Showing papers on "Hydrazone published in 1994"
TL;DR: In this paper, the synthesis of two new 1, 1,1′-bis(phospholano)ferrocene ligands with enantioselectivities as high as 83% ee was described.
83 citations
TL;DR: Copper(II) complexes of the type Cu[Tl(SCN2]2·L [where L = benzoic hydrazide (BH), isonic-infinitive hydrazides (INH), salicyclic hdyrazide(SH), anthranilic hydride (AH), p-hydroxybenzoic hexagonal hexagonal polygonal hexagon (PHBH) and their isopropanone derivatives were synthesized and characterized.
61 citations
TL;DR: Diethynylmethanobuckminsterfullerene has been prepared by reaction of the lithium salt of 1,5-bis(trimethylsilyl)-1,4-pentadiyn-3-one (p-toluenesulfonyl) hydrazone with C{sub 60} followed by desilylation as discussed by the authors.
Abstract: Diethynylmethanobuckminsterfullerene has been prepared by reaction of the lithium salt of 1,5-bis(trimethylsilyl)-1,4-pentadiyn-3-one (p-toluenesulfonyl) hydrazone with C{sub 60} followed by desilylation The derivative was structurally characterized by NMR, IR, UV-vis, and CI-TQMS spectroscopies
56 citations
TL;DR: Chiral 1-azadienes 1 derived from alpha,beta-unsaturated aldehydes and Enders' hydrazines cycloadd to cyclic dienophiles with high facial selectivities can be readily converted into enantiomerically pure piperidine derivatives as discussed by the authors.
Abstract: Chiral 1-azadienes 1 derived from alpha,beta-unsaturated aldehydes and Enders' hydrazines cycloadd to cyclic dienophiles with high facial selectivities. The adducts can be readily converted into enantiomerically pure piperidine derivatives.
47 citations
TL;DR: In this article, 2-chloroformylhydrazones of aromatic aldehydes or ketones with various hydrazines were converted to monocarbonohydrazone derivatives and/or tetrahydro-1,2,4,5-tetrazin-3(2H)-one derivatives.
37 citations
TL;DR: In this paper, the intermolecular coupling of a variety of ketones with some types of O-methyl oximes took place when a mixture of both components was electrochemically reduced in i-PrOH with an Sn cathode.
Abstract: The intermolecular coupling of a variety of ketones with some types of O-methyl oximes took place when a mixture of both components was electrochemically reduced in i-PrOH with an Sn cathode. The product, β-methoxyamino alcohol was easily converted to β-amino alcohol by simple reduction. A chiral ligand effective for the enantioselective addition of diethylzinc to an aldehyde was easily obtained from the product formed by the electroreductive coupling of (-)-menthone with O-methylacetaldoxime. The intermolecular coupling of a ketone with a N,N-dimethylhydrazone or nitrone was also promoted by the electroreduction. Furthermore, the electroreductive coupling of a carbonyl group with an intramolecular O-methyl oxime moiety gave the corresponding cyclized product stereoselectivity
36 citations
34 citations
TL;DR: In this paper, a one-pot synthesis of 3-(fluoroalky 1)pyrazoles from polyfluoroalkyl iodides has been developed, which involves the formation of a hydrazone intermediate, followed by elimination of hydrogen halide and intramolecular nucleophilic addition.
Abstract: 3-(Fluoroalkyl)pyrazoles 3 have been synthesized in excellent yields by reaction of various fluoroalkyl aldehydes with NH2NH2·HOAc under mild conditions. It appears that the reaction involves the formation of a hydrazone intermediate, followed by elimination of hydrogen halide and intramolecular nucleophilic addition. A practical one-pot synthesis of 3-(fluoroalky1)pyrazoles from polyfluoroalkyl iodides 1 has also been developed.
31 citations
TL;DR: In this paper, a practical and efficient enantioselective synthesis of 2-sulfenylated aldehydes (S)-6 is described, based on α-alkylation of SAMP hydrazones.
27 citations
TL;DR: In this paper, the equilibria of condensation reactions of hydrazine and phenylhydrazine with p-(dimethylamino)benzaldehyde in micellar sodium dodecyl sulfate solutions were studied spectrophotometrically.
Abstract: Kinetics and equilibria of condensation reactions of hydrazine and phenylhydrazine with p-(dimethylamino)benzaldehyde in micellar sodium dodecyl sulfate solutions were studied spectrophotometrically. The reaction with hydrazine involves consecutive reversible addition of two aldehyde molecules. The reaction rate under conditions of high excess of aldehyde is determined by the acid-catalyzed attack of aldehyde by hydrazinium cation. The reaction with phenylhydrazine proceeds slower and is characterized by a much smaller equilibrium constant as compared to the reaction with hydrazine
26 citations
TL;DR: In this article, an efficient Cu(acac)2-catalyzed oxidation of ketohydrazones afforded the corresponding α-diazoketones or ketazines in high yields depending on the reaction conditions.
TL;DR: The electronic properties of 2,4,5-trihydroxyphenylalanine quinone (TPQ), the cofactor of bovine serum amine oxidase, and some adducts with hydrazines were investigated by means of low-molecular-weight models and semiempirical molecular orbital calculation methods, confirming that copper is not within bonding distance of the oxidized cofactor.
Abstract: The electronic properties of 2,4,5-trihydroxyphenylalanine quinone (TPQ), the cofactor of bovine serum amine oxidase [Janes, S. M., Mu, D., Wemmer, D., Smith, A. J., Kaur, S., Maltby, D., Burlingame, A. L., & Klinman, J. P. (1990) Science 248, 981-987], and some adducts with hydrazines were investigated by means of low-molecular-weight models and semiempirical molecular orbital calculation methods. The enzyme visible band was assigned to the first pi-->pi* transition of the cofactor in p-quinonic form, with the C-4 hydroxyl ionized and hydrogen bonded either to a water molecule or to a basic protein residue. The spectra of the protein adducts with some substituted hydrazines were well accounted for by assuming the inhibitor bound to the C-5 carbonyl, usually in azo form. The adduct with the unsubstituted hydrazine was instead assigned an o-quinone hydrazone form, stabilized by an internal hydrogen bond between the amino group and the ortho carbonyl oxygen, a larger electron delocalization, and formation of a hydrogen bond at the C-6 ionized hydroxyl. On the basis of these assignments, the reaction of the protein with benzylhydrazine [Morpurgo, L., Agostinelli, E., Muccigrosso, J., Martini, F., Mondovi, B., & Avigliano, L. (1989) Biochem. J. 260, 19-25] was rewritten. All examined electronic transitions, though highly sensitive to cofactor ionization and hydrogen bonding, could be accounted for without introducing perturbations due to copper. This confirms that copper is not within bonding distance of the oxidized cofactor.
TL;DR: In this paper, 1,3-Dibenzoyl-2,4-diacyl- and 1,5-diminear diacylbenzene were prepared in good yields via a further application of a recently reported two step replacement of phenolic hydroxyl by an acyl group.
TL;DR: In this paper, the structure of four imino aza dipeptides, analogues of the Pro-Gly, Pro-Ala, and Pro-Phe, has been studied in solution by 1 H-NMR and IR spectroscopy, and in the solid state by X-ray diffraction.
TL;DR: Chiral β-nitrohydrazones 7 can be easily prepared in good yields and diastereoselectivities by non catalyzed Michael addition of formaldehyde SAMP hydrazone 6 to simple nitroolefins.
TL;DR: The first example of asymmetric radical cyclization of a SAMP β-allenic hydrazone was described in this article, where the allenic and hydrazones were substituted with allenic moieties.
TL;DR: Three benzil based macrocyclic oxygen-, nitrogen-, and sulfur-containing ligands, (3,4,10,11-tetraphenyl-1,2,5,6,8,9,12,13-octaazacyclotetradeca-7,14-dithione-2,4.9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 27, 28, 30, 31, 34, 35, 34
Abstract: Three benzil based, macrocyclic oxygen-, nitrogen-, and sulfur-containing ligands, (3,4,10,11-tetraphenyl-1,2,5,6,8,9,12,13-octaazacyclotetradeca-7,14-dithione-2,4,9,11-tetraene) ethanol (L 1 ), 10,11-diethoxy-3,4,10,11-tetraphenyl-1,2,5,6,8,9,12,13-octaazacyclotetradeca-7,14-dithione-2,4-diene (L 2 ), (3,4,10,11-tetraphenyl-1,2,5,6,8,9,12,13-octaazacyclotetradeca7,14-dione-2,4,9,11-tetraene) ethanol (L 3 ); a cyclic ligand, 6-ethoxy-1,6-diphenyl-4-oxo-3,4,5,6-tetrahydro-2,3,5-triazine (L 5 ) and two open chain ligands, benzilsemicarbazone (L 5 ) and benzilbisthiosemicarbazone (L 4 ) are reported
TL;DR: In this article, a macroporous cross-linked acrolein-styrene copolymer was synthesized and the aldehyde groups were converted to hydrazone (P-HZ) or phenylhydrazone(P-PHZ) derivatives.
TL;DR: N-dimethylaluminum-N',N'-dimethylhydrazide, synthesized from N,Ndimethyl hydrazine and trimethyl aluminum, reacts with aromatic ketones or with electronically unfavourable substrates to give the corresponding hydrazones in high yield as discussed by the authors.
Abstract: N-dimethylaluminum-N',N'-dimethylhydrazide, synthesized from N,N-dimethylhydrazine and trimethylaluminum, reacts with aromatic ketones or with electronically unfavourable substrates to give the corresponding hydrazones in high yield. Subsequent exchange with anhydrous hydrazine affords the N-unsubstituted hydrazones
TL;DR: In this paper, the synthesis of substituted furo[2,3-f]quinoline-4,5-diones was performed using 2-ethoxybut-2-enal N,N-dimethylhydrazone as a nucl
Patent•
28 Jun 1994
TL;DR: In this paper, the authors defined compounds of formula (I), or salts thereof0, in which G is a group of the formula G?1, G2 or G3; R 1? is H or alkyl; R 2 is COOH, CSOH or a carboxylic- or thiocarboxyly-group derivative with 1 to 20 C-atoms or an acyl group of a CO-Ro type with 1-to 12 C-atom or an imino, hydrazone or oxime derivative of the CO
Abstract: The invention concerns compounds of formula (I), or salts thereof0, in which G is a group of the formula G?1, G2 or G3; R1? is H or alkyl; R2 is COOH, CSOH or a carboxylic- or thiocarboxylic-group derivative with 1 to 20 C-atoms or an acyl group of the CO-Ro type with 1 to 12 C-atoms or an imino, hydrazone or oxime derivative of the CO-Ro group, and R?o, R3a, R4a, R3b, R4b?, W, X, Y and Z are as defined in claim 1. Such compounds are suitable for use as selective herbicides and plant-growth regulators in agricultural crop plants. They can be prepared by prior art methods via intermediates, some of which are novel, from the group comprising the benzenesulphonamides (II), benzenesulphonyliocyanates (IV), benzenesulphochlorides (VI) and heterocyclically substituted carbamates (III), amines (V) or [thio]isocyanates (XIX).
TL;DR: In this article, the equilibrium between (E)-and (Z)-isomers of acylhydrazones of 1,3-dioxocompounds was shown to convert into 1-acyl-5-acy loxy-2-pyrazolines.
TL;DR: In this article, arylhydrazones were obtained by standard reactions; the Grignard reac- tion of 2-cyano-and 4-cyanopyrimidine (1a,b), (4a-c) gave 2-pyrimidyl- and 4-pyridyl ketones (2a,e), (5a,c), which reacted with aryhlhydrazi-nes to yield the desired ketone arylshydrazone (3a-e),(6a-C)
Journal Article•
TL;DR: In this article, indole-3-acetic acids were synthesized through indole 3-glyoxylic acids, followed by hydrazone formation with p-toluenesulfonhydrazide, then reduction of the hydrazones with sodium borohydride.
TL;DR: The 3-(arylhydrazono)methyl-2-oxo-1,2-dihydroquinoxalines (9-11) were synthesized by the reaction of quinoxaline with various p-substituted benzenediazonium salts.
TL;DR: In this article, a novel reaction of 11,11,12,12-tetracyanoanthraquinodimethane was reported, its transformation into 10-dicyanomethylene-anthrone hydrazone by reaction with hydrazine.
Abstract: A novel reaction of 11,11,12,12-tetracyanoanthraquinodimethane — its transformation into 10-dicyanomethylene-anthrone hydrazone by reaction with hydrazine — is reported. This hydrazone seems to be a convenient starting material in the synthesis of anthracene derivatives and compounds incorporating anthracenic fragments, but is itself as a conjugated donor acceptor system a material with interesting physical properties.
01 Jan 1994
TL;DR: The optically active fluorescent tagging reagents, 4-(2-carbazoylpyrrolidin-1-yl)-7-nitro-2,1,3-benzoxadiazole [R(+)-and S(−)-NBD-ProCZ] and 4(2-CARBASRIDIN-1]-7-(N,N-dimethylaminosulfonyl)-2, 1,3,3-, NBD-proCZ], react with enantiomers of aldehydes and ket
Abstract: The optically active fluorescent tagging reagents, 4-(2-carbazoylpyrrolidin-1-yl)-7-nitro-2,1,3-benzoxadiazole [R(+)-and S(–)-NBD-ProCZ] and 4-(2-carbazoylpyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole [R(+)-and S(–)-DBD-ProCZ], react with enantiomers of aldehydes and ketones under mild conditions (65 °C for 10 min) in the presence of trichloroacetic acid (TCA). Fluorescent hydrazone diastereomers derived from some chiral ketones were separated by reversed-phase and/or normal-phase high-performance liquid chromatography, on achiral columns.
TL;DR: The addition of organometallic reagents to imines or hydrazones containing 1,3-oxathiane as a chiral auxiliary with high diastereoselectivity has been used as a key reaction for the preparation of chiral β-amino alcohols as discussed by the authors.
Abstract: The addition of organometallic reagents to imines or hydrazones containing 1,3-oxathiane as a chiral auxiliary proceeded with high diastereoselectivity and can be used as a key reaction for the preparation of chiral β-amino alcohols.