26001-58-1Relevant articles and documents
One-Step Bioconversion of Fatty Acids into C8-C9 Volatile Aroma Compounds by a Multifunctional Lipoxygenase Cloned from Pyropia haitanensis
Zhu, Zhu-Jun,Chen, Hai-Min,Chen, Juan-Juan,Yang, Rui,Yan, Xiao-Jun
, p. 1233 - 1241 (2018/02/19)
The multifunctional lipoxygenase PhLOX cloned from Pyropia haitanensis was expressed in Escherichia coli with 24.4 mg·L-1 yield. PhLOX could catalyze the one-step bioconversion of C18-C22 fatty acids into C8-C9 volatile organic compounds (VOCs), displaying higher catalytic efficiency for eicosenoic and docosenoic acids than for octadecenoic acids. C20:5 was the most suitable substrate among the tested fatty acids. The C8-C9 VOCs were generated in good yields from fatty acids, e.g., 2E-nonenal from C20:4, and 2E,6Z-nonadienal from C20:5. Hydrolyzed oils were also tested as substrates. The reactions mainly generated 2E,4E-pentadienal, 2E-octenal, and 2E,4E-octadienal from hydrolyzed sunflower seed oil, corn oil, and fish oil, respectively. PhLOX showed good stability after storage at 4 °C for 2 weeks and broad tolerance to pH and temperature. These desirable properties of PhLOX make it a promising novel biocatalyst for the industrial production of volatile aroma compounds.
Bis(imino)pyridine cobalt-catalyzed dehydrogenative silylation of alkenes: Scope, mechanism, and origins of selective allylsilane formation
Atienza, Crisita Carmen Hojilla,Diao, Tianning,Weller, Keith J.,Nye, Susan A.,Lewis, Kenrick M.,Delis, Johannes G. P.,Boyer, Julie L.,Roy, Aroop K.,Chirik, Paul J.
supporting information, p. 12108 - 12118 (2014/10/16)
The aryl-substituted bis(imino)pyridine cobalt methyl complex, ( MesPDI)CoCH3 (MesPDI = 2,6-(2,4,6-Me 3C6H2-N=CMe)2C5H 3N), promotes the catalytic dehydrogenative silylation of linear α-olefins to selectively form the corresponding allylsilanes with commercially relevant tertiary silanes such as (Me3SiO) 2MeSiH and (EtO)3SiH. Dehydrogenative silylation of internal olefins such as cis- and trans-4-octene also exclusively produces the allylsilane with the silicon located at the terminus of the hydrocarbon chain, resulting in a highly selective base-metal-catalyzed method for the remote functionalization of C-H bonds with retention of unsaturation. The cobalt-catalyzed reactions also enable inexpensive α-olefins to serve as functional equivalents of the more valuable α, ω-dienes and offer a unique method for the cross-linking of silicone fluids with well-defined carbon spacers. Stoichiometric experiments and deuterium labeling studies support activation of the cobalt alkyl precursor to form a putative cobalt silyl, which undergoes 2,1-insertion of the alkene followed by selective β-hydrogen elimination from the carbon distal from the large tertiary silyl group and accounts for the observed selectivity for allylsilane formation.
Homogeneous Pd-catalyzed transformation of terminal alkenes into primary allylic alcohols and derivatives
Tomita, Ren,Mantani, Kohei,Hamasaki, Akiyuki,Ishida, Tamao,Tokunaga, Makoto
supporting information, p. 9914 - 9917 (2014/08/18)
Synthesis of primary alcohols from terminal alkenes is an important process in both bulk and fine chemical syntheses. Herein, a homogeneous Pd-complex-catalyzed transformation of terminal alkenes into primary allylic alcohols, by using 5 mol % [Pd(PPh3)4] as a catalyst, and H2O, CO2, and quinone derivatives as reagents, is reported. When alcohols were used instead of H2O, allylic ethers were obtained. A proposed mechanism includes the addition of oxygen nucleophiles at the less-hindered terminal position of π-allyl Pd intermediates.
Multistep enzymatic synthesis of long-chain α,ω-Dicarboxylic and ω-hydroxycarboxylic acids from renewable fatty acids and plant oils
Song, Ji-Won,Jeon, Eun-Yeong,Song, Da-Hyun,Jang, Hyun-Young,Bornscheuer, Uwe T.,Oh, Deok-Kun,Park, Jin-Byung
supporting information, p. 2534 - 2537 (2013/04/23)
A multistep enzyme catalysis was successfully implemented to produce long-chain α,ω-dicarboxylic and ω-hydroxycarboxylic acids from renewable fatty acids and plant oils. Sebacic acid as well as ω-hydroxynonanoic acid and ω-hydroxytridec-11-enoic acid were produced from oleic and ricinoleic acid. Copyright
Investigating inner-sphere reorganization via secondary kinetic isotope effects in the C-H cleavage reaction catalyzed by soybean lipoxygenase: Tunneling in the substrate backbone as well as the transferred hydrogen
Meyer, Matthew P.,Klinman, Judith P.
supporting information; experimental part, p. 430 - 439 (2011/04/16)
This work describes the application of NMR to the measurement of secondary deuterium (2° 2H) and carbon-13 (13C) kinetic isotope effects (KIEs) at positions 9-13 within the substrate linoleic acid (LA) of soybean lipoxygenase-1. The KIEs have been measured using LA labeled with either protium (11,11- h2-LA) or deuterium (11,11-d2-LA) at the reactive C11 position, which has been previously shown to yield a primary deuterium isotope effect of ca. 80. The conditions of measurement yield the intrinsic 2° 2H and 13C KIEs on kcat/Km directly for 11,11-d2-LA, whereas the values for the 2° 2H KIEs for 11,11-h2-LA are obtained after correction for a kinetic commitment. The pattern of the resulting 2° 2H and 13C isotope effects reveals values that lie far above those predicted from changes in local force constants. Additionally, many of the experimental values cannot be modeled by electronic effects, torsional strain, or the simple inclusion of a tunneling correction to the rate. Although previous studies have shown the importance of extensive tunneling for cleavage of the primary hydrogen at C11 of LA, the present findings can only be interpreted by extending the conclusion of nonclassical behavior to the secondary hydrogens and carbons that flank the position undergoing C-H bond cleavage. A quantum mechanical method introduced by Buhks et al. [J. Phys. Chem. 1981, 85, 3763] to model the inner-sphere reorganization that accompanies electron transfer has been shown to be able to reproduce the scale of the 2° 2H KIEs.
Regioselective SN2 opening of vinylic epoxides with trialkylzincates and trialkylaluminates
Equey, Olivier,Vrancken, Emmanuel,Alexakis, Alexandre
, p. 2151 - 2159 (2007/10/03)
The use of trialkylorganozincates and tetraalkylaluminates allows regioselective SN2 nucleophilic opening of vinylic epoxides. The reaction occurs with an anti-substitution pattern and can be applied to a wide range of substrates. We also show that the solvent and the structure of the epoxide have an influence on the substitution products' ratio. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Catalytic Regiodivergent Kinetic Resolution of Allylic Epoxides: A New Entry to Allylic and Homoallylic Alcohols with High Optical Purity
Pineschi, Mauro,Del Moro, Federica,Crotti, Paolo,Di Bussolo, Valeria,Macchia, Franco
, p. 2099 - 2105 (2007/10/03)
A novel regiodivergent kinetic resolution of a series of allylic epoxides with alkylzinc reagents is described. Results demonstrate the potential of chiral copper-phosphoramidite catalysts for enantiomer differentiation of allylic epoxides, allowing a chiral catalyst-stereoregulated synthesis of cyclic allylic and homoallylic alcohols with high optical purities.
EXO- AND ENDOHORMONES, XVI SYNTHESIS OF (4E, 7Z)-4,7-TRIDECADIEN 1-YL ACETATE, THE SEX PHEROMONE FOR THE LEAFMINER LITHOCOLLETIS CORYLIFOLIELLA
Gocan, Alexandra,Gansca, Lucia,Oprean, Ioan
, p. 253 - 258 (2007/10/03)
The synthesis of the sex pheromone of the leafminer moth, Lithocolletis corylifoliella, (4E, 7Z)-4,7-tridecadien-1-yl acetate, was based on a C5+C8 scheme.The coupling reaction took place between the Grignard reagent of 4-pentin-1-1-oic acid and 1-bromo-2Z-octene.Propargylic alcohol was used as a starting material in order to obtain the two synthons.
The reaction of trimethylsilyl ethylene oxide with α-sulfonyl anions and α,α-sulfonyl dianions. A method for stereocontrolled synthesis of (E)- and (Z)-allylic alcohols
Jankowski, Pawel,Marczak, Stanislaw,Masnyk, Marek,Wicha, Jerzy
, p. 49 - 62 (2007/10/02)
Trimethylsilyl ethylene oxide has been shown to react with α-sulfonyl carbanions generated from representative primary alkyl phenyl sulfones to give the corresponding O-trimethylsilyl allylic alcohols, with higher selectivity for (Z)-isomers.The reaction proceeds by attachment of the nucleophile to the α-position of the α,β-epoxyalkylsilane followed by a carbon-to-oxygen shift of the trimethylsilyl group and expulsion of the benzenosulfonyl anion.The reaction of trimethylsilyl ethylene oxide with α,α-sulfonyl dianions followed by partial protonation of the immediate adducts affords O-trimethylsilyl allylic alcohols, mainly (E)-isomers.The reaction of trimethylsilyl ethylene oxide with α-sulfonyl carbanions generated from secondary alkyl phenyl sulfones affords α-trimethylsilyl carbinols as the only or predominant product.In this case the attachment of the nucleophile takes place at the β-position of the α,β-epoxyalkylsilane.The origin of the regio- and stereo-selectivity in reactions of sulfonyl carbanions with α,β-epoxyalkylsilanes is discussed.
NICKEL(II)-CATALYZED ALKYLATION OF 2-METHYL-1,3-DIOXEP-4-ENE BY GRIGNARD REAGENTS: AN EFFICIENT AND SELECTIVE ROUTE TO ALLYLIC ALCOHOLS
Menicagli, Rita,Malanga, Corrado,Finato, Barbara,Lardicci, Luciano
, p. 69 - 70 (2007/10/02)
Allylic alcohols are formed, in good yields, through the regiocontrolled Cl2Nidppe-catalyzed alkylation of 2-methyl-1,3-dioxep-4-ene by Grignard reagents .Highly pure Z alcohols arise when secondary and tertiary aliphatic Grignards are used.
