How easy is CO2 fixation by M–C bond containing complexes (M = Cu, Ni, Co, Rh, Ir)?
A comparison between different M–C bonds (M = Cu(I), Ni(II), Co(I), Rh(I) and Ir(I)) has been reported by using density functional theory (DFT) calculations to explore the role of the metal in the fixation or incorporation of CO2 into such complexes.
N-Heterocyclic carbene-catalyzed [4 + 2] annulation of α,β-unsaturated carboxylic acids: enantioselective synthesis of dihydropyridinones and spirocyclic oxindolodihydropyridinones
The N-heterocyclic carbene-catalyzed [4 + 2] annulation of α,β-unsaturated carboxylic acid with hydrazones and isatin-derived imines was developed, affording the corresponding dihydropyridinones, respectively, in good yields with high enantioselectivities.
Organopolymerization of naturally occurring Tulipalin B: a hydroxyl-functionalized methylene butyrolactone
Naturally occurring, OH-containing, tri-functional Tulipalin B has been successfully polymerized by N-heterocyclic carbene and phosphazene superbase catalysts into polymers with Mn up to 13.2 kg mol−1.
Research Article
Rhodium catalysed conversion of carbenes into ketenes and ketene imines using PNN pincer complexes
PNN pincer-type rhodium complexes catalyze ketene and ketene imine synthesis, using CO or an isocyanide and a carbene precursor.
C–H insertions in oxidative gold catalysis: synthesis of polycyclic 2H-pyran-3(6H)-ones via a relay strategy
A new application of oxidatively generated, highly electrophilic α-oxo gold carbenes in synthetically streamlining insertions into unactivated C–H bonds is realized by converting them to putative vinyl cation intermediates in a relay approach. This chemistry permits expedient access to cyclic dihydropyran-3-ones.
Cyclometallated ruthenium(II) complexes with ditopic thienyl–NHC ligands: syntheses and alkyne annulations
Cycloruthenation of thienyl–NHC ligands and subsequent alkyne annulations allow for a facile preparation of unusual aza-heterocyclic-thiophenes.
Diastereoselective synthesis of cyclopentanone-fused spirooxindoles by N-heterocyclic carbene-catalyzed homoenolate annulation with isatilidenes
NHC-catalyzed reaction of enals with N-substituted isatilidenes resulting in the diastereoselective synthesis of cyclopentanone-fused spirooxindoles proceeding via the homoenolate equivalent intermediates is reported.
Catalyst-free cross-coupling of N-tosylhydrazones with chromium(0) Fischer carbene complexes: a new approach to diarylethanone
Chromium Fischer carbene complexes react with the in situ generated diazo compounds to afford methyl enolate products which are hydrolyzed to give diarylethanones.
Ruthenium complexes with an N-heterocyclic carbene NNC-pincer ligand: preparation and catalytic properties
An NNC NHC-based pincer-type Ru(II) complex was obtained and tested in the reduction of carbonyl groups.
About this collection
Guest Edited by Guy Bertrand (UCSD), Frank Glorius (University of Münster) and F. Ekkehardt Hahn (University of Münster), this themed collection aims to highlight recent advances on the structural, catalytic and organometallic aspect of modern carbene chemistry, with special focus on their applications in organic synthesis.
Topics that will be covered include but aren’t limited to:
• free carbenes as synthetic intermediates in organic reactions
• synthetic use of metal catalyzed decomposition of diazo compounds
• Fischer carbenes in organic synthesis
• transition metal-NHCs complexes in homogeneous catalysis
• design and synthesis of novel carbene ligands
• NHCs as organocatalysts
• carbenes coordinated to metal surfaces
• carbenes in polymer synthesis
• metal carbenes and their reactivity in catalysis