Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• carbenes available to the chemist [7]. Among them, the cyclic (alkyl)(amino)carbenes (CAACs, E) introduced by Bertrand et al. in 2005 [8] have attracted a great deal of attention, thanks to their remarkable nucleophilic (σ-donating) and electrophilic (π-accepting) properties, which allow them to activate a

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

• Veronica Paradiso,
• Chiara Costabile and
• Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

• heteroatoms, such as thiazol-2-ylidene ligands [10], or those containing one nitrogen substituent, such as the series of cyclic (alkyl) (amino) carbenes (CAACs) introduced by Bertrand et al. [11], are not included in this survey. Review Ruthenium catalysts coordinated with N-aryl, N’-aryl NHCs The first

CAAC Boranes. Synthesis and characterization of cyclic (alkyl) (amino) carbene borane complexes from BF₃ and BH₃

• Julien Monot,
• Louis Fensterbank,
• Max Malacria,
• Emmanuel Lacôte,
• Steven J. Geib and
• Dennis P. Curran

Beilstein J. Org. Chem. 2010, 6, 709–712, doi:10.3762/bjoc.6.82

• 10.3762/bjoc.6.82 Abstract In situ formation of two cyclic (alkyl) (amino) carbenes (CAACs) followed by addition of BF3•Et2O provided the first two examples of CAAC–BF3 complexes: 1-(2,6-diisopropylphenyl)-3,5,5-trimethyl-3-phenylpyrrolidin-2-ylidene trifluoroborane, and 2-(2,6-diisopropylphenyl)-3,3

• formed in situ according to 1H and 11B NMR analysis, but did not survive the workup conditions. These results set the stage for further studies of the chemistry of CAAC boranes. Keywords: borane Lewis acid Lewis base complexes; carbene–borane complexes; cyclic (alkyl) (amino) carbenes; N-heterocyclic

• carbenes. Recently, Bertrand introduced, cyclic (alkyl) (amino) carbenes, or CAACs, as a new class of carbene complex in which the central carbene carbon is stabilized by only one nitrogen atom [20][21][22][23]. Herein we report the synthesis and characterization (including X-ray structures) of two stable