Chemo- and regioselective reactions of 5-bromo enones/enaminones with pyrazoles.

Reaction of 5-bromo enones with pyrazoles provided a series of unexpected N,O-aminal derivatives, through a 1,4-conjugated addition at the β-carbon of the 5-bromo enones instead of the expected nucleophilic substitution of the bromine. This reaction also furnished the 1,3-regioisomer of the pyrazole. A similar reaction of pyrazoles using 5-bromo enaminones furnished only N-alkylated pyrazoles-with high regioselectivity and at good yields-through nucleophilic substitution of the bromine.

Effect of slight structural changes on the gelation properties of N-phenylstearamide supramolecular gels.

Supramolecular gels present several applications in which the gelator properties are closely dependent on their structure and solvent. Despite this, there are few studies on the effect of the gelation ability of gelators with slight molecular changes. Therefore, N-arylestearamides (in which aryl = phenyl (1), 4-tolyl (2) and 4-acetylphenyl (3)) were evaluated in different solvents.

Synthesis, Crystal Structure, and Supramolecular Understanding of 1,3,5-Tris(1-phenyl-1H-pyrazol-5-yl)benzenes.

Understanding the supramolecular environment of crystal structures is necessary to facilitate designing molecules with desirable properties. A series of 12 novel 1,3,5-(1-phenyl-1-pyrazol-5-yl)benzenes was used to assess the existence of planar stacking columns in supramolecular structures of pyrazoles. This class of molecules with different substituents may assist in understanding how small structural changes affect the supramolecular environment.

Synthesis, effect of substituents on the regiochemistry and equilibrium studies of tetrazolo[1,5-]pyrimidine/2-azidopyrimidines.

An efficient synthesis methodology for a series of tetrazolo[1,5-]pyrimidines substituted at the 5- and 7-positions from the cyclocondensation reaction [CCC + NCN] was developed. The NCN corresponds to 5-aminotetrazole and CCC to β-enaminone. Two distinct products were observed in accordance with the β-enaminone substituent.