RESUMEN
The first rhodium-catalyzed intermolecular hydroamination of alkynes is presented. Terminal alkynes react efficiently with anilines in the presence of cationic rhodium(I) catalysts under very mild reaction conditions (e.g., base and acid free at room temperature) to yield up to 99% of the corresponding imines. An easy one-pot protocol for the synthesis of secondary amines was developed by combining this alkyne amination reaction with in situ addition of organolithium reagents.
RESUMEN
A new catalytic amination of aromatic olefins with anilines is presented. In a domino reaction, substituted quinoline derivatives are obtained in the presence of cationic rhodium complexes, such as [Rh(cod)2]BF4, and PPh3. Ethylbenzene is formed as a by-product in this new oxidative reaction. The first transition metal catalyzed anti-Markovnikov hydroamination of styrene with anilines occurs as a side reaction. Mechanistic investigations strongly support the regioselective oxidative amination of styrene as the key reaction step.
Asunto(s)
Alquenos/metabolismo , Aminas/metabolismo , Compuestos de Anilina/metabolismo , Quinolinas/síntesis química , Alquenos/química , Aminación , Antimaláricos/síntesis química , Antimaláricos/química , Antimaláricos/metabolismo , Derivados del Benceno/metabolismo , Catálisis , Espectroscopía de Resonancia Magnética , Estructura Molecular , Oxidantes/metabolismo , Quinolinas/química , Quinolinas/metabolismo , Rodio/metabolismo , Estirenos/metabolismoRESUMEN
[reaction: see text] The influence of palladium catalysts and reaction conditions on the selectivity of Heck reactions of aryl bromides with cyclohexene and cyclopentene has been investigated. It is shown that the addition of DMSO as a cosolvent leads to improved selectivities of nonconjugated aryl olefins. On the other hand, high selectivities for conjugated arylcyclopentenes have been obtained with the catalytic system DMA/Na2CO3/Pd2(dba)3 x dba/PCy3.