The potential energy surfaces of acetyl cyanide and its functional isomer acetyl isocyanide in their electronic ground state have been investigated using ab initio molecular orbital MP2(FU)/6-311G** and QCISD(T)/6311G** calculations. The molecular eliminations of CH3COX (X ) CN,NC) to CH3X + CO, HX + CH2CO, and CH2 + HCOX, the unimolecular rearrangements to CH3C-OX and CH3O-CX carbenes, 1,3-hyd...

Diphenyl-, aryl-a-siloxyand %-furany1 carbenes can be protonated by even weak proton donors such as alcohols (by a bimolecular or by a pre-association mechanism involving more than one alcohol molecule) to yield the corresponding carbenium ions, whose spectra and electrophilic patterns of behavior are described. INTRODUCTION Proton transfer reactions to and from heteroatoms (= "normal" Bronsted...

Carbenes play a key role in plethora of organic transformations. Although stabilized diazo carbonyl compounds predominate as source electrophilic carbenes, the hazardous nature nonstabilized analogues calls for their situ generation from stable precursors. Among these, 1,3,4-oxadiazolines serve diazoalkane surrogates under UV light irradiation. In view high stability, diverse reactivities, and ...

Reaction of the lithiated N-heterocyclic carbene [:C[N(2,6-(i)Pr2C6H3)]2(CH)CLi]n (LiIPr) with KO(t)Bu in diethylether (Et2O) afforded the novel organo-potassium compound [:C[N(2,6-(i)Pr2C6H3)]2(CH)CK(THF)2] (KIPr·2THF). Both LiIPr and KIPr can be interpreted as ditopic carbanionic carbenes (or alkali metal salts of anionic "dicarbenes") and are interesting precursors for the synthesis of novel...

This publication describes a highly selective oxidation of aldehydes to the corresponding acids or esters. The reaction proceeds under metal-free conditions by using N-heterocyclic carbenes as organocatalysts in combination with environmentally friendly oxygen as the terminal oxidation agent.

A Sc NHC complex readily activates three equivalents of CO2 showing 'Frustrated Lewis Pair' type reactivity with each metal-carbene bond, but whilst CS2 is also activated by the labile carbenes, no metal involvement is observed.

Fluorophore tagged N-heterocyclic carbenes and the derived (NHC)Pd(allyl)Cl complexes were synthesized and the fluorescence signal was used to follow the course of a Suzuki coupling reaction.

The synthesis of deoxy-Breslow intermediates in their oxidized form has been developed via the reaction of N-heterocyclic carbenes (NHCs) with chalcones. Moreover, the initial tetrahedral adduct formed from the 1,4-addition of NHCs to chalcones is also isolated.

A carbene is a divalent carbon atom linked to two other groups by covalent bonds, and possesses two unshared valence electrons. These electrons can be paired in the same orbital as anti-parallel spins (singlet) represented as σ2 or pπ2 in different orbitals, or as parallel spins (triplet) represented as σ1 pπ1. (Droge and Glorius, 2010). N-Heterocyclic carbenes (NHCs) are singlet carbenes in wh...