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...

A dinuclear N-heterocyclic carbene (NHC) copper complex efficiently catalyzes azide-alkyne cycloaddition (CuAAC) "click" reactions. The ancillary ligand comprises two 4,5-dimethyl-1,3-thiazol-2-ylidene units and an ethylene linker. The three-step preparation of the complex from commercially available starting compounds is more straightforward and cost-efficient than that of the previously descr...

Functionalization of N-heterocyclic carbenes (NHCs) has an important influence on their stability, Lewis donor, and acceptor properties. In this study, we report on the selective functionalization of a four-membered N-heterocyclic bis-silylene (2,6-Ar2C6H3NSi:)2 (1) (Ar = 2,4,6-iPr3C6H2) with mono-oxygen sources N2O and Me3NO. Treatment of 1 with N2O results in the selective formation of mono-s...

For the first time, synthesis of thioesters starting from enals and thiols has been performed in presence a bulky N-heterocyclic carbene (NHC) as catalyst.

This paper describes the biocatalytic synthesis of new Mannich bases containing various heterocyclic rings (thiazole, furane, thiophene, pyridine) by applying the lipase catalyzed trimolecular condensation of the corresponding heterocyclic aldehydes with acetone and primary aromatic amines, in mild and eco-friendly reaction conditions. The obtained Mannich bases were acylated to their correspon...