about 70% wherein R7 represents C11, C13, or C15 straight-chain alkyl and R8 represents C1 -C3 lower alkyl; "F": At least one compound having the structure: STR7 in an amount of from about 20% up to about 60% wherein n represents an integer of from 8 up to 28; "G": Optionally, the compound having the structure: STR8 in an amount of from 0 up to about 6%; and "H": Optionally, the compound having the structure: STR9 in an amount of from 0 up to about 6% with the requirement that: STR10 equal 100%.
- -
-
-
- SELECTIVE MIXED COUPLING OF CARBOXYLIC ACIDS (I). - ELECTROLYSIS, THERMOLYSIS AND PHOTOLYSIS OF UNSYMMETRICAL DIACYL PEROXIDES WITH ACYCLIC AND CYCLIC ALKYL GROUPS
-
14 unsymmetrical diacyl peroxides (R1CO2-O2CR2 with R1: undecyl; R2: e.g. methyl, propyl, pentyl, nonyl, 2-methylpropyl, 2-propyl, 2-pentyl, cyclopropyl, cyclobutyl, cyclohexyl) are prepared in 85 to 92 percent yield.Square pulse electrolysis of dodecanoyl octanoyl peroxide (1i) affords the unsymmetrical coupling product octadecane (4) in poor yield and selectivity.Thermolysis or photolysis in solution produces preferentially 4, but also considerable amounts of disproportionation products.At -78 deg C the neat peroxides are photolysed selectively to the mixed dimers.With straight chain and β-branched alkyl groups high yields are obtained (63 - 76 percent), with cycloalkyl groups medium yields (42 - 56 percent), and with α-branched diacyl peroxides moderate yields (20 - 33 percent).A comparison of the mixed Kolbe-electrolysis with the low temperature photolysis of the neat peroxide demonstrates the superiority of the latter method in small scale conversion with regard to yield and selectivity.
- Feldhues, Michael,Schaefer, Hans J.
-
p. 4195 - 4212
(2007/10/02)
-
- SELECTIVE MIXED COUPLING OF CARBOXYLIC ACIDS VIA UNSYMMETRICAL DIACYL PEROXIDES BY ELECTROLYSIS, THERMOLYSIS AND PHOTOLYSIS
-
Unsymmetrical diacyl peroxides are prepared in 85-92 percent yields.Their square pulse electrolysis affords unsymmetrical dimers in poor yield and selectivity.Whilst thermolysis or photolysis in solution produces high portions of disproportionation products, the photolysis of the neat peroxides at -78 deg C yields selectively 50-75 percent of the mixed dimers.
- Feldhues, Michael,Schaefer, Hans J.
-
p. 433 - 436
(2007/10/02)
-
