The Synthesis of α-Azidoesters and Geminal Triazides
作者:Philipp Klahn、Hellmuth Erhardt、Andreas Kotthaus、Stefan F. Kirsch
DOI:10.1002/anie.201402433
日期:2014.7.21
representatives of this novel class of triazide compounds: Despite their high nitrogen content, the geminaltriazides are easy to handle, even when preparative‐scale syntheses are performed. (Caution: These procedures still require protective measures!) The triazides are now broadly available for further studies regarding their properties and reactivity. Furthermore, we show how the method can be used to
Gold imidazolium-based ionic liquids, efficient catalysts for cycloisomerization of γ-acetylenic carboxylic acids
作者:Florentina Neaţu、Vasile I. Pârvulescu、Véronique Michelet、Jean-Pierre Gênet、Alexandre Goguet、Christopher Hardacre
DOI:10.1039/b812580e
日期:——
Ionic liquid stabilized gold(III) chloride is shown to be a very active catalyst in the cyclization of sterically hindered and unhindered acetylenic carboxylic acid substrates even in the absence of a base.
Novel Pd heterogeneous catalysts for cycloisomerisation of acetylenic carboxylic acids
作者:Florentina Neaţu、Loredana Proteşescu、Mihaela Florea、Vasile I. Pârvulescu、Cristian M. Teodorescu、Nicoleta Apostol、Patrick Y. Toullec、Véronique Michelet
DOI:10.1039/c0gc00258e
日期:——
The Pd-TPPTS complex (TPPTS - trisodium salt of 3,3′,3′′-phosphanetriyl benzenesulfonic acid) and PdCl42− salt heterogenised onto Zn2AlNO3 layered double hydroxide (LDH) using an ion-exchange procedure, have been shown to be efficient green catalysts in the cycloisomerisation reaction of acetylenic carboxylic acids to the corresponding 5-membered heterocycles.
A highly active diradical cobalt(<scp>iii</scp>) catalyst for the cycloisomerization of alkynoic acids
作者:Nicolas Leconte、Amaury du Moulinet d'Hardemare、Christian Philouze、Fabrice Thomas
DOI:10.1039/c8cc04459g
日期:——
The first cobalt-catalysed cycloisomerisation of alkynoicacids is reported, thanks to the design of a well-defined diradical cobalt(III) catalyst, in the absence of any additives. The high efficiency, regioselectivity and chemoselectivity are comparable to those of noble metal-based systems. The unique reactivity might be attributed to second coordination sphere effects.
Water-Soluble Gold(I) and Gold(III) Complexes with Sulfonated <i>N</i>-Heterocyclic Carbene Ligands: Synthesis, Characterization, and Application in the Catalytic Cycloisomerization of γ-Alkynoic Acids into Enol-Lactones
作者:Eder Tomás-Mendivil、Patrick Y. Toullec、Javier Borge、Salvador Conejero、Véronique Michelet、Victorio Cadierno
DOI:10.1021/cs4009144
日期:2013.12.6
2-pyridyl, 2-picolyl, and 2-pyridylethyl substituents have been synthesized and employed as precursors for the preparation of novel water-soluble Au(I)- and Au(III)-NHC complexes of general composition [AuCl(NHC)] and [AuCl3(NHC)] (NHC = N-heterocyclic carbene), respectively. These complexes proved to be active, selective, and recyclable catalysts for the intramolecular cyclization of γ-alkynoic acids under