Abstract. An organocatalytic enantioselective synthesis of δ‐lactone‐fused 4‐chromanones was demonstrated using 1‐(2‐hydroxyaryl)‐1,3‐butanedione and α,β‐unsaturated aldehydes in the presence of Jørgensen‐Hayashi catalyst. The reaction proceeded through a Michael addition/cycloketalization/hemiacetalization sequence, and the resulting hemiacetals were oxidized into the corresponding lactone derivatives

We report the catalytic reduction of both active esters and amides by selective C(acyl)–X (X = O, N) cleavage to access aldehyde functionality via a palladium‐catalyzed strategy. Reactions are promoted by hydrosilanes as reducing reagents with good to excellent yields and with excellent chemoselectivity for C(acyl)–N and C(acyl)–O bond cleavage. Carboxylic acid C(acyl)–O bonds are activated by 2‐chloro‐4

This review summarizes the progress in the fluorination and fluoroalkylation of electron‐rich systems with diverse fluorine (F) and fluoroalkyl (Rfn) reagents employing hypervalent iodine compounds as initiators in the last few decades. Because of the strong electrophilicity, high oxidizing properties, low toxicity, air and moisture stability, ready availability, ease of handling, and mild reaction

In recent years, oxidative dehydrogenation (ODH) of amines has proven to be an efficient, clean and fundamental route for the synthesis of nitriles. This review focuses on the different types of reactions for the oxidation of amines to nitriles such as transition metal‐catalysis, photoactivation, acceptor dehydrogenation, nitroxyl radical‐mediated, and N,O‐doped mesoporous carbon. Emphasis is placed

Nitrogen heterocycles are important structural subunits that occur widely in bioactive natural products, pharmaceuticals, agrochemicals, dyes, cosmetics, and functional materials. Considering the importance of these useful compounds in modern science, the synthesis of N‐heterocycles and their derivatives has always been a hot topic in organic synthesis. Recently, arenediazonium salts which can be easily

Site‐selective ring‐opening process of two different aziridine classes with hydroperoxide is described herein that provides access to various α‐ and β‐amino and α‐(imino)‐peroxy compounds. This strain‐release‐driven peroxide addition to aziridines represents an alternative approach for entries to biologically significant heteroatom substituted organic peroxides and complements existing methods in the

A metal‐free C‐P bond cleavage reaction is described herein. Phosphoramides, a phosphine source, can react with alcohols to produce phosphonate and phosphinate derivatives in the presence of a disulfide. P‐H2, P‐alkyl, and P,P‐dialkyl phosphoramides can be used as substrates to obtain the corresponding pentavalent phosphine products.

An intriguing pyridine−boryl radical‐mediated C−H alkynylation reaction of inactivated alkanes was described. The reaction features mild operation condition and wide substrate scope, and affords the corresponding products in moderate to good yields. Notably, The presence of 4‐cyanopyride N‐oxide was key to the success of the reaction. Cyclohexane are more easily to be functionalized in this reaction

α‐Aminoalkylboronic acids display a distinct role in medicinal chemistry, and their utility has been demonstrated by the successful commercialization of three drugs: bortezomib, ixazomib, and vaborbactam. Just as α‐aminoalkylboronic acids are a bioisostere of α‐amino acids, β‐aminoalkylboronates are a bona fide bioisostere of β‐amino acids, thus they also hold promising potential in drug discovery

The valorization of lignin and its model compounds represents a key technology applied for the production of lignin‐monomers, which constitute as renewable feedstocks and intermediates for the synthesis of value‐added chemicals and fuels as well as molecules related to life science applications. Hence, in addition to lignin‐depolymerization, the effective utilization of lignin‐derived feedstocks such

Oxidative coupling methodology is widely applied for the formation of carbon–carbon and carbon–heteroatom bonds. This review focuses on methods for oxidative sulfonylation of multiple bonds involving sulfonyl hydrazides, sulfinic acids and their salts as S‐reagents. Under oxidative conditions, they generate sulfonyl radicals, trapped by multiple carbon‐carbon bonds resulting in a variety of SO2‐containing

Transition metal‐catalyzed 1,2‐carbohalo‐functionalization reactions of C‐C multiple bonds have emerged rapidly over the past decade as a powerful tool for generating a new carbon‐carbon and carbon‐halogen bond via transposition of an existing carbon‐halogen σ bond. Exploring this highly efficient mode of carbon‐carbon multiple bond difunctionalization, various research groups have established novel

A scalable protocol of direct N‐mono/di‐alkyl/fluoroalkylation of primary/secondary amines has been constructed with various carboxylic acids as coupling agents under the catalysis of a simple air‐tolerant inorganic salt, K3PO4. Advantageous features include 101 examples, 11 drugs and drug‐like amines, fluorinated complex tertiary amines, gram‐scale synthesis and isotope‐labelling amine, thus demonstrating

A visible‐light‐induced site selective C‐H alkylation of heterocyclic N‐oxides with N‐hydroxyphthalimide esters was developed using Eosin Y as the photocatalyst in the presence of Cs2CO3 under redox‐neutral and mild conditions. Using N‐hydroxyphthalimide esters as the radical precursors, quinoline or pyridine N‐oxides were readily coupled with a wide range of primary, secondary, and tertiary radicals

We have developed simple and efficient one‐step protocols for the preparation of a large selection of α‐aminocyclopropyl ketones or benzo[d]imidazoles, by reacting 2‐substituted‐2‐hydroxycyclobutanones with aryl amines or o‐phenylenediamines, respectively. In most case the reactions proceed at room temperature and are catalyst‐free. The formation of benzo[d]imidazoles is rationalized in terms of an