- A mild method for conversion of epoxides into α-chloro ketones
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Epoxides on treatment with DMSO, oxalyl chloride, and 10 mole % of methanol in the presence of triethylamine at -60°C are converted to α-chloro ketones in high yield.
- Raina,Bhuniya,Singh
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- Photoenzymatic Synthesis of α-Tertiary Amines by Engineered Flavin-Dependent "ene"-Reductases
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α-Tertiary amines are a common motif in pharmaceutically important molecules but are challenging to prepare using asymmetric catalysis. Here, we demonstrate engineered flavin-dependent ‘ene'-reductases (EREDs) can catalyze radical additions into oximes to prepare this motif. Two different EREDs were evolved into competent catalysts for this transformation with high levels of stereoselectivity. Mechanistic studies indicate that the oxime contributes to the enzyme templated charge-transfer complex formed between the substrate and cofactor. These products can be further derivatized to prepare a variety of motifs, highlighting the versatility of ERED photoenzymatic catalysis for organic synthesis.
- Gao, Xin,Turek-Herman, Joshua R.,Choi, Young Joo,Cohen, Ryan D.,Hyster, Todd K.
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supporting information
p. 19643 - 19647
(2021/12/01)
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- A mild method for the replacement of a hydroxyl group by halogen. 1. Scope and chemoselectivity
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α-Chloro-, bromo- and iodoenamines, which are readily prepared from the corresponding isobutyramides have been found to be excellent reagents for the transformation of a wide variety of alcohols or carboxylic acids into the corresponding halides. Yields are high and conditions are very mild thus allowing for the presence of sensitive functional groups. The reagents can be easily tuned allowing therefore the selective monohalogenation of polyhydroxylated molecules. The scope and chemoselectivity of the reactions have been studied and reaction mechanisms have been proposed.
- Munyemana, Fran?ois,George, Isabelle,Devos, Alain,Colens, Alain,Badarau, Eduard,Frisque-Hesbain, Anne-Marie,Loudet, Aurore,Differding, Edmond,Damien, Jean-Marie,Rémion, Jeanine,Van Uytbergen, Jacqueline,Ghosez, Léon
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p. 420 - 430
(2015/12/31)
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- 3-Cyano-5-thiazaheteroaryl-dihydropyridine and the use thereof for the treatment of cardiovascular diseases
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The present application relates to novel aryl-substituted 3-cyano-5-thiazolyl- and 3-cyano-5-thiadiazolyl-1,4-dihydropyridines, a process for their preparation, their use for the treatment and/or prophylaxis of diseases, and their use for the manufacture of medicaments for the treatment and/or prophylaxis of diseases, especially cardiovascular disorders.
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Page/Page column 16
(2010/10/03)
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- Method for preparing chiral diphosphines
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The invention concerns a method for preparing a compound of formula (1) wherein: A represents naphthyl or phenyl optionally substituted; and Ar1, Ar2independently represent a saturated or aromatic carbocyclic group, optionally substituted.
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- A general synthesis of enantiopure 1,2-aminoalcohols via chiral morpholinones
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Eleven optically active 1,2-aminoalcohols 20a-i and 26b-c were prepared from D-phenylglycine via cyclic imines 7b-i (or enamine 7a). The key step of the strategy is the diastereoselective reduction of chiral oxazinones 7a-i.
- Segat-Dioury, Fabienne,Lingibé, Olivier,Graffe, Bernadette,Sacquet, Marie-Claude,Lhommet, Gérard
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p. 233 - 248
(2007/10/03)
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- Preparation of 1-aminoalkylphosphonic acids and 2-aminoalkylphosphonic acids by reductive amination of oxoalkylphosphonates
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By reacting dialkyl 1-oxo- or 2-oxoalkylphosphonates with benzhydrylamine followed by reduction with triacetoxyborohydride and acid hydrolysis gave corresponding aminoalkylphosphonic acids with satisfactory yields. The use of benzylamine, α-methylbenzylamine and tritylamine was unsuccessful in the case of dialkyl 1-oxoalkylphosphonates whereas conversion of 2-oxoalkylphosphonates was also achieved although with lower yields.
- Ryglowski, Artur,Kafarski, Pawel
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p. 10685 - 10692
(2007/10/03)
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- A Systematic Study on the Bakers'Yeast Reduction of 2-Oxoalkyl Benzoates and 1-Chloro-2-alkanones
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The bakers' yeast reduction of a series of 2-oxoalkyl arenecarboxylates (1a-f) (R=CH3 to n-C6H13; X=H) and the phenyl-modified derivatives (1g-l) (R=n-C5H11, X=OH, CH3, F, Cl, Br, or I) as well as 1-chloro-2-alkanones R(C=O)CH2Cl (6a-f) (R=CH3 to n-C6H13) were systematically investigated.The substrate specificities, configuration and percentee of the reduction products were found to be highly dependent on the length of the alkyl group (R) and the α substituent.Thus, the benzoates 1a-f gave optically active 2-hydroxyalkyl benzoates (2a-f) (R, configuration, percentee) (a: CH3, S, 99; b: C2H5, S, 98; c: C3H7, S, 26; d: n-C4H9, R, 55; e: n-C5H11, S, 15; f: n-C6H13, S, 63) in 11-91percent yields.Among the modification experiments of the phenyl group, 1g-l, the p-iodo substituent markedly increased the ee from 15 to 71percent, although the yield was rather lowered (22percent yield).The reduction of α-chloro ketones 6a-f also gave optically active 1-chloro-2-alkanols (7a-f) in 16-69percent yields.
- Sakai, Takashi,Wada, Kou,Murakami, Takahiko,Kohra, Kiichiro,Imajo, Norihisa,et al.
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p. 631 - 638
(2007/10/02)
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- SYNTHESE ET ETUDE ELECTROCHIMIQUE DE POLY(ALKYL-3 SELENOPHENES)
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Synthesis of 3-alkyl selenophenes via chloromethyl ketones and acetylenic chlorhydrins is described.The electropolymerisation yields electroactive and soluble polymers with high conductivity in the doped state.
- Mahatsekake, C.,Catel, J. M.,Andrieu, C. G.,Ebel, M.,Mollier, Y.,Tourillon, G.
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- Free Radical Substitution. Part 38. The Effect of Solvent on the Atomic Chlorination and Bromination of 2-Substituted Butanes and the Importance of Steric Effects
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The relative selectivity of atomic halogenation of 2-substituted butanes is influenced by the phase and by solvents.There are solvents which increase the selectivity compared with the gas phase and solvents which decrease the relative selectivity.However the most striking feature of the halogenation (especially the bromination) of 2-substituted butanes is the high reactivity of the 2-position notwithstanding very unfavourable polar effects.This reactivity is attributed to the release of steric compression associated with the abstraction of the tertiary hydrogen atom.The halogenation of butan-2-ol esters is associated with some decomposition of 2-butyl radical (OCOR)CH3> and the chlorination of 2-phenylbutane with the formation of olefins 2-phenylbut -1-ene and 2-phenylbut-2-ene.
- Atto, Saeed Y.,Tedder, John M.,Walton, John C.
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p. 629 - 634
(2007/10/02)
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- Chlorination of Aliphatic Ketones in Methanol
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The chlorination of aliphatic ketones in methanol has been examined.The product distributions in methanol differ substantially from those obtained by chlorination in carbon tetrachloride.The reaction in methanol favors addition of chlorine to the least substituted carbon α to the carbonyl group.The effect is especially pronounced if an α carbon bearing two substituents is present.The distribution of products is determined by the relative stability of the enol ethers formed from the ketone under the reaction conditions.
- Gallucci, R. R.,Going, R.
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p. 2532 - 2538
(2007/10/02)
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- Thiazoline derivatives
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New thiazoline derivaties of the formula: STR1 wherein R1 represents hydrogen, an alkyl radical of 1 or 2 carbon atoms or methoxymethyl, R2 represents an alkyl radical of 1 or 2 carbon atoms in the 4-, 5- or 6-position, and R3 represents methyl, or alternatively R3 represents hydrogen and either R1 represents hydrogen, an alkyl radical of 1 through 4 carbon atoms, or an alkoxymethyl radical in which the alkyl moiety contains 1 through 4 carbon atoms, and R2 represents an alkyl radical of 1 through 4 carbon atoms in the 4-, 5- or 6-position, or R1 represents cyclopropyl and R2 represents hydrogen are useful as medicaments and, more particularly, as anti-ulcer agents.
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- N-(Heterocycl ic-alkyl)-9-xanthenylamines
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The compounds are N-(imidazolylalkyl, imidazolinylalkyl and tetrahydropyrimidylalkyl)-9-xanthenylamines which have gastric acid secretion inhibitory activity.
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