A photo opportunity: A visible‐light‐excited iridium catalyst delivers electrons from an amine to an organohalide. The electron transfer then induces reductive scission of the carbon–halogen bond, generating the corresponding alkyl, alkenyl, and aryl radical that can undergo cyclization and hydrodehalogenation reactions.

A mild, palladium(II)-catalyzed ring-forming aminoacetoxylation of alkenes is described. Treatment of a range of nitrogen nucleophiles with catalytic palladium(II) in the presence of PhI(OAc)2 as oxidant resulted in alkene aminoacetoxylation, affording a variety of nitrogen-containing heterocycles. Our studies indicate the possibility for high levels of reaction regio- and stereocontrol. It appears that this is a stereoselective trans alkene difunctionalization and thus a useful alternative to related cis-selective, metal-catalyzed alkene aminohydroxylation processes.

Herein we report a highly efficient method for nickel-catalyzed C–N bond formation between sulfonamides and aryl electrophiles. This technology provides generic access to a broad range of N-aryl and N-heteroaryl sulfonamide motifs, which are widely represented in drug discovery. Initial mechanistic studies suggest an energy-transfer mechanism wherein C–N bond reductive elimination occurs from a triplet excited NiII complex. Late-stage sulfonamidation in the synthesis of a pharmacologically relevant structure is also demonstrated.

With their mechanistic novelty and various modalities of reactivity, transition metal unsaturated carbene (alkenylidene) complexes have emerged as versatile intermediates for new reaction discovery. In particular, the past decade has witnessed remarkable advances in the chemistry of metal vinylidenes and allenylidenes, leading to the evolution of a diverse array of new catalytic transformations that are mechanistically distinct from those developed in the previous two decades. This review aims to provide a survey of the recent achievements in the development of organic reactions that make use of transition metal alkenylidenes as catalytic intermediates and their applications to organic synthesis.

A highly stereoselective palladium-catalyzed O-glycosylation reaction is described. The reaction of a glycal 3-acetate or carbonate with the zinc(II) alkoxide of acceptors establishes the glycosidic linkage under palladium catalysis to give rise to disaccharides as the product in good yields and with high stereoselectivity. In contrast to the Lewis acid mediated Ferrier procedure, the anomeric stereochemistry of this reaction is controlled by the employed ligand. Whereas the use of a complex of palladium acetate and 2-di(tert-butyl)phosphinobiphenyl as the catalyst results in the exclusive beta-glycoside formation, the same reaction using trimethyl phosphite ligand furnishes an alpha-anomer as the major product. The utility of the 2,3-unsaturation present in the resulting glycoside is demonstrated by the further transformations such as dihydroxylation, hydration, and hydrogenation reactions. Thus, the combination of the glycosylation and subsequent functionalization provides a novel entry to saccharides which are otherwise difficult to prepare. The broad scope of the process, mildness of the reaction conditions, and experimental simplicity should make this method a useful tool in synthetic carbohydrate chemistry.