Dual C(sp)-H and C(sp)-H Activation of 8-Methylquinoline -Oxides: A Route to Access C7-H Bond.

A Pd(II)-catalyzed regioselective dual C(sp)-H/C7(sp)-H activation and annulation of 8-methylquinoline -oxides with maleimide has been accomplished. The use of -oxide as a weak directing group under Pd(II)-complex catalysis activates the initial C(sp)-H and triggers a relayed, second C7(sp)-H activation. The dual C-H bond activation, [3 + 2]-annulation, facile introduction and removal of the directing group, substrate scope, and functional group diversity are the important practical features.

Palladium Catalysis Enabled Sequential C(sp)-H/C-C Activation: Access to Vinyl γ-Lactams.

A Pd(II)-catalyzed tandem reaction of aliphatic amides with vinylcyclopropanes (VCPs) was accomplished by merging C(sp)-H and C-C activation. The reaction of VCP revealed alkenylation/cyclization, followed by ring opening via C-C cleavage, delivering vinyl γ-lactams with ()-selectivity. The role of ligands, site-selectivity, functional group diversity, mechanistic insight, and synthetic utilities are important practical features.

One-pot C-N/C-C bond formation and oxidation of donor-acceptor cyclopropanes with tetrahydroisoquinolines: access to benzo-fused indolizines.

One-pot C-N/C-C bond formation of donor-acceptor cyclopropanes (DACs) with tetrahydroisoquinolines (THIQs) has been achieved to furnish benzo-fused indolizines. These reactions involve a MgI-catalyzed ring opening of DACs and oxidative annulation using Mn(OAc)·2HO. The substrate scope and functional group diversity are the important practical features.

Site-Selective C8-Alkylation of Quinolines with Cyclopropanols: Merging C-H/C-C Bond Activation.

The site-selective C8-alkylation of quinolines has been accomplished using cyclopropyl alcohols as the alkylating agents and -oxide as a weak chelating group in the presence of Co(III) catalysis via merging C-H/C-C bond activation. The use of cyclopropanol as the alkyl source, Co catalysis, substrate scope, HRMS analysis of the reaction intermediate, and late-stage mutation of drug molecules/natural products are the important practical features.

Expedient (3+3)-annulation of generated azaoxyallyl cations with diaziridines.

Efficient annulation of formed azaoxyallyl cations using a base has been accomplished with diaziridines to provide 1,2,4-triazines at room temperature. The substrate scope, scale up, functional group tolerance and transition-metal free reaction conditions are the important practical features.

Cascade C-H Activation/Annulation of Sulfoxonium Ylides with Vinyl Cyclopropanes: Access to Cyclopropane-Fused α-Tetralones.

Rh-catalyzed weak and traceless directing-group-assisted cascade C-H activation and annulation of sulfoxonium ylides with vinyl cyclopropanes as a coupling partner have been accomplished to furnish functionalized cyclopropane-fused tetralones at moderate temperature. The C-C bond formation, cyclopropanation, functional group tolerance, late-stage diversifications of drug molecules, and scale-up are the important practical features.

Directed C8-H allylation of quinoline -oxides with vinylcyclopropanes sequential C-H/C-C activation.

The Rh(III)-catalyzed C8-allylation of quinoline -oxides has been accomplished using vinylcyclopropanes as an allyl source with excellent diastereoselectivity at room temperature. The C-H/C-C activation, substrate scope and natural product mutation are the important practical features.

CuO nanoparticles catalyzed C-N, C-O, and C-S cross-coupling reactions: scope and mechanism.

CuO nanoparticles have been studied for C-N, C-O, and C-S bond formations via cross-coupling reactions of nitrogen, oxygen, and sulfur nucleophiles with aryl halides. Amides, amines, imidazoles, phenols, alcohols and thiols undergo reactions with aryl iodides in the presence of a base such as KOH, Cs(2)CO(3), and K(2)CO(3) at moderate temperature. The procedure is simple, general, ligand-free, and efficient to afford the cross-coupled products in high yield.