- Systematic study of the fluorescent properties of cinnamaldehyde phenylhydrazone and its interactions with metals: Synthesis and photophysical evaluation
-
Hydrazones are organic compounds with applications in various fields of research, including fluorescent applications. In this investigation, the compound cinnamaldehyde phenylhydrazone was synthesized by condensation between cinnamaldehyde (1) and phenylh
- Aguilar, Luis F.,Bravo, Manuel A.,Díaz, Katy,González, César,Mellado, Marco,Sariego-Kluge, Rafaela
-
-
Read Online
- Mn(III)-mediated phosphinoylation of aldehyde hydrazones: Direct “one-pot” synthesis of α-iminophosphine oxides from aldehydes
-
A “one-pot” strategy for the straightforward Mn(III)-mediated phosphinoylation of aldehyde hydrazones with diphenylphosphine oxide to furnish α-iminophosphine oxides is described. This mild and practical method allows the direct use of aldehydes as substrates in one pot to generate the hydrazones, which are then engaged “in situ” by the phosphorus reagent in the presence of Mn(OAc)3 oxidant. Thus, the requisite isolation of the hydrazones is not needed in this operation. Conducted mechanistic experiments implicate a pathway involving phosphorus-centered radicals.
- Bian, Xue-Wei,Zhang, Ling,Shoberu, Adedamola,Zou, Jian-Ping
-
supporting information
(2021/04/02)
-
- Facile One-Pot Transformation of Primary Alcohols into 3-Aryl- and 3-Alkyl-isoxazoles and -pyrazoles
-
Various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylisoxazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, NH 2 OH, and then NCS, followed by reaction with alkynes in the presence of Et 3 N. Similarly, various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylpyrazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, PhNHNH 2, and then NCS and decyl methyl sulfide, followed by reaction with alkynes in the presence of Et 3 N. Thus, both 3-aryl- and 3-alkylisoxazoles, and 3-aryl- and 3-alkylpyrazoles could be prepared from readily available primary alcohols in one pot under transition-metal-free conditions.
- Kobayashi, Eiji,Togo, Hideo
-
p. 3723 - 3735
(2019/09/30)
-
- Stereospecific copper(II)-catalyzed tandem ring opening/oxidative alkylation of donor-acceptor cyclopropanes with hydrazones: Synthesis of tetrahydropyridazines
-
Aerobic copper(II)-catalyzed tandem ring opening and oxidative C-H alkylation of donor-acceptor cyclopropanes with bisaryl hydrazones is accomplished to produce tetrahydropyridazines, in which copper(II) plays dual role as a Lewis acid as well as redox catalyst. The reaction is stereospecific, and optically active cyclopropanes can be reacted with high optical purities (89-98% enantiomeric excess). The substrate scope, functional group tolerance, dual role of the copper(II) catalyst, and the use of air as an oxidant are the important practical features. A product bearing a 3-bromoaryl group can be subjected to Pd-catalyzed Suzuki coupling with boronic acid in high yield.
- Mishra, Manmath,De, Pinaki Bhusan,Pradhan, Sourav,Punniyamurthy, Tharmalingam
-
p. 10901 - 10910
(2019/09/13)
-
- The use of enaminones and enamines as effective synthons for MSA-catalyzed regioselective synthesis of 1,3,4-tri- And 1,3,4,5-tetrasubstituted pyrazoles
-
In the present work, an efficient regioselective synthesis of 1,3,4-tri- and 1,3,4,5-tetrasubstituted pyrazoles via a methanesulfonic acid (MSA)-catalyzed reaction of hydrazones with enaminones or enamines is reported. Mechanistically, the formation of the title compounds involves the [2+3] cycloaddition of hydrazones with enaminones or enamines followed by aromatization with acid and oxygen. This convenient method under mild conditions with various hydrazones, enaminones, and enamines was well-tolerated to afford products in good to excellent yields. Compared with the literature methods, this strategy has advantages such as materials that are available economically, metal-free catalysis, excellent regioselectivity, and high efficiency.
- Duan, Liancheng,Zhou, Hui,Gu, Yucheng,Gong, Ping,Qin, Mingze
-
supporting information
p. 16131 - 16137
(2019/11/03)
-
- Aluminium chloride-catalyzed synthesis of 4-benzyl cinnolines from aryl hydrazones
-
An efficient synthesis of 4-benzyl cinnolines from aryl phenylallylidene hydrazone is described. In this report aluminium chloride as a Lewis acid catalyst and toluene as a solvent are used for the synthesis. This method is expected to more advantageous t
- Gogoi, Prasanta,Gogoi, Sandhya Rani,Devi, Namita,Barman, Pranjit
-
p. 1142 - 1148
(2014/04/03)
-
- Oxidized single-walled carbon nanotubes (swcns-cooh) as a new catalyst for the protection of carbonyl groups as hydrazones
-
Nano-materials are considered as suitable heterogeneous catalysts for many organic reactions. Herein oxidized carbon nanotube (SWCNTs-COOH) has been reported as a heterogeneous catalyst, for protection of carbonyl groups as hydrazones in EtOH at 80 C. The reactions proceed smoothly with good to excellent yields, and the SWCNTs-COOH used can be recycled.
- Borazjani, Maryam Kiani,Safaei, Hamid Reza,Panahandeh, Majid,Kiani, Ali Reza,Kiani, Masoumeh,Mofarahi, Masoud
-
p. 279 - 281
(2013/12/04)
-
- Fast hydrazone reactants: Electronic and acid/base effects strongly influence rate at biological pH
-
Kinetics studies with structurally varied aldehydes and ketones in aqueous buffer at pH 7.4 reveal that carbonyl compounds with neighboring acid/base groups form hydrazones at accelerated rates. Similarly, tests of a hydrazine with a neighboring carboxylic acid group show that it also reacts at an accelerated rate. Rate constants for the fastest carbonyl/hydrazine combinations are 2-20 M-1 s-1, which is faster than recent strain-promoted cycloaddition reactions.
- Kool, Eric T.,Park, Do-Hyoung,Crisalli, Pete
-
supporting information
p. 17663 - 17666
(2014/01/06)
-
- Synthesis of substituted 1 H-indazoles from arynes and hydrazones
-
The 1H-indazole skeleton can be constructed by a [3 + 2] annulation approach from arynes and hydrazones. Under different reaction conditions, both N-tosylhydrazones and N-aryl/alkylhydrazones can be used to afford a variety of indazoles. The former reaction affords 3-substituted indazoles either via in situ generated diazo compounds or through an annulation/elimination process. The latter reaction leads to 1,3-disubstituted indazoles likely through an annulation/oxidation process. The reactions operate under mild conditions and can accommodate aryl, vinyl, and less satisfactorily, alkyl groups.
- Li, Pan,Wu, Chunrui,Zhao, Jingjing,Rogness, Donald C.,Shi, Feng
-
experimental part
p. 3149 - 3158
(2012/07/14)
-
- 1,3-dipolar cycloaddition of hydrazones with α-oxo-ketenes: A three-component stereoselective entry to pyrazolidinones and an original class of spirooxindoles
-
Stereodefined monocyclic, spirobicyclic, and bis-spirotricyclic pyrazolidin-3-ones can be prepared efficiently by a three-component reaction involving a 1,3-dipolar cycloaddition of azomethine imines obtained from hydrazones with α-oxo-ketene dipolarophiles generated in situ. The reaction allows the creation of four covalent bonds and two contiguous chiral quaternary centers with excellent diastereoselectivity in a single catalyst/additive-free, highly atom-economical transformation. From a fundamental point of view, the reaction introduces α-oxo-ketenes as effective dipolarophiles in 1,3-dipolar cycloadditions.
- Presset, Marc,Mohanan, Kishor,Hamann, Marie,Coquerel, Yoann,Rodriguez, Jean
-
supporting information; experimental part
p. 4124 - 4127
(2011/10/04)
-
- Dowex polymer-mediated protection of carbonyl groups
-
Dowex (strongly acidic cationic exchange resin) polymer is employed as solid acid catalyst for the clean and less hazardous protection of carbonyl compounds as phenylhydrazones and 2,4-dintrophenylhydrazones in ethanol under reflux conditions. The reactions proceed very smoothly and the yields of the derivatives are excellent. Copyright Taylor & Francis, Inc.
- Niknam, Khodabakhsh,Kiasat, Ali Reza,Karimi, Sadegh
-
p. 2231 - 2236
(2007/10/03)
-
- 1-PHENYLAZO-1-ALKENES
-
Aliphatic aldehyde phenylhydrazones 1 were converted into 1-phenylazo-1-alkenes 3 either by the reaction with I2 and pyridine followed by base induced 1,4-elimination of pyridine.HI (Method A), or via N-(4-methylbenzenesulfonyl)-N-phenylhydrazones 7 which undergo 1,4-elimination of p-toluenesulfinic acid upon treatment with KOt-Bu (Method B).Both procedures yield mixtures of configurational isomers of the phenylazo-alkenes EE- and EZ- 3b-3e; Method B is giving rise to the kinetically controlled isomer mixture (EZ-3 predominant), which equilibrates to the thremodynamicratio (EE-3 predominant) as afforded by Method A.
- Schantl, Joachim G.,Hebeisen, Paul
-
p. 395 - 406
(2007/10/02)
-
- Preparation and Absorption Spectra of Arylhydrazones from α,β-Unsaturated Carbonyl Compounds
-
Substituted arylhydrazones 2-17, 19, and 23-29 were prepared from several α,β-unsaturated carbonyl compounds and their absorption spectra examined.The dependence on concentration of certain near-infrared bands of the spectra has been associated with aggregation and appears to correlate with structural elements of the compounds in a way suggesting significant intermolecular effects, either hydrogen bonding or charge transfer of both.
- Hearn, Michael J.,Lebold, Suzanne A.,Sinha, Anvita,Sy, Karen
-
p. 4188 - 4193
(2007/10/02)
-
- Synthesis of New Polycyclic Carbazoloquinones
-
Some new policyclic carbazoloquinones, substituted 6H-pyridocarbazoles (V) have been synthesized by the interaction of the Diels-Alder adducts (II), obtained from the addition of cinnamyliden-anils (I) to 4,4-dimethoxyquinone in 1:1 molar ratio, wi
- Hammam, A. S.,Youssef, M. S. K.,Abbady, M. A.,Ibrahim, R. R.
-
p. 565 - 570
(2007/10/02)
-