ConspectusThe chemistry of hydrazones has gained great momentum due to their involvement throughout the evolution of organic synthesis. Herein, we discuss the tremendous developments in both the methodology and application of hydrazones. Hydrazones can be recognized not only as synthetic equivalents to aldehydes and ketones but also as versatile synthetic building blocks. Consequently, they can participate in a range of practical synthetic transformations. Furthermore, hydrazone derivatives display a broad array of biological activities and have been widely applied as pharmaceuticals. Owing to the weak directing group effect of simple aldehydes and ketones in C–H bond functionalizations, the C–H bond functionalizations of hydrazones that have been developed in the past five years represent a significant step forward. These novel transformations open a new door to a broader library of functionalized and complex small molecules. Moreover, a wide range of biologically important N-heterocycles (dihydropyrazol...

Exploration of C–H Transformations of Aldehyde Hydrazones: Radical Strategies and Beyond

This review is devoted to the scientific achievements of the departments of organic chemistry in higher schools of Russia within the past decade.

Modern Trends of Organic Chemistry in Russian Universities

Tetrel, halogen and hydrogen bonds in bis(4-((E)-(2,2-dichloro-1-(4-substitutedphenyl)vinyl)diazenyl)phenyl)methane dyes

Pnicogen, halogen and hydrogen bonds in (E)-1-(2,2-dichloro-1-(2-nitrophenyl)vinyl)-2-(para-substituted phenyl)-diazenes

Photocatalytic Reductive Fluoroalkylation of Nitrones.

A one-step copper-catalyzed reaction of aldehyde-derived N-substituted hydrazones with CCl4 resulted in efficient synthesis of 4,4-dichloro-1,2-diazabuta-1,3-dienes. It was proven that this C–C bond-forming cascade reaction operates via an addition of trichloromethyl radical to the C═N bond of hydrazone followed by a base-induced elimination of HCl. The reaction was found to be very general, as diverse hydrazones possessing various aromatic groups at N-site, as well as aromatic, aliphatic, and heterocyclic substituents at C-site, are capable partners for coupling with a wide range of polyhalogenated compounds (CCl3Br, CBr4, CCl3CN, CCl3COOEt, CCl3CF3, CBr3CF3) to produce a family of functionalized 1,2-diazabuta-1,3-dienes. It was demonstrated that the prepared heterodienes are highly versatile building blocks for straightforward assembly of various valuable acyclic and heterocyclic molecules.

Copper-Catalyzed Transformation of Hydrazones into Halogenated Azabutadienes, Versatile Building Blocks for Organic Synthesis

Dichloro‐Substituted 1,2‐Diazabuta‐1,3‐dienes as Highly Reactive Electrophiles in the Reaction with Amines and Diamines: Efficient Synthesis of α‐Hydrazo Amidinium Salts

Availability of ample genomic data promotes the reevaluation and reestablishment of bacterial taxonomy and evolution. One of taxons under active study is Pectobacteriaceae, a family of Gram-negative bacteria that cause diseases of important agricultural plants. Elucidation of genomic and transcriptomic features of bacterial species facilitates the development of methods to detect and differentiate these pathogens, and to cure and prevent the diseases. Whole-genome and phylogenetic analyses of currently available bacterial genomes of this group suggest the revision of the Pectobacteriaceae taxonomy. The study proposes the formation of two new taxa. Particularly, a group of Pectobacterium strains, forming a monophyletic group similar to P. aquaticum, can be assigned as a separate species. Misclassified strain previously assigned to the genus Brenneria can represent of a new genus. This bacterium seems to be diverged from the common ancestor earlier than the genera of Dickeya, Lonsdalea, Samsonia, Pectobacterium, and Brenneria.

Analysis of updated Pectobacteriaceae sequences highlights the need for taxonomy revisions

Bioinformatic analysis demonstrates the presence of SGNH-domain in the receptor-binding tail spike protein of Pectobacterium bacteriophage PP16. This protein has a modular structure, and the enzymatic part of the tail spike is a subject to horizontal transfer. The experiments with the recombinant protein indicated that the C-part of the tail spike is insufficient for binding with the receptor.

Analysis of tail spike protein of Pectobacterium bacteriophage PP16 reveals the details of the phage adsorption

Phytopathogenic bacteria of genus Dickeya make a substantial contribution to soft rot of essential crops, particularly potatoes. An innovative solution to this problem can be the treatment of seed and ware tubers with bacteriophage suspension. However, most bacteriophages demonstrate a very fine host specificity. This feature is an advantage since the treatment does not effect environmental and commensal bacteria. On the other hand, the phage application requires a precise detection of the pathogen. Dickeya sp. is characterized by an ample variety of species and strain groups, and no diagnostic assays exists to discriminate them. In this regard, we used the BOX-PCR method for quick identifying the diversity of circulating Dickeya strains without genomic sequencing. The results of BOX-PCR fingerprinting are consistent with the current taxonomic distribution of Dickeya sp. The effectiveness of this method was confirmed by the construction of genomic dendrogram and phylogenetic analysis.

Anna Lukianova

Papers

Copper-Catalyzed Transformation of Hydrazones into Halogenated Azabutadienes, Versatile Building Blocks for Organic Synthesis

Dichloro‐Substituted 1,2‐Diazabuta‐1,3‐dienes as Highly Reactive Electrophiles in the Reaction with Amines and Diamines: Efficient Synthesis of α‐Hydrazo Amidinium Salts

Analysis of updated Pectobacteriaceae sequences highlights the need for taxonomy revisions

Analysis of tail spike protein of Pectobacterium bacteriophage PP16 reveals the details of the phage adsorption

First insight on the Dickeya BOX-PCR fingerprints and its suitability for strain clustering