- I2-Promoted [4 + 2] cycloaddition of: In situ generated azoalkenes with enaminones: Facile and efficient synthesis of 1,4-dihydropyridazines and pyridazines
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A facile and efficient strategy for the synthesis of 1,4-dihydropyridazines and pyridazines through I2-promoted [4 + 2] cycloaddition of in situ generated azoalkenes with enaminones has been developed. The switch in selectivity is attributed to the judici
- Baell, Jonathan B.,Feng, Jiajun,He, Tiantong,Huang, Fei,Xie, Yuxing,Yu, Yang
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supporting information
p. 9483 - 9493
(2020/12/15)
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- Multi-substituted pyrrole derivative and preparation method thereof
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The invention discloses a multi-substituted pyrrole derivative and a preparation method thereof, and relates to the field of organic synthesis. According to the preparation method, diazonium or phenylhydrazone reacts with amino substituted unsaturated car
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Paragraph 0029
(2020/02/27)
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- Rh(iii)-catalyzed alkynylation: Synthesis of functionalized quinolines from aminohydrazones
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Rhodium-catalyzed, chemo- and regioselective synthesis of functionalized quinolines using 2-aminohydrazones and terminal alkynes has been described. The reaction is oxidant/base-free and tolerates a wide variety of functional groups and has been successfu
- Kumar, Pradeep,Garg, Vineeta,Kumar, Manoj,Verma, Akhilesh K.
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supporting information
p. 12168 - 12171
(2019/10/22)
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- Pd-Catalyzed Tandem Coupling Reaction of 2-gem-Dibromovinylanilines and N-Tosylhydrazones to Construct 2-(1-phenylvinyl)-indoles
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A novel palladium(0)-catalyzed intermolecular coupling reaction of 2-gem-dibromovinylanilines and N-tosylhydrazones was reported to construct 2-(1-phenylvinyl)-indoles efficiently. The indole bearing 1, 1-disubstituted alkenes were obtained in one step wi
- Song, Jian,Chi, Xiaochen,Meng, Long,Zhao, Pingping,Sun, Fenggang,Zhang, Daopeng,Jiao, Luyang,Liu, Qing,Dong, Yunhui,Liu, Hui
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supporting information
p. 3599 - 3604
(2019/06/27)
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- Diversity-Orientated Stereoselective Synthesis through Pd-Catalyzed Switchable Decarboxylative C?N/C?S Bond Formation in Allylic Surrogates
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Switchable catalytic transformation of reactants can be a powerful approach towards diversity-orientated synthesis from easily available molecular synthons. Herein, an endogenous ligand-controlled, Pd-catalyzed allylic substitution allowing for either selective C?N or C?S bond formation using vinylethylene carbonates (VECs) and N-sulfonylhydrazones as coupling partners has been developed. This versatile methodology provides a facile, divergent route for the highly chemo- and stereoselective synthesis of functional allylic sulfones or sulfonohydrazides. The newly developed protocol features wide substrate scope (nearly 80 examples), broad functional group tolerance, and potential for the late-stage functionalization of bioactive compounds. The isolation and crystallographic analysis of a catalytically competent π-allyl Pd complex suggests that the pathway leading to the allylic products proceeds through a different manifold as previously proposed for the functionalization of VECs with nucleophiles.
- Deng, Lei,Kleij, Arjan W.,Yang, Weibo
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supporting information
p. 19156 - 19161
(2018/11/30)
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- Zinc-promoted cyclization of tosylhydrazones and 2-(dimethylamino)malononitrile: An efficient strategy for the synthesis of substituted 1-tosyl-1: H -pyrazoles
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A Zn(OTf)2-promoted cyclization reaction of tosylhydrazones with 2-(dimethylamino)malononitrile has been successfully developed providing an efficient strategy for the synthesis of substituted 1-tosyl-1H-pyrazoles.
- Zhang, Bang-Hong,Lei, Lin-Sheng,Liu, Si-Zhan,Mou, Xue-Qing,Liu, Wei-Ting,Wang, Shao-Hua,Wang, Jie,Bao, Wen,Zhang, Kun
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supporting information
p. 8545 - 8548
(2017/08/04)
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- Hydrohydrazination of Arylalkynes Catalyzed by an Expanded Ring N-Heterocyclic Carbene (er-NHC) Gold Complex under Solvent-Free Conditions
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[(THD-Dipp)AuOTf], supported by the strongly electron donating, sterically bulky THD-Dipp (1,3-bis(2,6-diisopropylphenyl)hexahydro-2H-1,3-diazepine-2-ylidene) seven-membered N-heterocyclic carbene ligand, efficiently promotes intermolecular addition of Ts- and Boc-hydrazine to arylalkynes under solvent-free conditions.
- Morozov, Oleg S.,Gribanov, Pavel S.,Asachenko, Andrey F.,Dorovatovskii, Pavel V.,Khrustalev, Victor N.,Rybakov, Viktor B.,Nechaev, Mikhail S.
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supporting information
p. 1463 - 1468
(2016/05/19)
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- I2-TBHP-catalyzed oxidative cross-coupling of N -sulfonyl hydrazones and isocyanides to 5-aminopyrazoles
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I2-TBHP-catalyzed oxidative cross coupling of N-sulfonyl hydrazones with isocyanides has been realized for the synthesis of 5-aminopyrazoles through formal [4 + 1] annulation via in situ azoalkene formation. Notable features are the metal/alkyn
- Senadi, Gopal Chandru,Hu, Wan-Ping,Lu, Ting-Yi,Garkhedkar, Amol Milind,Vandavasi, Jaya Kishore,Wang, Jeh-Jeng
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supporting information
p. 1521 - 1524
(2015/03/30)
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- Solvent-free synthesis of hydrazones and their subsequent N-alkylation in a Ball-mill
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A large variety of Boc-, Bz-, Ts-, and Fmoc- protected hydrazones were prepared via condensation of an equimolar amount of carbonyl-compound and the corresponding hydrazine using a ball-mill. Hydrazones were always obtained in a quantitative yield and no solvents were used at any step. In a second step, we realized the first solvent-free N-allylation and N-benzylation of these hydrazones.
- Nun, Pierrick,Martin, Charlotte,Martinez, Jean,Lamaty, Frédéric
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supporting information; experimental part
p. 8187 - 8194
(2011/10/31)
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- Pd-catalyzed oxidative cross-coupling of N-tosylhydrazones with arylboronic acids
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The Pd-catalyzed reaction of N-tosylhydrazones and arylboronic acids provides olefin derivatives. This oxidative cross-coupling is suggested to proceed through a migratory insertion process of a Pd carbene intermediate.
- Zhao, Xia,Jing, Jing,Lu, Kui,Zhang, Yan,Wang, Jianbo
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supporting information; experimental part
p. 1724 - 1726
(2010/07/06)
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- Controlled release of volatile aldehydes and ketones from dynamic mixtures generated by reversible hydrazone formation
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Delivery systems generated by reversible hydrazone formation from hydrazine derivatives (see Fig. 1) and carbonyl compounds in H2O efficiently increase the long-lastingness of volatile aldehydes and ketones (R 1R2C=O) in various perfumery applications. The hydrazones are usually obtained in an (E) configuration at the imine double bond (NHN=C) and, in the case of aliphatic acylhydrazones R′CO-NH-N=CR 1R2 (R′ = alkyl), as syn and anti conformers with respect to the amide bond (CO-NHN). An average free-energy barrier of ca. 78kJ/mol was determined for the amide-bond rotation by variable-temperature 1H-NMR measurements (Fig. 2). In the presence of H2O, the hydrazone formation is entirely reversible, reaching an equilibrium composed of the hydrazine derivative, the carbonyl compound, and the corresponding hydrazone. Kinetic measurements carried out by UV/VIS spectroscopy showed that the same equilibrium was reached for the formation and hydrolysis of the hydrazone. Rate constants are strongly pH-dependent and increase with decreasing pH (Table 1). The influence of the hydrazine structure on the rate constants is less pronounced than the pH effect, and the presence of surfactants reduces the rate of equilibration (Tables 1 and 3). The full reversibility of the hydrazone formation allows to prepare dynamic mixtures by simple addition of a hydrazine derivative to several carbonyl compounds. Dynamic headspace analysis on dry cotton showed that the presence of a hydrazine derivative significantly increased the headspace concentrations of the different carbonyl compounds as compared to the reference sample without hydrazine (Table 4). The release of the volatiles was found to be efficient for fragrances with high vapor pressures and low H2O solubility. Furthermore, a special long-lasting effect was obtained for the release of ketones. The simplicity of generating dynamic mixtures combined with the high efficiency for the release of volatiles makes these systems particularly interesting for practical applications and will certainly influence the development of delivery systems in other areas such as the pharmaceutical or agrochemical industry.
- Levrand, Barbara,Fieber, Wolfgang,Lehn, Jean-Marie,Herrmann, Andreas
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p. 2281 - 2314
(2008/03/29)
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- USE OF DYNAMIC MIXTURES FOR A CONTROLLED RELEASE OF FRAGRANCES
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The present invention relates to a delivery system in the form of a dynamic mixture obtained by reacting together, in the presence of water, at least one hydrazine derivative with at least one perfuming, flavoring, insect repellent or attractant, bactericide and/or fungicide aldehyde or ketone. The invention's mixture is capable of releasing in a controlled and prolonged manner said aldehyde or ketone in the surrounding environment. Furthermore, the present invention concerns also the use of said dynamic mixtures as perfuming ingredients as well as the perfuming compositions or perfumed articles comprising the invention's mixtures.
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Page/Page column 28
(2008/06/13)
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- Iridium-catalyzed selective N-allylation of hydrazines
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A highly chemo- and regioselective iridium-catalyzed allylic amination is described. The reaction of various hydrazones and hydrazides with allylic carbonates proceeds at ambient temperature in the presence of an [Ir(COD)Cl]2/pyridine catalyst,
- Matunas, Robert,Lai, Amy J.,Lee, Chulbom
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p. 6298 - 6308
(2007/10/03)
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