Chemoselective Reduction of α,ß-Unsaturated Carbonyl Compounds via a CS2/t-BuOK System: Dimethyl Sulfoxide as a Hydrogen Source.

A novel and practical approach to access saturated ketones from unsaturated ketone derivatives via a CS2/t-BuOK system in dimethyl sulfoxide (DMSO) is reported. The in situ generation of xanthate salt through the reaction of carbon disulfide and potassium tert-butoxide is essential to this transformation. Deuterium-labeling experiments demonstrated that DMSO can act as a hydrogen donor.

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 KMnO4/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. Mechanistic studies revealed that reaction proceeded via radical pathway.

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 (PEI1.8k) for the delivery of p/CRISPR. These PEI1.8k-Arg nanoparticles facilitate the plasmid release and improve both membrane permeability and nuclear localization, thereby exhibiting higher transfection efficiency compared to native PEI1.8kin the delivery of nanocomplexes composed of PEI1.8k-Arg and p/CRISPR into conventional cells (HEK 293T). This nanovehicle is also able to transfect p/CRISPR in a wide variety of cells, including hard-to-transfect primary cells (HUVECs), cancer cells (HeLa), and neuronal cells (PC-12) with nearly 5-10 times higher efficiency compared to the polymeric gold standard transfection agent. Furthermore, the PEI1.8k-Arg nanoparticles can edit the GFP gene in the HEK 293T-GFP reporter cell line by delivering all possible forms of CRISPR/Cas9 system (e.g. plasmid encoding Cas9 and sgRNA targeting GFP, and Cas9/sgRNA ribonucleoproteins (RNPs) as well as Cas9 expression plasmid andin vitro-prepared sgRNA) into HEK 293T-GFP cells. The successful delivery of p/CRISPR into local brain tissue is also another remarkable capability of these nanoparticles. In view of all the exceptional benefits of this safe nanocarrier, it is expected to break new ground in the field of gene editing, particularly for therapeutic purposes.

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.

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.