- Expansion of substrate scope for nitroxyl radical/copper-catalyzed aerobic oxidation of primary alcohols: A guideline for catalyst selection
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Four distinctive sets of optimum nitroxyl radical/copper salt/additive catalyst combinations have been identified for accommodating the aerobic oxidation of various types of primary alcohols to their corresponding aldehydes. Interestingly, less nucleophilic catalysts exhibited higher catalytic activities for the oxidation of particular primary allylic and propargylic alcohols to give α,β-unsaturated aldehydes that function as competent Michael acceptors. The optimum conditions identified herein were successful in the oxidation of various types of primary alcohols, including unprotected amino alcohols and divalent-sulfur-containing alcohols in good-to-high yields. Moreover, N-protected alaninol, an inefficient substrate in the nitroxyl radical/ copper-catalyzed aerobic oxidation, was oxidized in good yield. On the basis of the optimization results, a guideline for catalyst selection has been established.
- Iwabuchi, Yoshiharu,Nagasawa, Shota,Sasaki, Ryota,Sasano, Yusuke,Yamaichi, Aoto
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p. 488 - 497
(2021/05/27)
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- A Method for preparing alpha-olefins from Biomass-derived fat and oil
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The present invention relates to a method for preparing alpha-olefins from biomass-derived fats and oils. According to the preparation method, all of the various saturated or unsaturated fatty acids in the biomass-derived fats and oils can be prepared into alpha-olefins, and a conventional problem that the saturated fatty acids do not participate in a reaction or a mixture is generated due to polyunsaturated fatty acids can be solved. Thus, the present invention can be advantageously used to prepare alpha-olefins from biomass.
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-
Paragraph 0145; 0158-0161
(2020/09/22)
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- The Catalytic Asymmetric Mukaiyama–Michael Reaction of Silyl Ketene Acetals with α,β-Unsaturated Methyl Esters
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α,β-Unsaturated esters are readily available but challenging substrates to activate in asymmetric catalysis. We now describe an efficient, general, and highly enantioselective Mukaiyama–Michael reaction of silyl ketene acetals with α,β-unsaturated methyl esters that is catalyzed by a silylium imidodiphosphorimidate (IDPi) Lewis acid.
- Gatzenmeier, Tim,Kaib, Philip S. J.,Lingnau, Julia B.,Goddard, Richard,List, Benjamin
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supporting information
p. 2464 - 2468
(2018/02/06)
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- COMPOUNDS FOR USE AS AN ANTI-BACTERIAL OR ANTI-FUNGAL AGENT AND AS A ZINC SENSOR
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The present invention relates to a compound, which can be used as an anti-bacterial and/or an anti-fungal agent as well as a zinc sensor. Moreover, the present invention relates to a pharmaceutical composition comprising said compound and methods for treating bacterial or fungal infections in mammals.
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- Pheromone synthesis. Part 257: Synthesis of methyl (2E,4Z,7Z)-2,4,7-decatrienoate and methyl (E)-2,4,5-tetradecatrienoate, the pheromone components of the male dried bean beetle, Acanthoscelides obtectus (Say)
-
Tandem Dess-Martin oxidation/Wittig reaction of (2Z,5Z)-2,5-octadien-1-ol yielded methyl (2E,4Z,7Z)-2,4,7-decatrienoate, a newly discovered pheromone component of the male dried bean beetle, while that of (±)-2,3-dodecadien-1-ol gave (±)-methyl (E)-2,4,5-tetradecatrienoate, the racemate of the known and major pheromone component. Methyl (2E,4E,7Z)-2,4,7-decatrienoate was also synthesized, which is the methyl ester of an acid metabolite of a green alga. Reduction of 2,5-octadiyn-1-ol with Zn-Cu/EtOH cleanly gave (2Z,5Z)-2,5-octadien-1-ol.
- Mori, Kenji
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supporting information
p. 5589 - 5596
(2015/08/03)
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- Agent having neurotrophic factor-like activity
-
The present invention provides a pharmaceutical agent having high safety and a neurotrophic factor-like activity, which contains, as an active ingredient, any one compound included in fatty acids each having 8 carbon atoms (C8) or having 10 carbon atoms (C10) to 12 carbon atoms (C12) or fatty acid esters thereof, such as 3,7-dimethyloctanoic acid ethyl ester, geranicacidethyl ester, and the like, eachof whichhas 8 carbonatoms (C8), decanoic acid methyl ester, trans-2-decenoic acid, trans-2-decenoic acid methyl ester, trans-2-decenoic acid ethyl ester, trans-2-decenoic acid-2-decenyl ester, trans-2-decenoic acid cyclohexyl ester, trans-2-decenoic acid isopropyl ester, trans-3-decenoic acid methyl ester, trans-9-decenoic acid methyl ester, and the like, each of which has 10 carbon atoms (C10), trans-10-undecenoic acid methyl ester, trans-10-undecenoic acid ethyl ester, and the like, each of which has 11 carbon atoms (C11), and dodecanoic acid, and the like, each of which has 12 carbon atoms (C12), or salts thereof or prodrugs thereof.
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Paragraph 0029-0030
(2016/01/25)
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- N-heterocyclic carbene-catalyzed radical reactions for highly enantioselective β-hydroxylation of enals
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An N-heterocyclic carbene-catalyzed β-hydroxylation of enals is developed. The reaction goes through a pathway involving multiple radical intermediates, as supported by experimental observations. This oxidative single-electron-transfer reaction allows for highly enantioselective access to β-hydroxyl esters that are widely found in natural products and bioactive molecules.
- Zhang, Yuexia,Du, Yu,Huang, Zhijian,Xu, Jianfeng,Wu, Xingxing,Wang, Yuhuang,Wang, Ming,Yang, Song,Webster, Richard D.,Chi, Yonggui Robin
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supporting information
p. 2416 - 2419
(2015/03/04)
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- Characterization of FabG and FabI of the Streptomyces coelicolor dissociated fatty acid synthase
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Streptomyces coelicolor produces fatty acids for both primary metabolism and for biosynthesis of the secondary metabolite undecylprodiginine. The first and last reductive steps during the chain elongation cycle of fatty acid biosynthesis are catalyzed by FabG and FabI. The S. coelicolor genome sequence has one fabI gene (SCO1814) and three likely fabG genes (SCO1815, SCO1345, and SCO1846). We report the expression, purification, and characterization of the corresponding gene products. Kinetic analyses revealed that all three FabGs and FabI are capable of utilizing both straight and branched-chain β-ketoacyl-NAC and enoyl-NAC substrates, respectively. Furthermore, only SCO1345 differentiates between ACPs from both biosynthetic pathways. The data presented provide the first experimental evidence that SCO1815, SCO1346, and SCO1814 have the catalytic capability to process intermediates in both fatty acid and undecylprodiginine biosynthesis.
- Singh, Renu,Reynolds, Kevin A.
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p. 631 - 640
(2015/03/31)
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- A convenient synthesis of (E)-α,β-unsaturated esters with total stereoselectivity promoted by catalytic samarium diiodide
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Synthesis of (E)-α,β-unsaturated esters in high yields and with total stereoselectivity is achieved from α-halo-β-hydroxy esters promoted by catalytic amounts of SmI2. The starting compounds were easily prepared from α-halo esters and aldehydes as a mixture of stereoisomers. A mechanism is proposed to explain this samarium(II)-promoted catalytic β-elimination reaction. Georg Thieme Verlag Stuttgart.
- Concellón, José M.,Rodríguez-Solla, Humberto,Concellón, Carmen,Díaz-Pardo, Ainhoa,Llavona, Ricardo
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experimental part
p. 262 - 264
(2011/03/21)
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- AGENT HAVING NEUROTROPHIC FACTOR-LIKE ACTIVITY
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The present invention provides a pharmaceutical agent having high safety and a neurotrophic factor-like activity, which contains, as an active ingredient, any one compound included in fatty acids each having 8 carbon atoms (C8) or having 10 carbon atoms (C10) to 12 carbon atoms (C12) or fatty acid esters thereof, such as 3,7-dimethyloctanoic acid ethyl ester, geranicacidethyl ester, and the like, eachof whichhas 8 carbonatoms (C8), decanoic acid methyl ester, trans-2-decenoic acid, trans-2-decenoic acid methyl ester, trans-2-decenoic acid ethyl ester, trans-2-decenoic acid-2-decenyl ester, trans-2-decenoic acid cyclohexyl ester, trans-2-decenoic acid isopropyl ester, trans-3-decenoic acid methyl ester, trans-9-decenoic acid methyl ester, and the like, each of which has 10 carbon atoms (C10), trans-10-undecenoic acid methyl ester, trans-10-undecenoic acid ethyl ester, and the like, each of which has 11 carbon atoms (C11), and dodecanoic acid, and the like, each of which has 12 carbon atoms (C12), or salts thereof or prodrugs thereof.
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- Total structure and inhibition of tumor cell proliferation of laxaphycins
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From a mixed assemblage of Lyngbya majuscula rich marine cyanobacteria, we isolated a series of cell growth inhibitory cyclic peptides, The structures of the two major components, laxaphycins A (1) and B (2), and of two minor peptides, laxaphycins B2 (3) and B3 (4), were determined by spectroscopic methods and degradative analysis. Absolute configurations of natural and nonproteinogenic amino acids were determined by a combination of hydrolysis, synthesis of noncommercial residues, chemical derivatization, and HPLC analysis. The organism producing the laxaphycins was identified as the cyanobacterium Anabaena torulosa. The antiproliferative activity of laxaphycins was investigated on a panel of solid and lymphoblastic cancer cells. Our results demonstrate that in contrast to laxaphycin A, laxaphycin B inhibits the proliferation of sensitive and resistant human cancer cell lines and that this activity is strongly increased in the presence of laxaphycin A. This effect appears to be due to an unusual biological synergism.
- Bonnard, Isabelle,Rolland, Marc,Salmon, Jean-Marie,Debiton, Eric,Barthomeuf, Chantal,Banaigs, Bernard
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p. 1266 - 1279
(2007/10/03)
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- Wittig reactions in water media employing stabilized ylides with aldehydes. Synthesis of α,β-unsaturated esters from mixing aldehydes, α-bromoesters, and Ph3P in aqueous NaHCO3
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(Chemical Equation Presented) Water is demonstrated to be an effective medium for the Wittig reaction over a wide range of stabilized ylides and aldehydes. Despite sometimes poor solubility of the reactants, good chemical yields normally ranging from 80 to 98% and high E-selectivities (up to 99%) are achieved, and the rate of the reactions in water is unexpectedly accelerated. The efficiency of water as a medium in the Wittig reaction is compared to conventional organic solvents ranging from carbon tetrachloride to methanol. The aqueous Wittig reaction works best when large hydrophobic entities are present, such as aromatic, heterocyclic aromatic carboxaldehydes, and long-chain aliphatic aldehydes with triphenylphosphoranes. The E/Z-isomeric ratio of the Wittig products appears dependent on the electron-accepting/donating capacity and the location of the substituents present in the aromatic ring. The effect of additives, such as benzoic acid, LiCl, and sodium dodecyl sulfate (SDS), on the Wittig reaction has been explored. The Wittig reaction can also be conducted in the presence of acidic entities, such as phenols and carboxylic acids. In addition, large α-substituents in the aliphatic aldehydes do not jeopardize the reaction. It is also demonstrated that hydrates of aldehydes can be used directly in the aqueous Wittig reaction as substrates. The scope of the aqueous Wittig reaction is extended to 24 examples of one-pot mixtures of Ph3P, α-bromoesters, and aldehydes in sodium bicarbonate solution (at 20°C for 40 min to 3 h) to provide Wittig products of up to 99% yield and up to 98% E-selectivity. Since water is inexpensive, extremely easy to handle, and represents no environmental concerns, it should be considered a possible medium for new organic reactions.
- El-Batta, Amer,Jiang, Changchun,Zhao, Wen,Anness, Robert,Cooksy, Andrew L.,Bergdahl, Mikael
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p. 5244 - 5259
(2008/02/07)
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- An efficient synthesis of (E)-α,β-unsaturated ketones and esters with total stereoselectivity by using chromium dichloride
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(E)-α,β-Unsaturated ketones 1 or esters 2 can be obtained with complete stereoselectivity by reaction of different 2-chloro-3-hydroxy ketones 3 or esters 4 and CrCl2. A comparative study of the results of synthesis of ketones 1 with CrCl2 or samarium is performed. A mechanism to explain both β-elimination reactions has been proposed.
- Concellón, José M.,Rodríguez-Solla, Humberto,Méjica, Carmen
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p. 3292 - 3300
(2007/10/03)
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- Synthesis of (E)-α,β-unsaturated esters with total diastereoselectivity by using chromium dichloride
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Synthesis of di- and trisubstituted (E)-α,β-unsaturated esters is easily achieved by using chromium dichloride through an elimination reaction of a diastereoisomeric mixture of α-halo-β-hydroxy esters. The starting materials were easily prepared by the aldol reaction of lithium enolates of α-chloroesters with aldehydes. A mechanism to explain this elimination process is proposed.
- Concellón, José M.,Rodríguez-Solla, Humberto,Méjica, Carmen
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p. 2977 - 2979
(2007/10/03)
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- Asymmetric synthesis of (-)-acaterin
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The asymmetric synthesis of (-)-acaterin, an inhibitor of acyl-CoA cholesterol acyl transferase has been achieved starting from the commercially available starting materials, octan-1-ol and methyl (R)-lactate. The key steps are a Sharpless asymmetric dihydroxylation and a Wittig olefination.
- Kandula, Subba Rao V.,Kumar, Pradeep
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p. 6149 - 6151
(2007/10/03)
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- Synthesis of (E)-α,β-unsaturated esters and (Z)-vinyl halides with total or high diastereoselectivity by using samarium metal
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A highly diastereoselective β-elimination of 2-halo-3-hydroxy esters 1 or O-acetylated 1,1-dihaloalkan-2-ols 4 is achieved with samarium in the presence of diiodomethane, yielding α,β-unsaturated esters 2 or vinyl halides 5, respectively. The β-elimination reaction was promoted by samarium diiodide, which was generated in situ. The starting halohydrins 1 or 4 are easily prepared by reaction of the corresponding lithium enolates of α-halo esters or dihalomethyllithium with aldehydes at -78°C. The influence of the reaction conditions and the structure of the starting compounds on the diastereoselectivity of the β-elimination reactions is discussed, A comparative study of the β-elimination reaction with preformed SmI2 and metallic samarium is also performed. These elimination reactions can be explained by the proposed mechanism. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).
- Concellon, Jose M.,Rodriguez-Solla, Humberto,Huerta, Monica,Perez-Andres, Juan A.
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p. 1839 - 1847
(2007/10/03)
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- Pd(II) - dppb and syngas catalyze regioselective hydroesterification of terminal alkynes under neutral conditions
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Palladium(II) regioselectively catalyzes the hydroesterification of terminal alkynes under syngas forming α,β-unsaturated esters 3 and 4 in excellent chemical yields under neutral conditions. The high selectivity for the linear ester 4 was obtained with a catalytic system that includes Pd(II), 1,4-bis(diphenylphosphino)butane (dppb) and CO/H2 in CH2Cl2 as solvent. The control of the regioselectivity depends strongly upon the type of ligand, the solvent and the use of the syngas mixture.
- El Ali, Bassam,Tijani, Jimoh,El-Ghanam, Abdel Moneim
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p. 2385 - 2387
(2007/10/03)
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- Synthesis of (E)-a,β-unsaturated esters and amides with total selectivity using samarium diiodide
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β-elimination of α-halo-β-hydroxyesters 1 was achieved by using samarium diiodide as a metalating reagent, and afforded di- and trisubstituted (E)-α,βunsaturated esters 2 with total steroselectivity. This method has also been extended to the corresponding disubstituted (E)-α,β-unsaturated amides.
- Concellon, Jose M.,Perez-Andres, Juan A.,Rodriguez-Solla, Humberto
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p. 2773 - 2775
(2007/10/03)
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- The first low molecular weight antibiotic from lactic acid bacteria: Reutericyclin, a new tetramic acid
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The first chemical proof is available to show that lactic acid bacteria, generally known for their limited metabolite spectrum, are able to produce antibiotics with a broad inhibitory spectrum. The new tetramic acid, reutericyclin (1), opens a new dimension in the discussion regarding the application of lactic acid bacteria in food preservation or for positively influencing the human intestinal microflora.
- Hoeltzel, Alexandra,Gaenzle, Michael G.,Nicholson, Graeme J.,Hammes, Walter P.,Jung, Guenther
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p. 2766 - 2768
(2007/10/03)
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- An efficient and selective conversion of hydrazides into esters and acids
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Hydrazides are selectively oxidised to esters/acids in high yields using Oxone in the presence of an appropriate alcohol/water as a nucleophile at ambient temperature. A variety of functional groups including alkenes, alcohols, ethers, cyclopropyl groups and nitriles are unaffected.
- Srinivas,Subba Reddy,Yadav,Ramalingam
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p. 376 - 377
(2007/10/03)
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- Highly cis-selective Horner-Wadsworth-Emmons (HWE) reaction of methyl bis(2,4-difluorophenyl) phosphonoacetate
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Of the previously reported Homer-Wadsworth-Emmons (HWE) reaction, the olefination of methyl bis(2,4-difluorophenyl)phosphonoacetate (1a) with various aldehydes gave unsaturated esters in the highest cis-selectivity.
- Kokin, Keisuke,Motoyoshiya, Jiro,Hayashi, Sadao,Aoyama, Hiromu
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p. 2387 - 2392
(2007/10/03)
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- Electronic effects on the Z(cis)-selectivity of Horner-Wadsworth-Emmons olefination reaction
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Various phosphorates have been synthesized to study the Horner-Wadsworth-Emmons olefination reaction. The phosphoryl stabilised carbanion resulting from phosphonates, carrying electron withdrawing groups attached to phosphorus atom, has been reacted with a variety of aldehydes at - 78°C leading to Z(cis) selective olefination.
- Mahipal Reddy,Raj Gopal,Jayathirtha Rao
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p. 312 - 317
(2007/10/03)
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- A versatile and convenient protocol for the stereocontrolled synthesis of olefinic insect pheromones
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A combination of the Horner-Emmons synthesis of alkyl 2,4-dienoates with their hydrogenation over complex L·Cr(CO)3 catalysts (L = 3CO or arene) provides a versatile, stereocontrolled and operationally simple approach to the (Z)-disubstituted, (Z)-trisubstituted, (E)-trisubstituted alkenes and skipped (Z,Z)-disubstituted diolefins with a homoallylic type of function. This protocol, sometimes supplemented by an enzymatic hydrolysis, was successfully applied to the synthesis of configurationally pure (gp ≥ 98%) pheromones of the furniture carpet beetle, dry bean beetle, rusty grain beetle, square-necked grain beetle and of a trail-following pheromone mimic for subterranean termites
- Vasil'ev, Andrei A.,Vlasyuk, Alexei L.,Gamalevich, Galina D.,Serebryakov, Edward P.
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p. 389 - 400
(2007/10/03)
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- Synthesis of (±)tetrahydromyricoidine
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A total synthesis of the spermidine alkaloid (±)-tetrahydromyricoidine (6) was achieved by using two ring enlargement reactions. The difficulties experienced in the second ring enlargement step, a transamidation reaction with a medium ring sized lactam bearing two bulky groups are discussed. These were overcome by altering the reaction sequence and the transamidation reaction was successfully carried out by at first deprotection of the Boc function. spermidine alkaloids; (±)-tetrahydromyricoidine; ring enlargement.
- Song, Jiangao,Hesse, Manfred
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p. 6797 - 6804
(2007/10/02)
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- SYNTHESIS AND PHASE-TRANSFER MEDIATED ALKYLATIONS OF 2-DIETHYLAMINO-4-PHENYLSULFONYL-2-BUTENENITRILE AN EFFICIENT HOMOENOLATE EQUIVALENT
-
The title compound is readily prepared from N-diethylacrylamide in three steps.Alkylation of 1 under phase-transfer conditions yields α-cyanoenamines 4 which can be transformed into saturated or unsaturated (α,β or β,γ) esters.
- Lombaert, Stephane De,Ghosez, Leon
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p. 3475 - 3478
(2007/10/02)
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- DIRECT SYNTHESIS OF Z-UNSATURATED ESTERS. A USEFUL MODIFICATION OF THE HORNER-EMMONS OLEFINATION.
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New phosphonoester reagents and reaction conditions are described which yield Z-alpha,beta-unsaturated esters stereoselectively and in high yield from aliphatic and aromatic aldehydes.
- Still, W. Clark,Gennari, Cesare
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p. 4405 - 4408
(2007/10/02)
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