The first N-heterocyclic carbene (NHC)-catalyzed [3+4] cycloaddition of azomethine imines and enals is disclosed. Oxidative catalytic remote activation of enals affords 1,4-dipolarophile intermediates that react with 1,3-dipolar azomethine imines to generate dinitrogen-fused seven-membered heterocyclic products with high optical purities. Our approach also provides effective kinetic resolution ...

The palladium catalytic system was first applied to 2-arylquinazoline synthesis via hydrogen transfer methodology. Various (E)-2-nitrobenzaldehyde O-methyl oximes reacted easily with alcohols or benzyl amines to provide N-heterocyclic compounds in good to high yields. Similarly, the heterocyclic products could be prepared by the reaction of 1-(2-nitrophenyl)ethanone, urea and benzyl alcohols. I...

Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H4NH. It is a colourless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., N-methylpyrrole, C4H4NCH3. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme. A heterocyclic compound i...

7-Dimethyl-amino-2-phenyl-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amine crystallized with one mol-ecule of methanol to give the title compound, C(12)H(13)N(7)·CH(3)OH. The triazolo[1,5-a][1,3,5]triazine heterocyclic core is essentially planar as are both amino groups that are involved in π-electron delocalization with the triazolo[1,5-a][1,3,5]triazine nucleus. The methyl groups of the dimethyl-a...

Mineralization studies were performed to examine the impact of N deprivation on microbial utilization of the N-heterocyclic herbicides, atrazine and cloransulam-methyl (C-M). Soil depleted by 130 years of cropping to Zea mays without fertilization was contrasted to soil from the same site regularly receiving fertilizers. Long-term N deprivation promoted rapid degradation of atrazine and the C-M...

The phosphine-catalyzed [3 + 2]-cycloaddition of 5-methylenehydantoins 4 with the ylides 5, derived from addition of tributylphosphine to the 2-butynoic acid derivatives, 6a-d, gives spiro-heterocyclic products. The camphor sultam derivative 6b gives optically active products. Noteable was that the ylides derived from ethyl 2-butynoate and the 3-(2-butynoyl)-1,3-oxazolidin-2-one derivatives 6c ...

In the title compound, C(16)H(17)FN(2)O(4)·H(2)O, the dihedral angle between the heterocyclic ring and the benzene ring is 5.77 (9)°, that between the heterocycle and the ethoxy-carbonyl plane is 15.5 (1)°, and that between the heterocyclic ring and the cyclopropane ring is 67.75 (13)°. In the crystal structure, mol-ecules are linked into a ribbon-like structure along the c axis by N-H⋯O and O-...

The development of new ROMP-derived silica-immobilized heterocyclic phosphate reagents and their application in purification-free protocols is reported. Grafting of norbornenyl norbornenyl-functionalized (Nb-tagged) silica particles with functionalized Nb-tagged heterocyclic phosphate monomers efficiently yield high-load, hybrid silica-immobilized oligomeric heterobenzyl phosphates (Si-OHBP) an...

Oxazolones are five membered heterocyclic compounds containing nitrogen and oxygen as hetero atoms. The C-2 and C-4 positions of the oxazolone are crucial for their various biological activities. N-substituted oxazolones also participated in variety of intermolecular reactions. Considering these properties, various research workers have shown a keen interest in this small heterocyclic moiety as...

This tutorial review compiles the advances that have been achieved in using transition metal complexes containing N-heterocyclic carbene ligands as components for materials. Applications of metal carbene complexes in fields different from catalysis are remarkably scarce. During the last few years, promising results have been accomplished in particular by utilizing such complexes as antimicrobia...