Syntheses of various classes of fused-imidazoles are reported. The key to their successful synthesis depends on the reaction of N-vinyl-1H-imidazole with the π-deficient compounds under basic conditions. Reaction of the target imidazole with 1,1,2,2-tetracyanoethylene and dimethyl acetylenedicarboxylate afforded pyrrolo[1,2-a]imidazoles. On the other site, reaction of the target imidazole with ...

Kaolin-SO3H as a new solid acid is prepared via reaction of kaolin and chlorosulfonic acid. This natural based catalyst is very inexpensive and easy available. Imidazoles are an important class of heterocycles being the core fragment of different natural products and biological systems such as anti-allergic, anti-inflammatory, analgesic, antifungal, antimycotic, antibiotic, antiulcerative, anti...

Kaolin-SO3H as a new solid acid is prepared via reaction of kaolin and chlorosulfonic acid. This natural based catalyst is very inexpensive and easy available. Imidazoles are an important class of heterocycles being the core fragment of different natural products and biological systems such as anti-allergic, anti-inflammatory, analgesic, antifungal, antimycotic, antibiotic, antiulcerative, anti...

In part A, the effect of varying short-chain alkyl substitution on the spectroscopic properties of cyanine dyes was examined. Molar absorptivities and quantum yields were determined for groups of pentamethine and heptamethine dyes for which the substitution of the indole nitrogen was varied. For both sets of dyes, increasing alkyl chain length did not significantly change quantum yield or molar...

The synthesis of a small family of six electronically and sterically modified 1,3,4-trisubstituted 1,2,3-triazol-5-ylidene gold(I) chloride complexes is described. Additionally, the corresponding trans-[PdBr2(iPr2-bimy)(1,3,4-trisubstituted 1,2,3-triazol-5-ylidene)] complexes are also generated and used to examine the donor strength of the 1,3,4-trisubstituted 1,2,3-triazol-5-ylidene ligands. A...

Pd-catalyzed reaction of N-tosylhydrazones with benzyl halides affords di- and trisubstituted olefins in high yields with excellent stereoselectivity. This coupling reaction is supposed to proceed through a migratory insertion of Pd carbene species.

Asymmetric aldol reactions of α-amino acid derivatives via memory of chirality were developed. Chiral oxazolidones with contiguous tetra- and trisubstituted chiral centers were obtained in 78-94% ee by the asymmetric aldol reaction followed by intramolecular acylation.

al-mcm-41 nanoreactors is found to be a remarkable efficient catalyst for one-pot multicomponent cyclocondensation of benzil, aniline or ammonium acetate and aromatic aldehydes for the synthesis of polysubstituted imidazoles under solvent-free conditions. the reaction was efficiently promoted by 10 mg nano-al-mcm-41 and the heterogeneous catalyst was recycled for four runs in this reaction with...

A chemo-, regio-, and stereoselective iron-catalyzed 1,4-hydroboration of dienes that affords gamma-disubstituted allylboranes has been developed. 1,4-Hydroboration of 2-substituted dienes forms allylborane products with (E)-trisubstituted double bonds exclusively.