Cobalt-Catalyzed Thioamide Directed C(arene)-H Annulation with Ynamide: Regioselective Access to 2-Amidoindenones.

Demonstrated herein is an unprecedented thioamide-directed cobalt (Co)-catalyzed umpolung annulation of sulfoximines enabled aryl thioamide with ynamide for the synthesis of highly substituted 2-amidoindenones. The cyclization is regioselective, making β-C-C and α-C-CO bonds. The transformation is even successful on a gram scale, exhibiting broad scope with labile functional group tolerance and constructing 43 unusual 2-amidoindenones of structural diversity.

A 6--dig Thiolative Cyclization of Yne-Ynamides: Access to Thiodihydropyridin-2-ones.

A straightforward regioselective intramolecular 6--dig cyclization of yne-tethered ynamide is herein developed. The reaction involves an intramolecular enolate attack of ketene--acetals, generated in situ from yne-ynamide and methanesulfonic acid, to the alkyne moiety activated by a sulfonium cation. The transformation enables access to structurally diverse 5-(arylthio)-3,6-dihydropyridin-2(3)-ones with broad functional group compatibility.

Cationic-palladium catalyzed regio- and stereoselective syn-1,2-dicarbofunctionalization of unsymmetrical internal alkynes.

π-Extended tetrasubstituted olefins are widely found motifs in natural products, leading drugs, and agrochemicals. Thus, development of modular strategies for the synthesis of complex all-carbon-substituted olefins always draws attention. The difunctionalization of unsymmetrical alkynes is an attractive approach but it has remained faced with regioselectivity issues.

Gold-Catalyzed Transformation of Ynamides.

Ynamide, a unique species with inherited polarization of nitrogen lone pair electron to triple bond, has been largely used for the developement of novel synthetic methods and the construction of unusual N-bearing heterocycles. The reaction versatility of ynamide on umpolung reactivity, radical reactions and asymmetric synthesis have been recently reviewed. This review provides an overall scenic view into the gold catalyzed transformation of ynamides.

Yb(iii)-catalysed syn-thioallylation of ynamides.

Reported herein is a syn-thioallylation of ynamides incorporating a sulfide moiety at the α-position and an allyl group at the β-position of the ynamide. The transformation is successful under ytterbium(iii)-catalysis, providing access to highly substituted thioamino-skipped-dienes with broad substrate scope. Thus, tetrasubstituted olefins (with four different functional groups: amide, phenyl, thioaryl/alkyl, and allyl on the carbon centers) are made in a single step from readily accessible ynamides, preserving complete atom economy.

Enantioselective Gold(I)-Catalyzed Hydrative Cyclizations of -Propargyl-ynamides into 3,6-Dihydropyridinones.

This study discloses the first enantioselective variant of the gold(I)-catalyzed hydrative cyclizations of ynamides, which have been implemented by using bis-gold(I) complexes of chiral diphosphines. Starting from -propargyl-ynamides and water in the presence of -toluenesulfonic acid, the cyclization reactions afford -tosyl-3,6-dihydropyridin-2(1)-ones in good isolated yields and with high levels of stereocontrol (20 examples, enantiomeric ratios up to 94:6).