Diastereoselective Construction of Spirocyclic Isobenzofurans via a Tandem Michael Addition/5-Exo-dig Cyclization Reaction.

A practical approach for rapid and efficient access to spirocyclic isobenzofurans is described. The reaction proceeds through the cycloaddition of 1,6-ynenone derivatives and 4-nitro-1,3-diarylbutan-1-ones, promoted by CsCO in the presence of -proline as a catalyst. The advantages of this reaction include the formation of two C-C bonds and one C-O bond as well as mild reaction conditions.

Tosylhydrazide-Induced 1,6-Enyne Radical Cyclization under Copper Catalysis: Access to 3,4-Dihydronaphthalen-1(2)-one Derivatives.

We describe an approach to access 4-aroyl-3-aryl-3,4-dihydronaphthalen-1(2)-one derivatives in 41-79% yields through the Cu-catalyzed radical cyclization/desulfonylation of 1,6-enynes with tosylhydrazide under air conditions. This alternative desulfonylation strategy combines mild conditions, external oxidant-free processes, and sustainability, contributing to more environmentally friendly organic synthesis. The mechanistic studies showed that the CuCl/O combination serves as the source of the oxygen atom needed to form the C═O bond.

Mn-Mediated Direct Regioselective C-H Trifluoromethylation of Imidazopyridines and Quinoxalines.

A simple and highly efficient strategy has been developed for direct C-H trifluoromethylation at C-3 of imidazopyridines and C-8 of quinoxalines with readily available Langlois reagent through KMnO/AcOH system. This protocol showed broad substrate scope and afforded moderate-to-excellent yields of both products. It is the first report that the functionalization of quinoxalines occurred regioselectively at the C-8 position of quinoxalines.

Chemoselective Reduction of α,β-Unsaturated Carbonyl Compounds via a CS/BuOK System: Dimethyl Sulfoxide as a Hydrogen Source.

A novel and practical approach to access saturated ketones from unsaturated ketone derivatives via a CS/BuOK system in dimethyl sulfoxide (DMSO) is reported. The generation of xanthate salt through the reaction of carbon disulfide and potassium -butoxide is essential to this transformation. Deuterium-labeling experiments demonstrated that DMSO can act as a hydrogen donor.

Smart arginine-equipped polycationic nanoparticles for p/CRISPR delivery into cells.

An efficient and safe delivery system for the transfection of CRISPR plasmid (p/CRISPR) into target cells can open new avenues for the treatment of various diseases. Herein, we design a novel nonvehicle by integrating an arginine-disulfide linker with low-molecular-weight PEI (PEI) for the delivery of p/CRISPR. These PEI-Arg nanoparticles facilitate the plasmid release and improve both membrane permeability and nuclear localization, thereby exhibiting higher transfection efficiency compared to native PEIin the delivery of nanocomplexes composed of PEI-Arg and p/CRISPR into conventional cells (HEK 293T).

Assembly of Indole Cores through a Palladium-Catalyzed Metathesis of Ar-X σ-Bonds.

We describe the development of a new method for construction of highly substituted indole scaffolds through the strategic utilizing of the metathesis of Ar-X σ-bonds based on the dynamic nature of palladium-based oxidative addition/reductive elimination. A suitable and simple catalytic system has provided an appropriate platform for a productive ligand exchange and consecutive carbopalladation/C-H activation/amination of phosphine ligands with alkynes and aromatic/aliphatic amines for construction of structurally diverse indoles.

Divergent Synthesis of α-Aroyloxy Ketones and Indenones: A Controlled Domino Radical Reaction for Di- and Trifunctionalization of Alkynes.

Three different modes of aldehyde/alkyne assembly through a controlled radical reaction are devised. While a double C-H activation/annulation leads to indenones, a concurrent oxidation of both aldehydes and alkynes in the course of their connection offers aroyloxy ketones. Besides two types of cascade reactions starting from identical materials, through a phenylpropiolic acid substrate, a cascade three C-C bond formation via an uninterrupted C-H functionalization/annulation/decarboxylative aroylation as a formidable challenge in radical reactions occurs to deliver 2-aroyl-3-aryl indenones.