Cu(OAc)2·H2O-catalyzed N-arylation of nitrogen-containing heterocycles

In the absence of any additional ligands, the efficient N-arylation of nitrogen-containing heterocycles with aryl iodides catalyzed by relative low catalyst amount of Cu(OAc)₂·H₂O was developed. This simple catalytic system is involved in the C-N cross-coupling reaction and works for a variety of pyrazole, pyrrole, imidazole, triazole, indole, benzoimidazole, benzotriazole, carbazole, and anilines as well as aryl iodides with different electronic properties. Highly efficient copper(II)-catalyzed N-arylation protocol was established.     

Synthesis and crystal structures of halogenated oxathiazolones and an unexpected propanamide

The known 1,3,4-oxathiazol-2-ones with crystal structures reported in the Cambridge Structural Database are limited (13 to date) and this article expands the library to 15. In addition, convenient starting materials for the future exploration of 1,3,4-oxathiazol-2-ones are detailed. An unexpected halogenated propanamide has also been identified as a by-product of one reaction, presumably reacting with HCl generated in situ. The space group of 5-[(E)-2-chloroethenyl]-1,3,4-oxathiazol-2-one, C₄H₂ClNO₂S, ( 1 ), is P2₁, with a high Z′ value of 6; the space group of rac-2,3-dibromo-3-chloropropanamide, C₃H₄Br₂ClNO, ( 2 ), is P2₁, with Z′ = 4; and the structure of rac-5-(1,2-dibromo-2-phenylethyl)-1,3,4-oxathiazol-2-one, C₁₀H₇Br₂NO₂S, ( 3 ), crystallizes in the space group Pca2₁, with Z′ = 1. Both of the structures of compounds 2 and 3 are modeled with two-component disorder and each molecular site hosts both of the enantiomers of the racemic pairs (S,S)/(R,R) and (R,S)/(S,R), respectively.     

Pnictogen-Bridged Diphenyl Sulfones as Photoinduced Pnictogen Bond Forming Emission Motifs

In this study, pnictogen (Pn)-bridged diphenyl sulfones were synthesized as motifs for photoinduced dynamic rearrangement. The newly synthesized sulfones exhibited dual fluorescence at 298 K. Density functional theory calculations revealed that the longer-wavelength fluorescence was derived from the geometries after structural relaxation through photo-driven pnictogen bond formation between the O atom lone pair of the sulfonyl moiety and the antibonding orbital of the Pn−C bond. This is the first report on emission dynamics driven by pnictogen bond formation upon photoexcitation.     

Cycloaddition Reactions of Enamines

This review includes information for around two last decades on cycloaddition reactions of enamines with various agents in order to build carbo- and heterocycles. In addition, the review presents organo-catalytic reactions in which enamines are intermediate products generated in situ. This review covers the synthesis of four, five, six and eight-membered carbocyclic compounds, as well as heterocycles as pyrroles, pyridines, etc.