Gold-catalyzed intermolecular oxidation of carboxylates of primary or secondary propargylic alcohols are realized with excellent regioselectivity, which is ascribed to inductive polarization of the C-C triple bond by the electron-withdrawing carboxy group. The gold carbene intermediates thus generated undergo selective 1,2-acyloxy migration over a 1,2-C-H insertion, and the selectivities could ...

N-heterocyclic carbene stabilized phosphinidene IMes·PPh has been used as a bridging ligand to isolate a group of closely related molecules involving all three coinage metal ions. The bis-copper(I) chloride, bis-silver(I) chloride and bis-copper(I) bromide adducts of IMes·PPh crystallize as halide ion bridged octanuclear molecules while the [IMes·PPh](AuCl)2 adduct remains monomeric. These mole...

The title complex, [RuCl(2)(C(25)H(26)N(2))]·CH(2)Cl(2), is best thought of as containing an octa-hedrally coordinated Ru center with the arene occupying three sites. Two Ru-Cl bonds and one Ru-carbene bond complete the distorted octa-hedron. The carbene portion of the ligand is a benzimidazole ring. This ring is connected to the C(6)H(2)(CH(3))(3) arene group by a CH(2) bridge. This leads to a...

Unsaturated bridges that link the two cyclopentadienyl ligands together in strained ansa metallocenes are rare and limited to carbon-carbon double bonds. The synthesis and isolation of a strained ferrocenophane containing an unsaturated two-boron bridge, isoelectronic with a C=C double bond, was achieved by reduction of a carbene-stabilized 1,1'-bis(dihaloboryl)ferrocene. A combination of spect...

The mol-ecular structure of the title compound, [Ni(C(19)H(21)N(2)P)(2)]I(2)·2CH(3)CN, shows two six-membered N-heterocyclic carbene/phosphane chelate rings that form a nearly square-planar coordination geometry around the Ni(II) atom, which lies 0.190 (1) Å above the C(2)P(2) plane. The sum of the bond angles at the Ni(II) atom is 358.68 (6)°, with C-Ni-P bite angles of 82.89 (5) and 84.08 (6)...

Using rational design, an engineered myoglobin-based catalyst capable of catalyzing the cyclopropanation of aryl-substituted olefins with catalytic proficiency (up to 46,800 turnovers) and excellent diastereo- and enantioselectivity (98-99.9%) was developed. This transformation could be carried out in the presence of up to 20 g L(-1) olefin substrate with no loss in diastereo- and/or enantiosel...

Unsaturated [Tp(Me2)Ir(III)] fragments, readily generated from compounds [Tp(Me2)Ir(C(6)H(5))(2)(N(2))], (1a) and [Tp(Me2)Ir(η(4)-CH(2)=C(Me)C(Me)=CH(2)] (1b) (Tp(Me2) = hydrotris(3,5-dimethylpyrazolyl)borate), induce the isomerisation of the polypyridines, 2,2'-bipyridine, 1,10-phenanthroline and 2,2':6'2''-terpyridine, to form complexes that contain the carbene tautomer of these ligands. For ...

In the title compound, [Ru(C(44)H(28)N(4))(C(8)H(5)F(3))], the fluorin-ated alkyl-idene group is bound to a five-coordinate Ru atom, which is located toward the carbene C atom, 0.3301 (5)Å from the least-squares plane of the C(20)N(4) porphyrin core. The Ru=C bond is tilted slightly from the normal to the C(20)N(4) least-squares plane due to steric repulsion between the porphyrinate ligand and ...

Migratory insertion is one of the fundamental processes in organopalladium chemistry. In particular, migratory insertion of a CO ligand and the formation of reactive acylpalladium intermediate is a powerful method for introducing a carbonyl functionality into organic molecules. The catalytic cycle involving such a key step has been developed into one of the most important tools to synthesize va...

In the title compound, [Fe(C11H20N2)2(CO)3], the Fe atom shows a distorted trigonal-bipyramidal geometry with three carbonyl and two carbene ligands. The latter have a cis arrangement, with a C-Fe-C angle of 90.60 (7)°. The Fe atom lies 0.007 (1) Å above the basal plane defined by two carbonyl and one carbene C atoms. The mol-ecular structure is closely related to that of the isomolecular but n...