Organocalcium Hydride-Catalyzed Intramolecular C(sp3)-H Annulation of Functionalized 2,6-Lutidines.

This work reports an intramolecular C(sp3)-H annulation of functionalized 2,6-lutidines catalyzed by an organocalcium hydride [{(DIPPnacnac)CaH(thf)}2] (DIPPnacnac = CH{(CMe)(2,6-iPr2-C6H3N)}2). This reaction constitutes a streamlined approach for producing a new family of tetrahydro-1,5-naphthyridines and hexahydropyrido[3,2-b]azocines derivatives in good to excellent yields with high atom efficiency and broad substrates scope. A calcium alkyl complex was isolated from the stoichiometric reaction between calcium hydride and the substrate through deprotonation, which was structurally characterized and confirmed as the catalytic intermediate.

Scandium-Catalyzed Benzylic C(sp3)-H Alkenylation of Tertiary Anilines with Alkynes.

This work describes the chemo- and stereoselective benzylic C(sp3)-H alkenylation of tertiary ortho-methyl anilines with internal alkynes using a simple ß-diketiminato scandium catalyst. This protocol offers an efficient method for the synthesis of a new family of tertiary ortho-allylanilines in high yields. The resultant alkenylation products facilely underwent further chemical transformation to other valuable anilines. A cationic scandium benzyl species was isolated from a stoichiometric reaction and confirmed to be the catalytic intermediate.

Functionalization of Diazo Groups by the Nucleophilic Addition of Two Molecules of a Dimethylsulfonium Ylide to α-Diazo-ß-ketoesters/ketones: Synthesis of Highly Functionalized Hydrazones.

The intrinsic electrophilic feature for the terminal nitrogen of α-diazo-ß-ketoesters/ketones has been elucidated by the intermolecular nucleophilic addition of two molecules of a dimethylsulfonium ylide. This methodology allows for access to highly functionalized hydrazones with a broad scope and good functional group tolerance. The reaction operates under simple and mild conditions without using a catalyst.