The transamination of alkyl-palladium halide N-heterocyclic carbene complexes has enabled the isolation of products that reveal interesting insights into the factors which might be barriers to the development of a palladium-catalysed alkyl-amination reaction.

Single crystals of the title compound bis[bis-(1-ethyl-3-methyl-imidazol-2-yl-idene)silver(I)] 1,5,5,7,11,11-hexa-chloro-2,8-di-oxa-4,6,10,12,13,14-hexa-aza-1λ(5),3,5λ(5),7λ(5),9,11λ(5)-hexa-phospha-tricyclo-[7.3.1.1(3,7)]tetra-deca-1(13),4,7(14),10-tetra-ene-6,12-diide 3,9-dioxide, [Ag(C(6)H(10)N(2))(2)](Cl(6)N(6)O(4)P(6))(0.5), were isolated from the reaction of the silver N-heteocyclic carbe...

The complexes IPrMCl (IPr = 1,3-bis(diisopropylphenyl)imidazol-2-ylidene, M = Cu, 1a; M = Au, 1b), in the presence of one equiv of NaBAr'(4) (Ar' = 3,5-bis(trifluoromethyl)phenyl), catalyze the transfer of carbene groups: C(R)CO(2)Et (R = H, Me) from N(2)C(R)CO(2)Et to afford products that depend on the nature of the metal center. The copper-based catalyst yields exclusively a cycloheptatriene ...

We prepared rhodopsin mutants that contained a single reactive cysteine residue per rhodopsin molecule at position 65, 140, 240, or 316 on the cytoplasmic face. A carbene-generating photoactivatable group was linked by a disulfide bond to the cysteine sulfhydryl group of each of the rhodopsin mutants. The resulting derivative was then light-activated at lambda > 495 nm to form the metarhodopsin...

Reaction of [(((Ad)ArO)(3)tacn)U(III)] (1) or [((Me(3)Si)(2)N)(3)U(III)] (3) with tetramethylimidazol-2-ylidene (Me(4)IMC:) yields novel N-heterocyclic carbene complexes [(((Ad)ArO)(3)tacn)U(III)(Me(4)IMC:)] (2) and [((Me(3)Si)(2)N)(3)U(III)(Me(4)IMC:)] (4). Uranium complexes 2 and 4 represent the first examples of compounds with an N-heterocyclic carbene ligand coordinated to a low-valent uran...

The reaction of an imidazolium salt with LiBEt(3)H afforded triethylborane adduct of imidazol-2-ylidene, which can act as a carbene precursor for the synthesis of a transition metal complex as well as a main group element complex.

A triazolium salt derived N-heterocyclic carbene catalyzes the redox esterification reaction between α-β-unsaturated aldehydes and oximes. The resulting saturated oxime esters were obtained in very good yields for a broad range of aliphatic, aromatic and heteroaromatic substrates.

A polystyrene-linked tris(triazolyl)methanecopper(i) cationic catalyst operates under heterogeneous conditions for the reaction of ethyl diazoacetate (EDA) with an array of substrates. Carbon-hydrogen as well as X-H (X = O, N) functionalization derived from the formal transfer of the carbene moiety (:CHCO2Et) from the copper center and subsequent insertion have been achieved, the reactions perm...

B3LYP calculations have been carried out to study the reaction mechanism of the aminolysis of Fischer carbene complexes of the type (CO)(5)Cr=C(XMe)R (X = O and S; R = Me and Ph). We have explored different possible reaction mechanisms either through neutral or zwitterionic intermediates as well as a general base catalysis assisted by an ammonia molecule. Our results show that the most favorabl...

The first example of a biocatalytic strategy for the synthesis of thioethers via an intermolecular carbene S–H insertion reaction is reported. Engineered variants of sperm whale myoglobin were found to efficiently catalyze this C–S bond forming transformation across a diverse set of aryl and alkyl mercaptan substrates and a-diazoester carbene donors, providing high conversions (60–99%) and high...