Search results for " metal catalysis"
showing 5 items of 5 documents
Phosphine Ligands Based on the Ferrocenyl Platform: Advances in Catalytic Cross-Couplings
2023
Ferrocenyl skeletons tagged with a variety of donor atoms (metalloligands) have become popular in modern metal-catalyzed organic transformations, broadening the applications. Ferrocenylphosphines, such as 1′-bis(diphenylphosphino)ferrocene (dppf), have been widely used as metalloligands in academic and industrial research, motivating further investigation into novel ferrocenylphosphine ligands. The current review concentrated non-exhaustively on emblematic applications of different ferrocenylphosphine ligands in transition metal-catalyzed cross-coupling strategies. Initially, the stereochemical aspects of the ferrocenyl skeleton, nomenclature, and applications of chiral ferrocenyl phosphine…
Radical addition to iminium ions and cationic heterocycles
2014
Carbon-centered radicals represent highly useful reactive intermediates in organic synthesis. Their nucleophilic character is reflected by fast additions to electron deficient C=X double bonds as present in iminium ions or cationic heterocycles. This review covers diverse reactions of preformed or in situ-generated cationic substrates with various types of C-radicals, including alkyl, alkoxyalkyl, trifluoromethyl, aryl, acyl, carbamoyl, and alkoxycarbonyl species. Despite its high reactivity, the strong interaction of the radical’s SOMO with the LUMO of the cation frequently results in a high regioselectivity. Intra- and intermolecular processes such as the Minisci reaction, the Porta react…
Reactivity of phenylhydrazones in ionic liquids solution: the effect of copper(II) salts
Cross-Linked Thiazolidine Network as Support for Palladium: A New Catalyst for Suzuki and Heck Reactions
2015
A thiazolidine-based material was used for the first time as support for palladium. The support was prepared by starting from a highly cross-linked thiazolium-based material, obtained by radical oligomerization of a bisvinylthiazolium dibromide salt in the presence of 3-mercaptopropyl-modified silica SBA-15. Palladium was immobilized by treatment with tetrachloropalladate salt. Reduction with sodium borohydride afforded a thiazolidine-based material that acted as ligands for the Pd species. The thiazolidine-based palladium catalyst was fully characterized and, working in only 0.1 mol% amount, displayed good activity in the Suzuki-Miyaura and in the Heck reactions. Several biphenyl and alken…
New methodologies in transition metal catalysis. Organofluorine chemistry as the benchmark application.
2017
A lo largo de las últimas décadas, los compuestos organofluorados han encontrado numerosas aplicaciones dentro del campo de las industrias farmacéutica y agroquímica, así como en ciencias de los materiales. Dadas las singulares propiedades del átomo de flúor, éste es capaz de inducir alteraciones significativas en propiedades físico-químicas de las moléculas como lipofilia, distribución de cargas, acidez-basicidad, capacidad de formar enlaces de hidrógeno e incluso, equilibrios conformacionales. Sin embargo, la presencia de flúor en productos naturales es escasa. De hecho, la gran mayoría de las moléculas orgánicas que contienen flúor son sintéticas. De ahí el gran interés por parte de la c…