The complex [RuCp*(C-NH(2))(py)]PF(6) bearing a chelating N-heterocyclic carbene with an NH(2) group (C-NH(2)) is an active catalyst for the H(2)-hydrogenation of ketones, an epoxide, ester and ketimine in basic solution. A maximum turnover frequency of 17,600 h(-1) is achieved under mild reaction conditions (25 °C) and economical use of hydrogen (8 bar) while the TOF of a related complex with ...

The gold-catalyzed, seven-membered ring forming, intramolecular hydroamination of alkynic sulfonamides has been investigated. The protocol, with a semihollow-shaped triethynylphosphine as a ligand for gold, allowed the synthesis of a variety of azepine derivatives, which are difficult to access by other methods. Both alkynic sulfoamides with a flexible linear chain and the benzene-fused substra...

In the title compound, [PdCl(2)(C(21)H(23)N(3)O)(2)], the Pd(II) atom is located on an inversion centre and is coordinated in a slightly distorted square-planar environment by the chloride and N-heterocyclic carbene (NHC) ligands in mutual trans positions. There are several hydrogen-bonding inter-actions, the most significant of which is a hydrogen bond between the amide moiety of the NHC and t...

A silver-free methodology was developed for the synthesis of unprecedented N-heterocyclic carbene ruthenium indenylidene complexes bearing a bidentate picolinate ligand. The highly stable (SIPr)(picolinate)RuCl(indenylidene) complex 4a (SIPr = 1,3-bis(2-6-diisopropylphenyl)imidazolidin-2-ylidene) demonstrated excellent latent behaviour in ring closing metathesis (RCM) reaction and could be acti...

The coordination geometry of the Pd atom in the title compound, [Pd(SCN)(2)(C(46)H(54)N(4)O(6))], is approximately square-planar. The N-heterocyclic carbene (NHC) metallacrown ether ligand binds to the Pd atom in a trans orientation through the carbene C atoms of the two imidazole rings and generates a 25-membered chelate ring. Two mutually trans S-bound thio-cyanate ligands complete the coordi...

[reaction: see text] Palladium(II) complexes bearing a single N-heterocyclic carbene ligand serve as effective catalysts for the aerobic oxidative cyclization of alkenes with pendant sulfonamides. The use of carboxylic acid cocatalysts (AcOH and PhCO(2)H) often leads to significant improvements in catalyst stability and product yield and enables catalytic turnover to be achieved with air, rathe...

Palladium-catalyzed amidation of five-membered heterocyclic bromides that contain multiple heteroatoms was achieved for the first time using the Pd/1 catalyst system. This system allows for efficient access to N-arylated imidazoles, pyrazoles, thiazoles, pyrroles, and thiophenes in moderate to excellent yield. Experimental results and DFT calculations point to the need for electron-rich and esp...

Density functional theory calculations have been used to explore the potential of Fe-based complexes with an N-heterocyclic carbene ligand, as olefin metathesis catalysts. Apart from a less endothermic reaction energy profile, a small reduction in the predicted upper energy barriers (≈ 2 kcal mol(-1)) is calculated in the Fe catalyzed profile with respect to the Ru catalysed profile. Overall, t...

The mechanism and origins of Z-selectivity in olefin metathesis with chelated Ru catalysts were explored using density functional theory. The olefin approaches from the "side" position of the chelated Ru catalysts, in contrast to reactions with previous unchelated Ru catalysts that favor the bottom-bound pathway. Steric repulsions between the substituents on the olefin and the N-substituent on ...

The title compound, C(18)H(16)BrN(3)O(4)S, is a Schiff base ligand of 5-bromo-salicylaldehyde and sulfisoxazole [or N-(3,4-dimethyl-5-isoxazol)sulfanilamide]. The present structure is a zwitterion and is a more precise reinterpretation of the structure which was originally reported by Hämäläinen, Lehtinen & Turpeinen [Arch. Pharm. (1986), 319, 415-420]. The two aromatic rings which make π-π int...