Advanced Synthesis & Catalysis最新文献

We report the synthesis of 1,3-oxazole-substituted 2-naphthols and phenols from aryl heterobenzyl ethers via Claisen rearrangement by employing a Lewis acid-based ionic liquid as a promoter. Heterobenzyl-2-naphthyl ethers bearing electron-donating and -withdrawing groups produced exclusively [3,3]-sigmatropic Claisen rearranged products in excellent yields under the standard reaction conditions. Meanwhile, aryl heterobenzyl ethers bearing electron-donating and -withdrawing groups produced a mixture of rearranged products via [1,3] or [3,3]-Claisen or para-Claisen rearrangement. We also demonstrated a gram-scale reaction for this methodology. The reported ionic liquid can be reused for the subsequent cycles.

This review provides a comprehensive overview of asymmetric Negishi and Kumada crosscoupling reactions, covering key developments from the 1980s through 2025. It examines enantioselective and enantiospecific variants catalyzed by nickel, palladium, and cobalt complexes. The review discusses reaction scope, mechanistic ligand design and mechanistic understanding have enabled increasingly challenging transformations with high enantioselectivity Overall, this review demonstrates the power and versatility of asymmetric Negishi and Kumada couplings as valuable tools for constructing chiral molecules.

Organocatalyzed Chemoselective Oxidation

The cover uses the archery process as a metaphor, depicting the scene of the shooter selectively shooting arrows towards three different targets, symbolizing the selectivity of the chemical process. The bow is composed of the catalyst, providing the driving force; Arrows represent reaction materials, while different targets correspond to different products. Under the combined action of light and catalyst, by adjusting the reaction conditions (such as oxidant, reaction solvent), three different types of products can be generated respectively. More information can be found in the Research Article by Jichang Liu, Donghui Wei, Ning Liu, and co-workers (10.1002/adsc.70303).

In this study, we have synthesized a series of neutral and cationic silver complexes bearing two different redox-active N-heterocyclic carbene (NHC) ligands. Neutral complexes of the type Nq(IDipp)AgOCOR (R = CH₃ (2b), Ph (2c), CF₃ (2d)) were obtained via the reaction of imidazolium salts or the corresponding free carbenes with silver precursors. In contrast, cationic complexes of the general formula [Nq(NHC)₂Ag)]X (NHC = IDipp, X = BF₄ (3a), SbF₆ (3b); NHC = IMes, X = BF₄ (3c), SbF₆ (3d)) were prepared using AgX salts. The complex Nq(IDipp)AgOCOCH₃ (2b) was used as a catalyst for the carboxylative cyclization of substituted propargyl amines with CO₂ gas and outperforms the nonredox active NHC-silver complexes. This transformation enabled the development of a new and efficient catalytic protocol for the synthesis of a broad range of oxazolidine-2-ones in good to excellent yields. Notably, catalyst 2b exhibited excellent catalytic performance under mild conditions, operating effectively at low CO₂ gas concentrations and in the absence of bases or additives.

In this work, we describe how N-hydroxyphthalimide (NHPI), also under catalytic amounts, promotes hydrogen atom transfer (HAT) from alcohols under electrochemical conditions through the generation of phthalimide-N-oxyl (PINO). In contrast with the well-known electrochemical oxidation to their corresponding aldehydes or ketones, α-alkoxy radicals were successfully coupled with oximes promoting a carbon–carbon bond-forming event. This method allows the α-functionalization of primary and secondary alcohols under simple, straightforward, and mild electrochemical reaction conditions in a single operation even in the presence of catalytic amounts of the HAT catalyst.

An electrochemical migratory cyclization of N-acylsulfonylimine readily generates the biologically interesting sulfonylimine-functionalized benzothiazine. The implementation of continuous flow electrolysis further enhances reaction efficiency and enables gram-scale synthesis of this heterocyclic framework, providing the material basis for future biological activity studies. In addition, a straightforward electrochemical entry to the previously inaccessible benzothiazepine from N-arylsulfonyl benzothioamide is developed.

The combination of photocatalysis and nickel catalysis has been effectively utilized in the esterification of carboxylic acids with aryl halides. In this work, we present an approach where the esterification of carboxylic acids with aryl halides is achieved without an external photocatalyst. An air-stable Ni(II) complex and mild organic base are employed in the protocol, allowing for the esterification of aryl bromides and less reactive aryl chlorides with carboxylic acids. The method is also compatible with a variety of carboxylic acids, including formic acid and N-protected amino acid derivatives. Mechanistic investigations indicate that the carboxylic acid likely coordinates with nickel, and the homolysis of the NiO bond is the key step for couplings before undergoing a Ni(I)−Ni(III) catalytic cycle.

Indoles represent a privileged scaffold in organic and medicinal chemistry, prompting continuous efforts toward efficient and versatile synthetic methodologies. In this review, we present a focused survey of recent advances (2020–2025) in the transition-metal-catalyzed synthesis of indoles from alkynes and nitrogen sources. Both intra- and intermolecular strategies are discussed, highlighting key developments involving cobalt, copper, gold, nickel, palladium, platinum, silver, rhodium, and ruthenium catalysts. Attention is given to mechanistic insights, with detailed discussions provided where necessary to enhance the reader's understanding of the underlying transformations. While this is not an exhaustive compilation of all literature available in the period, we emphasize the most representative and innovative contributions, acknowledging that space limitations may have excluded some high-quality studies. This review aims to offer a clear and accessible overview of state-of-the-art methodologies, serving as a valuable resource for researchers interested in the design and application of indole-forming processes from readily available alkynes and nitrogen-containing precursors.

A visible-light-catalyzed chlorosulfonylation reaction of gem-difluoroalkenes has been successfully developed using sulfonyl chloride as both the sulfonyl group and chlorine source. The reaction proceeds under mild, additive-free conditions, generating α,α-difluoromethyl-β-chlorosulfones with excellent regioselectivity and broad substrate scope. The β-chlorosulfone product serves as versatile intermediate, readily converting into valuable derivatives such as β-azido sulfone. This method provides rapid access to functional fluorinated scaffolds relevant to medicinal chemistry.

Despite notable advances achieved in the classic phosphine catalyzed allene–alkene [3 + 2] annulations, the scope of allenes mainly restrict to allenoates that bearing electron-donating or neutral γ-substituents. Reaction profile of electron-withdrawing group-substituted allenoates (e.g. allene-1,3-dicarboxylates (ADCs)) remained elusive yet in both symmetric and asymmetric patterns. Herein, we present a (S)-SITCP-catalyzed [3 + 2] reaction of ADCs with rhodanine-derived alkenes, providing efficient access of chiral spiro[rhodanine-cyclopentene] derivatives in good yields (up to 98%) with excellent enantio- (up to 99% ee) and diastereoselectivity (up to > 20:1 dr). Notably, ADCs exhibited unparalleled reactivity and enantioselectivity against their γ-electron-donating or neutral substituted analogs in this reaction.