Search results for "Crafts"
showing 10 items of 101 documents
Acid Catalysis with Alkane/Water Microdroplets in Ionic Liquids
2021
Ionic liquids are composed of an organic cation and a highly delocalized perfluorinated anion, which remain tight to each other and neutral across the extended liquid framework. Here we show that n-alkanes in millimolar amounts enable a sufficient ion charge separation to release the innate acidity of the ionic liquid and catalyze the industrially relevant alkylation of phenol, after generating homogeneous, self-stabilized, and surfactant-free microdroplets (1–5 μm). This extremely mild and simple protocol circumvents any external additive or potential ionic liquid degradation and can be extended to water, which spontaneously generates microdroplets (ca. 3 μm) and catalyzes Brönsted rather …
Reacciones de Friedel-Crafts enantioselectivas de naftoles, fenoles e hidroxiindoles catalizadas por derivados de alcaloides de la Cinchona
2016
Durante los últimos años, han sido descritos numerosos ejemplos de reacciones enantioselectivas con hidroxiarenos, especialmente usando organocatalizadores bifuncionales. A pesar de ello, la funcionalización asimétrica de hidroxiarenos ha sido menos estudiada si la comparamos con reacciones de Friedel-Crafts con indoles o pirroles. Además, el alcance de la reacción respecto del nucleófilo es limitado en muchos casos. En el capítulo 2.2, se describe una descripción detallada de todos las reacciones de Friedel-Crafts enantioselectivas con hidroxiarenos descritas en la bibliografía. En este contexto, durante la presente tesis hemos descrito el desarrollo de nuevos métodos para la funcionalizac…
ChemInform Abstract: Enantioselective Synthesis of Substituted Indoles Through Zirconium(IV)-Catalyzed Friedel-Crafts Alkylation.
2013
The method allows the introduction of a C-3 side chain bearing a tertiary stereogenic center.
Highly Enantioselective Friedel−Crafts Alkylations of Indoles with Simple Enones Catalyzed by Zirconium(IV)−BINOL Complexes
2007
Complexes of BINOL-based ligands with Zr(OtBu)4 catalyze the Friedel-Crafts alkylation reaction of indoles and pyrrole with nonchelating beta-substituted alpha,beta-enones at room temperature affording the expected products with good yields and ee above 95% in most of the studied examples.
ChemInform Abstract: Enantioselective Synthesis of Tertiary Alcohols Through a Zirconium-Catalyzed Friedel-Crafts Alkylation of Pyrroles with α-Ketoe…
2011
Chiral complexes of 1,1′-bi-2-naphthol-based ligands with zirconium tert-butoxide catalyze the Friedel–Crafts alkylation of pyrroles with α-ketoesters to afford tertiary alcohols in good yields and ee up to 98%. The reaction is also of application to 4,7-dihydroindole to give C2-alkylated indoles after oxidation with p-benzoquinone.
Enantioselective Synthesis of Tertiary Alcohols through a Zirconium-Catalized Friedel-Crafts Alkylation of Pyrroles with alpha-Ketoesters
2011
Chiral complexes of 1,10-bi-2-naphthol-based ligands with zirconium tert-butoxide catalyze the Friedel Crafts alkylation of pyrroles with R-ketoesters to afford tertiary alcohols in good yields and ee up to 98%. The reaction is also of application to 4,7-dihydroindole to give C2-alkylated indoles after oxidation with p-benzoquinone.
ChemInform Abstract: Synthesis of Functionalized Indoles with a Trifluoromethyl-Substituted Stereogenic Tertiary Carbon Atom Through an Enantioselect…
2010
Chiral complexes of BINOL-based ligands with zirconium tert-butoxide catalyze the Friedel-Crafts alkylation reaction of indoles with beta-trifluoromethyl-alpha,beta-unsaturated ketones to give functionalized indoles with an asymmetric tertiary carbon center attached to a trifluoromethyl group. The reaction can be applied to a large number of substituted alpha-trifluoromethyl enones and substituted indoles. The expected products were obtained with good yields and ees of up to 99%.
Nevers (Nièvre). Place Mossé, quai des Mariniers [notice archéologique]
2019
Les sondages archéologiques réalisés sur la place Mossé et à ses abords (quai des Mariniers et Tour Goguin) à Nevers, apportent des connaissances nouvelles sur cette partie du quartier bas des faïenciers.
The special qualities of “thrown” pottery in the cultural and environmental landscape of the Seine area in the 6th and 5th centuries BCE
2021
Sevrey (Saône-et-Loire). 8 rue Georges Brusson [notice archéologique]
2019
La fouille préventive, réalisée au 8 rue Georges Brusson à Sevrey, sur une superficie d’environ 300 m2 apporte de nouveaux éléments concernant la production potière dans ce secteur du Val de Saône. La densité et la qualité des vestiges sont tout à fait remarquables. L’étude est toujours en cours, mais il est d’ores et déjà possible de présenter les grands traits caractéristiques des occupations successives.