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In the presence of catalytic amounts of molecular iodine and stoichiometric potassium persulfate, a green, highly chemoselective, regioselective and cis-selective radical isothiocyano-chalcogenization of alkenes with NH4SCN in water is disclosed. This three component reaction features high selectivities, an environmentally benign process, mild conditions, high yields, excellent functional-group tolerance, and broad substrate scope. The resulting products can be further transformed into other molecules with structural similarities of these compounds to bioactive analogs. [ABSTRACT FROM AUTHOR]

A transition metal-free synthesis of N-(arylthio/seleno)ethyl sulfoxidmines via blue light-promoted radical sulfoximido-chalcogenization of aliphatic and aromatic alkenes was developed. The sulfoximidation process demonstrated high chemoselectivity and allowed a broad substrate scope, completing the sulfoximido-chalcogenization of alkenes in good yields. [ABSTRACT FROM AUTHOR]

A new protocol was developed to synthesize (enantioenriched) thioethers and selenoethers from (chiral) benzylic trimethylammonium salts and di(hetero)aryl disulfides or diselenides. These syntheses were promoted by the presence of weak base and did not require the use of any transition metal, and resulted in the target products with good to excellent yields (72–94%). Using quaternary ammonium salts synthesized from enantiomerically enriched amines led to highly enantiopure benzylic thioethers and selenoethers (94–99% ee) with configurations reversed from those of their enantioenriched quaternary ammonium salts. [ABSTRACT FROM AUTHOR]

A recyclable Amberlyst-15-catalyzed three-component reaction in water was developed to synthesize asymmetric diarylmethyl sulfones in good to excellent yields with a wide substrate scope. Asymmetric diarylmethyl sulfones were prepared via C–C and C–S bond formation in a single step between easily available aryl/alkyl aldehydes, sodium aryl/alkyl sulfinates and tri/dimethoxybenzenes. [ABSTRACT FROM AUTHOR]

The binding interaction of niraparib (MK-4827), a poly(ADP-ribose) polymerase inhibitor, with calf thymus deoxyribonucleic acid (ctDNA) has been explored by various theoretical and experimental techniques. Molecular docking models predicted that all the binding conformations of MK-4827 interaction with DNA are clustered into two types: one intercalates into the middle part of the DNA composed of A–T base pairs, and the other one binds with the bottom part of the DNA composed of C–G base pairs. Molecular dynamics simulations further concluded that MK-4827 could steadily intercalate the A–T base pairs of the DNA structure, and the hydrogen bonds and hydrophobic forces help maintain this combination. Fluorescence titration of MK-4827 by ctDNA indicated that the interaction involves static quenching, which resulted from the temperature dependence of the MK-4827–ctDNA complex and was further verified by fluorescence lifetime experiments. Iodide quenching, DNA melting, viscosity and fluorescence competitive experiments with two known intercalative binders confirmed that intercalation is the main DNA binding mode for MK-4827 and has certain influence on the conformation of the ctDNA as indicated by CD. [ABSTRACT FROM AUTHOR]

N-Aryl-α-amino amides including their chiral isomers have demonstrated important applications as pharmaceutical drugs; however, to date, a one-step synthetic route for them still remains to be developed. Herein, an efficient ligand-free copper-catalyzed selective C–N coupling reaction of diaryliodonium salts and dinucleophiles under mild conditions was realized. Diaryliodonium salts prefer to react with dinucleophiles at the site of stronger alkalic amino groups. Thus, a general aliphatic amino-selective N-arylation of α-amino amides was disclosed. Additionally, copper-catalyzed N-arylation of diaryliodonium salts afforded the same products as obtained via palladium-catalyzed reactions of aryl halides. [ABSTRACT FROM AUTHOR]

A ligand-free CuI-catalyzed cascade C-S and C-N cross coupling of (hetero)aryl ortho-dihalides and ortho-aminobenzenethiols has been developed, and various phenothiazines were synthesized with excellent regioselectivity. A possible mechanism is proposed for the cascade coupling., (This journal is © The Royal Society of Chemistry 2012)