Dicarbonyliridium(I) complexes of pyridine ester ligands and their reactivity towards various electrophiles

Crystal structure and Hirshfeld surface analysis of 4-(3-meth-oxy-phen-yl)-2,6-di-phenyl-pyridine

The title compound, C24H19NO, was obtained via the reaction of (1E,2E)-3-(3-meth-oxy-phen-yl)-1-phenyl-prop-2-en-1-one with ethyl 2-oxo-propano-ate, using NH4I as a catalyst. The compound crystallizes in the monoclinic space group I2/a. In the mol-ecule, the four rings are not in the same plane, the pyridine ring being inclined to the benzene rings by 17.26 (6), 56.16 (3) and 24.50 (6)°. In the crystal, mol-ecules are linked by C-H⋯π inter-actions into a three-dimensional network. To further analyse the inter-molecular inter-actions, a Hirshfeld surface analysis was performed. Hirshfeld surface analysis indicates that the most abundant contributions to the crystal packing are from H⋯H (50.4%), C⋯H/H⋯C (37.9%) and O⋯H/H⋯O (5.1%) inter-actions.

β-Cyclodextrin: a supramolecular catalyst for metal-free approach towards the synthesis of 2-amino-4,6-diphenylnicotinonitriles and 2,3-dihydroquinazolin-4(1H)-one

β-Cyclodextrin, a green and widespread supramolecular catalyst, has been explored as a highly proficient promoter for the metal-free one-pot multi-component synthesis of a vast range of highly functionalized bioactive heterocyclic moiety, 2-amino-4,6-diphenylnicotinonitriles and 2,3-dihydroquinazolin-4(1H)-one, from easily available precursor aldehydes. The main endeavor of these protocols is to explore this organic supramolecule in one-pot multi-component synthesis. Absence of metal catalyst or toxic acid and harsh reaction conditions, excellent functional group tolerance, inexpensive, greener and environmentally safe protocol are the key advantages of this work.

1,6-Addition of vinyl p-quinone methides with cyclic sulfamidate imines: access to 4-hydroxyaryl-2,6-diarylpyridines

A base-promoted 1,6-addition–cyclization reaction of vinyl para-quinone methides with cyclic sulfamidate imines in an open atmosphere is reported. This method delivers good to high yields of 2,4,6-trisubstituted pyridines with a valuable phenolic moiety at the C4-position.

Two new alkaloids isolated from traditional Chinese medicine Binglang the fruit of Areca catechu

Binglang, the fruit of Areca catechu L, has a long history as an important Chinese herbal medicine. Two new alkaloids (1 and 2), along with forty-one known compounds (3-43) were isolated from the dried fruit of Areca catechu L. The structures were elucidated on basis of the IR, UV, MS and 1D, 2D NMR spectroscopic data. Compounds 26 and 33 showed weak cytotoxicity against human gastric cancer cell line (BGC-823) with IC₅₀ of 15.91 μM and 20.13 μM, respectively.

Carbene-catalyzed LUMO activation of alkyne esters for access to functional pyridines

A carbene-catalyzed activation of alkyne ester for quick access to functional pyridines is reported. The reaction involves a previously unexplored unsaturated acyl azolium intermediate bearing a carbon–carbon triple bond that shall exhibit rich chemical reactivities.

Metal-free oxidative cyclization of acetophenones with diamines: a facile access to phenylpyridines

An efficient metal-free access to 2- and 3-phenylpyridines via oxidative coupling of acetophenones with 1,3-diaminopropane has been described.

Visible light-induced aerobic C–N bond activation: a photocatalytic strategy for the preparation of 2-arylpyridines and 2-arylquinolines

An efficient method for accessing arylpyridines and arylquinolines via visible light-induced aerobic C–N bond activation is described.

One-pot synthesis of 2,4,6-triarylpyridines from β-nitrostyrenes, substituted salicylic aldehydes and ammonium acetate

The diversity-oriented synthesis of 2,4,6-trisubstituted pyridines via K₂CO₃-promoted multicomponent reactions of the β-nitrostyrenes, available substituted salicylic aldehydes and ammonium acetate have been developed.

A mild and facile synthesis of polyfunctionalized pyridines: merging three-component cyclization and aerobic oxidation by amine/metal catalysts

A mild and facile synthesis of polyfunctionalized pyridines from NH₄OAc, β,γ-unsaturated α-ketoesters, and ketones/aldehydes has been reported through tandem three-component cyclization and aerobic oxidation using the combination of amine and metal catalysts.