A significant number of important acyl-transfer reactions, such as direct acylation, ortho acylation, heteroatom acylation, and a diversity of cyclization reactions using the title compound as a key starting material, have been described in recent years. Just like a sleeping beauty, α-oxocarboxylic acids were awakened from a 17-year sleep to become important reagents in classical and new acylation reactions. The greener characteristic of the coproduct formed in reactions using α-keto acid (only CO 2 ), together with its versatility as a building block in catalytic organic synthesis, accredit it as a candidate to green acylating agent, an alternative to acyl chloride, and other acyl-transfer reagents. This review presents the impressive breakthroughs achieved mainly in the past decade in the development of new catalytic reactions for the formation of C−C, C−N, and C−S bonds using α-keto acids. CONTENTS 1. Introduction 7113 2. Classical Methods and Recent Advances in the Synthesis of α-Keto Acids 7115 2.1. Physical Properties of α-Keto Acids 7119 3. α-Keto Acids in Acylation Reactions 7119 3.1.

Abstract:We describe here an efficient and regioselective synthesis of arylselanyl anilines by coppercatalyzed direct arylselenation of arylamines. Using a catalytic amount of copper iodide in dimethyl sulfoxide at 110 8C under an air atmosphere, a range of arylselanyl anilines was obtained directly from substituted diaryl diselenides in moderate to good yields via C À H bond cleavage of aryl amines.

In the last two decades, the search for sustainability in chemical reactions has attached a lot of attention. In this focus review, the use of ultrasound (US) as an alternative energy source in organic synthesis is presented. The improvement of the performance of chemical reactions due to the cavitation effect has been previously studied and described. The use of US guarantees often higher yields than other green methodologies, as microwave or ball milling. The impressive positive effect of US in organic synthesis are demonstrated in this review mainly in organometallic and multi-component reactions (MCRs), aimed to prepare bioactive compounds. A particular attention is dedicated to the US-assisted synthesis of valuable organochalcogen compounds with pharmacological activity.[a] F.

Organoselenium compounds have been successfully applied in biological, medicinal and material sciences, as well as a powerful tool for modern organic synthesis, attracting the attention of the scientific community. This great success is mainly due to the breaking of paradigm demonstrated by innumerous works, that the selenium compounds were toxic and would have a potential impact on the environment. In this update review, we highlight the relevance of these compounds in several fields of research as well as the possibility to synthesize them through more environmentally sustainable methodologies, involving catalytic processes, flow chemistry, electrosynthesis, as well as by the use of alternative energy sources, including mechanochemical, photochemistry, sonochemical and microwave irradiation.

Bis(indolyl)methanes were efficiently synthesized using ammonium niobium oxalate (ANO) as the catalyst and water or glycerol as the solvent.

C–Se bonds in electron-rich arenes are easily formed by the reaction of bench-stable arylseleninic acids as an electrophilic selenium source. The only waste in the reaction is water.

The selenophene derivatives are an important class of selenium-based heterocyclics. These compounds play an important role in prospecting new drugs, as well as in the development of new light-emitting materials. During the last years, several methods have been emerging to access the selenophene scaffold, employing a diversity of cyclization-based synthetic strategies, involving specific reaction partners and particularities. This review presents a comprehensive discussion on the recent advances in the synthesis of selenophene-based compounds, starting from different precursors, highlighting the main differences, the advantages, and limitations among them.

Ammonium niobium oxalate promotes the reaction of α-phenylglyoxylic acid with o-functionalized anilines for the synthesis of benzothiazoles and benzoxazin-2-ones.