10236-10-9Relevant articles and documents
Measuring the Relative Reactivity of the Carbon–Hydrogen Bonds of Alkanes as Nucleophiles
Olmos, Andrea,Gava, Riccardo,Noverges, Bárbara,Bellezza, Delia,Jacob, Kane,Besora, Maria,Sameera, W. M. Chamil,Etienne, Michel,Maseras, Feliu,Asensio, Gregorio,Caballero, Ana,Pérez, Pedro J.
, p. 13848 - 13852 (2018)
We report quantitative measurements of the relative reactivities of a series of C?H bonds of gaseous or liquid CnH2n+2 alkanes (n=1–8, 29 different C?H bonds) towards in situ generated electrophiles (copper, silver, and rhodium carbenes), with methane as the reference. This strategy surpasses the drawback of previous model reactions of alkanes with strong electrophiles suffering from C?C cleavage processes, which precluded direct comparison of the relative reactivities of alkane C?H bonds.
Functionalization of CnH2n+2 Alkanes: Supercritical Carbon Dioxide Enhances the Reactivity towards Primary Carbon-Hydrogen Bonds
Gava, Riccardo,Olmos, Andrea,Noverges, Bárbara,Varea, Teresa,Funes-Ardoiz, Ignacio,Belderrain, Tomás R.,Caballero, Ana,Maseras, Feliu,Asensio, Gregorio,Pérez, Pedro J.
, p. 3254 - 3260 (2015)
The functionalization of the primary sites of alkanes is one of the more challenging areas in catalysis. In this context, a novel effect has been discovered that is responsible for an enhancement in the reactivity of the primary C-H bonds of alkanes in a catalytic system. The copper complex Cu(NCMe) (=hydrotris{[3,5-bis(trifluoromethyl)-4-bromo]-pyrazol-1-yl}borate) catalyzes the functionalization of CnH2n+2 with ethyl diazoacetate upon inserting the CHCO2Et unit into C-H bonds. In addition, the selectivity of the reaction toward the primary sites significantly increased relative to that obtained in neat alkane upon using supercritical carbon dioxide as the reaction medium. This was attributed to the effect of the carbon dioxide molecules that withdraw electron density from the fluorine atoms of the ligand, which enhances the electrophilic nature of the metal center. DFT studies validated this proposal.
Water as the Reaction Medium for Intermolecular C-H Alkane Functionalization in Micellar Catalysis
álvarez, María,Gava, Riccardo,Rodríguez, Manuel R.,Rull, Silvia G.,Pérez, Pedro J.
, p. 3707 - 3711 (2017)
A series of alkanes CnH2n+2 have been functionalized in water as the reaction medium, using a silver-based catalyst, upon the insertion of carbene (CHCO2Et from N2CHCO2Et) groups into the carbon-hydrogen bonds of hexane, cyclohexane, or 2-methylbutane, among others. The regioselectivity toward the distinct reaction sites is identical to that found in neat alkane, the water-based system allowing the use of a much shorter excess of the hydrocarbon. This is the first example of the intermolecular functionalization of alkanes with this strategy in water. The functionalized alkanes partially undergo the incorporation of a second carbene unit to provide α-(acyloxy)acetates, in an unprecedented tandem reaction of this nature.
Electrochemical cross-coupling of biogenic di-acids for sustainable fuel production
Holzh?user, F. Joschka,Creusen, Guido,Moos, Gilles,Dahmen, Manuel,K?nig, Andrea,Artz, Jens,Palkovits, Stefan,Palkovits, Regina
, p. 2334 - 2344 (2019/05/21)
Direct electrocatalytic conversion of bio-derivable acids represents a promising technique for the production of value-added chemicals and tailor-made fuels from lignocellulosic biomass. In the present contribution, we report the electrochemical decarboxylation and cross-coupling of ethyl hydrogen succinate, methyl hydrogen methylsuccinate and methylhexanoic acid with isovaleric acid. The reactions were performed in aqueous solutions or methanol at ambient temperatures, following the principles of green chemistry. High conversions of the starting materials have been obtained with maximum yields between 42 and 61% towards the desired branched alkane products. Besides costly Pt electrodes also (RuxTi1-x)O2 on Ti electrodes exhibited a notable activity for cross-Kolbe electrolysis. As some of the products are insoluble in water, easy product isolation and reuse of the reaction solvent is enabled via phase separation. Several side products have been identified to evaluate the efficiency of the reaction and to elucidate the factors influencing the product selectivity. The yielded alkanes and esters were assessed with regard to their potential as fuels for internal combustion engines. While the longer alkanes constitute promising candidates for the compression-ignition engine, the smaller ester represents an interesting option for the spark-ignition engine.
Pyrazole derivative and preparation method and application thereof
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Paragraph 0115; 0116, (2016/10/09)
The invention discloses a pyrazole derivative and a preparation method and application thereof. The compound has the structure shown by formula I. The invention further relates to a pharmaceutical composition comprising the compound in the structure of the formula I and application of the compound in preparation of anti-HBV drugs.
Simple, chemoselective hydrogenation with thermodynamic stereocontrol
Iwasaki, Kotaro,Wan, Kanny K.,Oppedisano, Alberto,Crossley, Steven W. M.,Shenvi, Ryan A.
supporting information, p. 1300 - 1303 (2014/02/14)
Few methods permit the hydrogenation of alkenes to a thermodynamically favored configuration when steric effects dictate the alternative trajectory of hydrogen delivery. Dissolving metal reduction achieves this control, but with extremely low functional group tolerance. Here we demonstrate a catalytic hydrogenation of alkenes that affords the thermodynamic alkane products with remarkably broad functional group compatibility and rapid reaction rates at standard temperature and pressure.
Spiro compounds or salts thereof and preventives/remedies for autoimmune diseases and AP-1 inhibitors containing the same
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, (2008/06/13)
The spiro compounds of the present invention represented by the general formula: wherein A, R2, R3, R4, R5, R6and n are as defined in the specification, exhibit an AP-1 activity inhibitory action and, based on the AP-1 inhibitory action, suppresses the expression of a wide variety of genes and are useful as an agent for treating and preventing autoimmune diseases with lessoned side reactions.
Synthesis and pharmacology of the isomeric methylheptyl-Δ8-tetrahydrocannabinols
Huffman, John W.,Liddle, John,Duncan Jr., Sammy G.,Yu, Shu,Martin, Billy R.,Wiley, Jenny L.
, p. 2383 - 2396 (2007/10/03)
The synthesis of the 3-heptyl, and the eleven isomeric 3-methylheptyl-Δ8-tetrahydrocannabinols (3-7, R and S methyl epimers, and 8) has been carried out. The synthetic approach entailed the synthesis of substituted resorcinols, which were subjected to acid catalyzed condensation with trans-para-menthadienol to provide the Δ8-THC analogue. The 1'-, 2'- and 3'-methylheptyl analogues (3-5) are considerably more potent than Δ8-THC. The 4'-, 5'- and 6'-methylheptyl isomers (6-8) are approximately equal in potency to Δ8-THC. Copyright (C) 1998 Elsevier Science Ltd.