Carbene transfer reactions are very important transformations in organic synthesis, allowing the generation of structurally challenging products by catalysed cyclopropanation, cyclopropenation, carbene C-H, N-H, O-H, S-H, and Si-H insertion, and olefination of carbonyl compounds. In particular, chiral and achiral metalloporphyrins have been successfully explored as biomimetic catalysts for thes...

Bimetallic homonuclear iron(II) and ruthenium(II) N-heterocyclic carbene complexes have been synthesized and crystallographically analyzed. As a spacer ligand for interconnecting the two redox-active metal centers, a ditopic carbene ligand has been used that comprises two carbene sites annelated to benzene. Detailed electrochemical and spectroelectrochemical analyses of the bimetallic systems r...

A rhodium-catalyzed carbene transfer to alkynes is reported. Easily available enynones served as the carbene source replacing diazocompounds. The overall process involved a cyclization-cyclopropenation-ring enlargement sequence.

The reaction of [Pt(II)(2-phenylpyridine)(acac)] and benzothiazolium bromide yields the N,S-heterocyclic carbene ligand trans to pyridyl while, surprisingly, a very similar N,N-heterocyclic carbene coordinates predominantly trans to the cyclometallated carbon.

the reaction mechanism between (h2c) and (7, 0), zigzag single-walled carbon nanotubes(zswcnts) on two different orientation of c-c have been studied by semi empirical am!method. the activation barriers of (h2c) adding to (7, 0) zswcnt are computed and compared.the effects of diameters of zigzag swcnt on their binding energies were studied

The dirhodium carbene derived from bis(4-methoxyphenyl)diazomethane and [Rh(tpa)4 ]⋅CH2 Cl2 (tpa=triphenylacetate) was characterized by UV, IR, and NMR spectroscopy, HRMS, as well as by X-ray diffraction. The isolated complex exhibits prototypical rhodium carbene reactivity in that it cyclopropanates 4-methoxystyrene at low temperature. Experimental structural information on this important type...

The carbene-C ,N chelate tetracarbonyl tungsten complex [(CO)4/ W C(Ph)NHC5H4N /-o ] (4), obtained from [(CO)5W / C(Ph)OMe] (3) and o -aminopyridine, reacts with iodine by oxidative decarbonylation to give a single isomer of the carbene-C ,N chelate tricarbonyl dihalogeno tungsten(II) complex [(CO)3I2/ W C(Ph)NHC5H4N /-o ] (5). The analogous reaction of 4 with bromine affords two interconvertin...

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...

Cycloisomerizations of 1,n-enynes catalyzed by gold(I) proceed via electrophilic species with a highly distorted cyclopropyl gold(I) carbene-like structure, which can react with different nucleophiles to form a wide variety of products by attack at the cyclopropane or the carbene carbons. Particularly important are reactions in which the gold(I) carbene reacts with alkenes to form cyclopropanes...

Singlet state structures of small, cyclic hydrocarbons which can result from the addition of molecular dicarbon (C2) to ethyne (HC≡CH) or ethene (H2C=CH2) have been calculated (B3LYP/6311+G(d,p) level of theory), and were found to contain carbene centres. Some structures of analogous boranes (replacement of the carbene centers by BH fragments) were also calculated. The computation of NMR parame...