DURING A STUDY on the metabolism of histidine in a child affected with histidinemia (Beauvais, P., and Humbel, R., to be published), we became interested in the chromatography of imidazoles. In this disease the urine contains numerous imidazoles: histidine and its metabolites, imidazole-pyruvic, imidazole-lactic and imidazole-acetic acids and N-acetylhistidine.’I developed a chromatographic met...

Various tetrasubstituted pyrroles/pyrazoles have been prepared from nitro-substituted 1,3-enynes with aromatic amines/hydrazines via a copper-catalyzed cascade aza-Michael addition, cyclization and aromatization at room temperature. This protocol is also effective for the synthesis of tetrasubstituted pyrazoles in high yields.

A facile solid phase synthesis of 2,4,6,7-tetrasubstituted pyrrolo[2,3-d]pyrimidines is described. The synthesis involves a highly efficient five-step route starting from resin-bound dimeric peptoids. To demonstrate the versatility of our method, a representative library of 108 tetrasubstituted pyrrolo[2,3-d]pyrimidines of high quality was synthesized.

A series of tetrasubstituted aromatics has been synthesized, many of which are based on elaborated N-methyliminodiacetic acid (MIDA)-boronates. A sequence employing nitration, bromination, stepwise Suzuki-Miyaura (SM) coupling with a boronic acid, then base-mediated unmasking of the boronic acid from the MIDA-boronate and a second SM-coupling has led to our desired, mainly 1,2,4,5-substituted t...

A novel protocol for the synthesis of tetrasubstituted olefins through a biomimetic approach has been explored. Both mono- and diarylations were performed under ambient oxygen pressure, giving a range of highly hindered tetrasubstituted alkenes. For diarylation of disubstituted substrates, it was demonstrated that the second arylation is the rate-limiting step of the overall transformation.

Disubstituted imidazoles were prepared by reacting appropriate phenylglyoxal with different aryl aldehydes in the presence of ammonium acetate. Trisubstituted imidazoles were prepared by reacting disubstituted imidazoles with chlorobenzene in the presence of catalytic amount of triethylamine (TEA). The synthesized compounds were characterized on the basis of IR, 1H-NMR and mass spectral data an...

An efficient method for the synthesis of 2,3,5,6-tetrasubstituted tetrahydropyrans has been developed from the reaction of aldehydes and ethyl 2-(1-hydroxyalkyl/hydroxy(phenyl)methyl)-5-methylhex-4-enoate using (3,5)-oxonium-ene reaction promoted by boron trifluoride etherate in good yields under mild conditions.

Some functionalized 1,2,4,5-tetrasubstituted imidazole derivatives were synthesized using a one-pot, four component reaction involving 1,2-diketones, aryl aldehydes, ammonium acetate and substituted aromatic amines. The synthesis has been efficiently carried out in a solvent free medium using β-cyclodextrin-propyl sulfonic acid as a catalyst to afford the target compounds in excellent yields. T...

BACKGROUND Azaheterocycles are an important class of compounds because of their highly potent medicinal activities, and the imidazole subcategory is of special interest in regard to drug discovery research. FINDINGS An expeditious synthetic protocol of 2-aryl-4-phenyl-1H-imidazoles has been accomplished by reacting phenylglyoxal monohydrate, ammonium acetate, and aldehyde under sonication. Fo...