Current Organic Chemistry - Volume 28, Issue 2, 2024

Electrochemical reduction of organic compounds in the presence of carbon dioxide results in the fixation of carbon dioxide into the substrates with carbon-carbon bond forming reaction to yield the corresponding carboxylic acids. The reaction is called “electrochemical carboxylation” or “electrocarboxylation”. Various kinds of carboxylic acids have been synthesized using carbon dioxide as a carboxyl group source by electrochemical carboxylation. In this mini-review, several representative kinds of carboxylic acids synthesized from carbon dioxide by electrochemical carboxylation are briefly summarized/introduced, comparing past and latest.

Oligomeric compounds can be considered from two points of view: polymer chemistry often sees them as undesired by-products of polymerization processes or, more fruitfully, synthesizes them as structural models for polymers, while organic chemistry synthesizes oligomers, with a typical bottom-up approach, starting from the respective monomers. Conjugated oligomers play a fundamental role in the field of organic semiconductors and therefore in the field of industrial and high-tech applications. Electrochemistry can make a significant contribution to the field of oligomers by rendering the syntheses more expeditious in comparison with the classical organic ones. The electrochemical approach may offer several advantages over the traditional organic synthesis. For example, cleaner and more sustainable syntheses and simpler and shorter synthetic pathways. This review outlines the application of electrochemistry techniques in the synthesis of oligomers.

Sodium sulfinates have been widely utilized as sulfonyl radical precursors for preparing a diverse array of value-added sulfur-containing compounds (sulfones, sulfonamides, sulfonates, thiosulfonates, etc.) through S-C, S-N, S-O and S-S bonds formation reactions. Organic electrosynthesis has become an attractive alternative to conventional methods for redox reactions because it utilizes electric current instead of chemical redox agents. As such, the electrochemical generation of sulfonyl radicals from sodium sulfinates and their applications in organic electrosynthesis have attracted much attention. In this review, the recent advances in the electrochemical sulfonylation of organic compounds involving sodium sulfinates as sulfonyl radical precursors since 2015 were reviewed, along with related reaction mechanisms.

The focus of this review is on the synthetic routes available for different types of pyrazoloquinoline derivatives. There are three types of synthetic methods: i) from pyrazole derivatives; ii) from quinoline derivatives; and iii) miscellaneous methods. The position of the linkage between pyrazole and quinoline rings determines the seven isomers of pyrazoloquinolines. The purpose of this review is to provide a guide for both synthetic and medicinal chemists to discover and design new pyrazoloquinolines for medical purposes.

Tetrazole is a most versatile pharmacophore of which more than twenty FDAapproved drugs have been marketed globally for the management of various diseases. In spite of many remarkable and consistent efforts having been made by the chemists towards the development of greener and sustainable strategies for the synthesis of tetrazole derivatives, this approach still needs more attention. The present review focuses on the green synthetic approach for the preparation of tetrazole derivatives from different starting materials such as nitrile, isonitrile, carbonyl, amine, amide, oxime and terminal alkyne functions. The mechanism of tetrazole synthesis from different substrates is discussed. In addition to this, a four component Ugi-azide reaction to the tetrazole synthesis is also described. Of note, the present articles exploited several water-mediated and solvent-free methodologies for tetrazole synthesis. The important key features of tetrazole synthesis were pinpointing in each synthetic scheme which provides excellent guide to those searching for selective procedure to achieve the desired transformation. This review seeks to present a timely account (2011-2023) on the splendid array of ecofriendly procedures of synthesis known today for the preparation of tetrazole derivatives from different starting materials. The rational of this review is to enlighten recent advancements in the synthesis of tetrazole derivatives from different substrates.