Hydrazone | EPFL Graph Search

Hydrazones are a class of organic compounds with the structure . They are related to ketones and aldehydes by the replacement of the oxygen =O with the = functional group. They are formed usually by the action of hydrazine on ketones or aldehydes. Hydrazine, organohydrazines, and 1,1-diorganohydrazines react with aldehydes and ketones to give hydrazones. Phenylhydrazine reacts with reducing sugars to form hydrazones known as osazones, which was developed by German chemist Emil Fischer as a test to differentiate monosaccharides. Hydrazones are the basis for various analyses of ketones and aldehydes. For example, dinitrophenylhydrazine coated onto a silica sorbent is the basis of an adsorption cartridge. The hydrazones are then eluted and analyzed by HPLC using a UV detector. The compound carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (abbreviated as FCCP) is used to uncouple ATP synthesis and reduction of oxygen in oxidative phosphorylation in molecular biology. Hydrazones are the basis of bioconjugation strategies. Hydrazone-based coupling methods are used in medical biotechnology to couple drugs to targeted antibodies (see ADC), e.g. antibodies against a certain type of cancer cell. The hydrazone-based bond is stable at neutral pH (in the blood), but is rapidly destroyed in the acidic environment of lysosomes of the cell. The drug is thereby released in the cell, where it exerts its function. Hydrazones are susceptible to hydrolysis: Alkyl hydrazones are 102- to 103-fold more sensitive to hydrolysis than analogous oximes. When derived from hydrazine itself, hydrazones condense with a second equivalent of a carbonyl to give azines: Hydrazones are intermediates in the Wolff–Kishner reduction. Hydrazones are reactants in hydrazone iodination, the Shapiro reaction, and the Bamford-Stevens reaction to vinyl compounds. Hydrazones can also be synthesized by the Japp–Klingemann reaction via β-keto-acids or β-keto-esters and aryl diazonium salts.

Cross-Coupling of Alkyl Redox-Active Esters with Benzophenone Imines: Tandem Photoredox and Copper Catalysis

Xile Hu, Runze Mao, Jonathan Balon

Alkyl amines are an important class of organic compounds in medicinal and materials chemistry. Until now very have been very few methods for the synthesis of alkyl amines by metal‐catalyzed cross‐coupling of alkyl electrophiles with nitrogen nucleophiles. ...

2018

Organocatalytic Nucleophilic Addition of Hydrazones to Imines: Synthesis of Enantioenriched Vicinal Diamines

Qian Wang, Jieping Zhu, Yang Wang

In the presence of a catalytic amount of chiral phosphoric acid, nucleophilic addition of N-monosubstituted hydrazones to N-Boc imines affords differentially protected vicinal diamines in the form of b-amino N,N’-dialkyldiazenes in excellent yields with hi ...

Wiley-Blackwell2017

Highly dispersed cobalt oxides nanoparticles on activated carbon fibres as efficient structured catalysts for the transfer hydrogenation of m-nitrostyrene

Paul Joseph Dyson, Lioubov Kiwi, Oliver Anthony Beswick, Alexander Parastaev

The facile preparation of structured catalysts featuring highly-dispersed non-precious metal (Fe, Ni, Co) oxide nanoparticles stabilized within a super-microporous network of activated carbon fibres (ACF) is described. The catalyst morphology was controlle ...

Elsevier Science Bv2017