Visible‐Light‐Mediated S−H Bond Insertion Reactions of Diazoalkanes with Cysteine Residues in Batch and Flow

Abstract We describe the application of S−H bond insertion reactions of aryl diazoacetates with cysteine residues that enabled metal‐free, S−H functionalization under visible‐light conditions. Moreover, this process could be intensified by a continuous‐flow photomicroreactor on the acceleration of the reaction (6.5 min residence time). The batch and...

5h

Recent Advances in Transition‐Metal‐Catalyzed Oxidative Annulations to Benzazepines and Benzodiazepines

Benzazepines and benzodiazepines, benzofused seven‐membered N‐heterocycles, compose an important family of natural products and pharmaceuticals. Although certainly important and effectives, classical synthetic methods of these cyclic compounds involve methodologies that often require multistep procedures, with generation of waste materials and lack...

5h

An Overview of Water‐Mediated Alkyne Functionalization by Neighboring Group Participation of Carbonyl Groups

Reviewed herein, the progress employing the assistance of a neighboring carbonyl group for alkyne functionalization reactions that are mediated by water. Proper arrangement of these transformations is synthetically worthwhile because it will allow chemists to design straightforward synthetic routes for the construction of complex architectures with...

5h

Propargylic Alcohols as Coupling Partners in Transition‐Metal‐Catalyzed Arene C‐H Activation

Transition‐metal‐catalyzed site selective arene C‐H bond activation concomitant functionalization with various coupling partners gain magnificent attraction in synthetic organic chemistry as complementary to traditional transformations. Mechanistically, these C‐H functionalization approaches involve directing group assisted concerted metalation‐deprotonation...

5h

Ynamides in Free Radical Reactions

Abstract. In this review we present the transformations that have been developed with ynamides and free radicals. These reactions involve carbon‐, heteroatom‐ or even metalloid‐centered radicals and include inter‐ and intra‐molecular reactions. The scope and mechanism of these transformations are discussed in details, including the most recent examples...

5h

α‐Amino Acids Mediated C−C Double Bonds Cleavage in Diastereoselective Synthesis of Aza‐Spirocyclic Pyrazolones

Abstract An efficient and reagent‐free synthesis of highly functionalized aza‐spirocyclic pyrazolones are achieved from easily available α‐amino acids and alkylidene pyrazolones by means of amination, C−C‐double bonds cleavage, and decarboxylative annulation process. These highly diastereoselective reactions are promoted simply by α‐amino acids and...

5h

Semi‐Synthetic Sialic Acid Probes for Challenging the Substrate Promiscuity of Enzymes in the Sialoconjugation Pathway

A series of unusual sialic acid analogs were prepared using an unprecedented semi‐synthetic strategy. Truncation of natural N‐acetylneuraminic acid was followed by diastereoselective carbon backbone reconstruction using Barbier‐type carboligations as well as different functional group interconversions, which provided access to a variety of functional...

2d

Organocatalytic Enantioselective [3+2] Cycloaddition of Azomethine Ylides with 2,4‐Dienals: Construction of Remote Stereogenic Centers via 1,6‐Addition Reaction

A highly regio‐ and stereoselective [3+2] cycloaddition of phthalazinium dicyanomethanides with 2,4‐dienals was achieved with the use of a commercially available MacMillan’s calalyst via LUMO‐lowering activation. The reaction proceeds through 1,6‐additon to linear 2,4‐dienals with high remote control over stereochemistry, affording the cycloadducts...

2d

Recent Advances in Squaramide‐Catalyzed Asymmetric Mannich Reactions

Bifunctional squaramides as a branch of organocatalysts showed powerful strategies in the art of asymmetric synthesis, and they have been proved to be highly efficient and versatile catalysts for constructing complex molecular structures and chiral biologically active compounds. In this review, we summarized recent advances in bifunctional squaramide‐catalyzed...

2d

Metal‐Free Synthesis of (E)‐Vinyl Sulfones via An Insertion of Sulfur Dioxide/1,5‐Hydrogen Atom Transfer Sequence

Abstract A metal‐free three‐component reaction of propargyl alcohols, sodium metabisulfite, and aryldiazonium tetrafluoroborates under mild conditions is described. The reaction proceeds efficiently at room temperature without the need of any catalysts, affording the corresponding (E)‐vinyl sulfones in moderate to good yields with excellent functional...

3d