Cooperative Gold(I)/DMAP Catalysis Enabled (2 + 3) Cycloadditions of Yne-Enones with Oxindole-Derived MBH Carbonates.

A cooperative gold(I)/DMAP system catalyzes the (2 + 3) cycloadditions of yne-enones with oxindole-derived Morita-Baylis-Hillman (MBH) carbonates, yielding diverse bispiro-cyclopentene oxindole products. The mild, scalable protocol demonstrates broad substrate scope and excellent chemo- and diastereoselectivity. Mechanistic study reveals pivotal roles of both catalysts in the unique (2 + 3) cycloaddition. This strategy showcases superiority in achieving transformation with unique chemoselectivity and excellent diastereoselectivity, unattainable through traditional monocatalytic methodologies.

Construction of Cyclopentanes Consisting of Five Stereocenters via NHC-Catalyzed Cascade Reactions of Enals with Oxindole-Dienones.

Despite the widespread presence of the chiral cyclopentane motif, the asymmetric synthesis of cyclopentanes containing five stereocenters remains a formidable challenge. Here, we present an N-heterocyclic carbene (NHC)-catalyzed cascade reaction of enal and oxindole-dienone, which allows access to spiroxindole cyclopentanes featuring a complete set of chiral centers on the five-membered carbocycle. This strategy, characterized by the formation of multiple bonds and chiral centers, demonstrates a broad substrate scope, exclusive diastereoselectivity, and up to 99:1 er.

Organocatalytic atroposelective synthesis of naphthoquinone thioglycosides from aryl-naphthoquinones and thiosugars.

In this study, we report an organocatalytic formal coupling strategy for aryl-naphthoquinones with thiosugars that provides straightforward access to the axially chiral naphthoquinone thioglycoside with excellent stereoselectivity. Mechanistic studies revealed the key role of H-bonding in stereochemical recognition. The reaction pathway involves the atroposelective addition, followed by stereoretentive oxidation of the hydroquinone intermediate.

Cascade One-Pot Method To Synthesize Isoquinolin-1(2H)-ones with α-Bromo Ketones and Benzamides via Pd-catalyzed C-H Activation.

A cross-coupling strategy of palladium-catalyzed ortho-C-H bond activation and intramolecular addition of N-C annulation to synthesize isoquinolin-1(2H)-ones has been developed. A wide range of α-bromo ketones with different substituents proceeded smoothly in this reaction, and varieties of isoquinolin-1(2H)-one derivatives were obtained in moderate to good yields.