98324-47-1Relevant articles and documents
Palladium-Catalyzed Three-Component coupling reactions: 1,1 -Difunctionalization of activated alkenes
Rodriguez, Arantxa,Moran, Wesley J.
supporting information; experimental part, p. 1313 - 1316 (2009/07/26)
A three-component coupling reaction was developed to access 3,3-oxyarylpropionate derivatives. Each of the three reaction components can be varied, allowing the modular synthesis of a range of important chiral building blocks. Wiley-VCH Verlag GmbH & Co, KGaA.
AZIRIDINE ALDEHYDES, AZIRIDINE-CONJUGATED AMMO DERIVATIVES, AZIRIDINE-CONJUGATED BIOMOLECULES AND PROCESSES FOR THEIR PREPARATION
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Page/Page column 76, (2008/12/05)
The present invention relates to unprotected amino aldehydes and applications for same. More particularly, the present invention relates to novel aziridine aldehydes and processes for preparing these novel compounds. The invention also relates to aziridine-conjugated amino derivatives, and processes for preparing the same. Pentacyclic compounds may be prepared using the aziridine aldehydes of the present invention, and the invention relates to these compounds and the processes by which they are made. The invention also relates to aziridine-conjugated bioactive molecules, such as amino acids and peptides, and processes for preparing such compounds.
Azavinyl azomethine ylides from thermal ring opening of α-aziridinohydrazones: Unprecedented 1,5-electrocyclization to imidazoles
Attanasi, Orazio A.,Davoli, Paolo,Favi, Gianfranco,Filippone, Paolino,Forni, Arrigo,Moscatelli, Giada,Prati, Fabio
, p. 3461 - 3464 (2008/02/12)
Michael-type addition of aziridinecarboxylates to 1,2-diaza-1,3-butadienes under solvent-free conditions (SFC) resulted in the formation of α-aziridinohydrazone adducts. In toluene under reflux, α-aziridinohydrazones gave imidazoles in moderate to good yi
Readily available unprotected amino aldehydes
Hili, Ryan,Yudin, Andrei K.
, p. 14772 - 14773 (2008/02/05)
We report a new class of bench-stable compounds that contain seemingly incompatible functional groups: an aldehyde and an unprotected secondary amine. The thermodynamic driving force to undergo condensation between these two functionalities is offset by a
Generation and reactivity of ketyl radicals with lignin related structures. On the importance of the ketyl pathway in the photoyellowing of lignin containing pulps and papers
Fabbri, Claudia,Bietti, Massimo,Lanzalunga, Osvaldo
, p. 2720 - 2728 (2007/10/03)
(Chemical Equation Presented) Ketyl radicals with lignin related structures have been generated by means of radiation chemical and photochemical techniques. In the former studies ketyl radicals are produced by reaction of α-carbonyl-β-aryl ether lignin models with the solvated electron produced by pulse radiolysis of an aqueous solution at pH 6.0. The UV-vis spectra of ketyl radicals are characterized by three main absorption bands. The shape and position of these bands slightly change when the spectra are recorded in alkaline solution (pH 11.0) being now assigned to the ketyl radical anions and a pKa = 9.5 is determined for the 1-(3,4,5-trimethoxyphenyl)-2- phenoxyethanol-1-yl radical. Decay rates of ketyl radicals are found to be dose dependent and, at low doses, lie in the range (1.7-2.7) × 103 s-1. In the presence of oxygen a fast decay of the ketyl radicals is observed (k2 = 1.8-2.7 × 109 M-1 s -1) that is accompanied by the formation of stable products, i.e., the starting ketones. In the photochemical studies ketyl radicals have been produced by charge-transfer (CT) photoactivation of the electron donor-acceptor salts of methyl viologen (MV2+) with α-hydroxy-α- phenoxymethylaryl acetates. This process leads to the instantaneous formation of the reduced acceptor (methyl viologen radical cation, MV+?), as is clearly shown in a laser flash photolysis experiment by the two absorption bands centered at 390 and 605 nm, and an acyloxyl radical [ArC(CO 2?)(OH)CH2(OC6H5)], which undergoes a very fast decarboxylation with formation of the ketyl radicals. Steady-state photoirradiation of the CT ion pairs indicates that 1-aryl-2-phenoxyethanones are formed as primary photoproducts by oxidation of ketyl radicals by MV2+ (under argon) or by molecular oxygen. Small amounts of acetophenones are formed by further photolysis of 1-aryl-2-phenoxyethanones and not by β-fragmentation of the ketyl radicals. The high reactivity of ketyl radicals with oxygen coupled with the low rates of β-fragmentation of the same species have an important bearing in the context of the photoyellowing of lignin containing pulps and papers.
Intermediary compounds for the hemisynthesis of taxanes and preparation processes therefor
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, (2008/06/13)
The present invention relates to new intermediates for the semisynthesis of taxanes and their preparation processes. It relates to derivatives of oxazolidines or oxazolidinones, as well as to new derivatives of baccatine III. The general process for the synthesis of taxanes according to the invention enables to obtain a product such as PACLITAXEL in only five steps from products available in the market, compared to nine steps in general, for processes of the prior art.
Method of producing L-phenylalanine
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, (2008/06/13)
There is provided a method of producing L-phenylalanine in high optical purity which comprises treating an N-acylphenylalanine alkyl ester in L form, in the presence of water, with an enzyme capable of hydrolyzing the N-acylphenylalanine alkyl ester in L form to give L-phenylalanine.
SYNTHESIS, CHIROPTICAL PROPERTIES AND ABSOLUTE CONFIGURATION OF α-PHENYLGLYCIDIC ACID
Whitman, Christian P.,Craig, J. Cymerman,Kenyon, George L.
, p. 1183 - 1192 (2007/10/02)
The (+)- and (-) enantiomers of potassium α-phenylglycidate, an irreversible inhibitor of the enzyme mandelate racemase, were synthesized by resolution of the diastereomeric esters with R-(-)-2-octanol.Base-catalyzed ring-opening of the resolved α-phenylglycidate esters gave the enantiomers of 2,3-dihydroxy-2-phenylpropaonic acid, also obtained by resolution of the racemic dihydroxy acid using ephedrine.A comparison of the chiroptical properties of the esters of α-phenylglycidic and 2,3-dihydroxy-2-phenylpropionic acids with those of the structurally similar atrolactic and mandelic acids and their 2-methoxy-derivatives showed that the (-)-methyl 2,3-dihydroxy-2-phenylpropanoate corresponding to the (+)-enantiomer of potassium α-phenylglycidate, as well as the esters of α-phenylglycidic acid derived from the same (+)-potassium salt, were all configurationally related to S-(+)-atrolactic and mandelic acids.The configurational assignments made on the basis of the chiroptical data were confirmed by lithium aluminium hydride reduction of the (-)-2-octyl S- and R-α-phenylglycidates, which led exclusively to the R-(-)- and S-(+)-2-phenyl-1,2-propanediols, respectively, previously related configurationally to R-(-)- and S-(+)-atrolactic acids.
SYNTHESIS OF α,β-EPOXY DIAZOMETHYL KETONES
Thijs, L.,Smeets, F. L. M.,Cillissen, P. J. M.,Harmsen, J.,Zwanenburg, B.
, p. 2141 - 2144 (2007/10/02)
The preparation of eighteen epoxy diazomethyl ketones 1 is described.Two general methods were developed.Firstly, treatment of the mixed anhydrides of glycidic acids and carbonic acid ester with diazomethane led to the title compounds in yields ranging from 17-74 percent.Secondly, glycidyl chlorides which were obtained from sodium glycidates and oxalyl chloride, gave the desired products upon treatment with diazomethane ( yields 60-74 percent).The required α,β-epoxy carboxylic esters were prepared by Darzens condensation and epoxidation of α,β-unsaturated esters, but in some cases also by reaction of α-oxo carboxylic esters with diazomethane.
