Oh my Gold! Gold atoms stabilise catalytically active palladiumnanoparticles when engaged in an alloy heterogenised on carbon. The increased durability makes the Pd–Au/C catalyst more recyclable than the gold‐free Pd/C catalyst for the Sonogashirareaction.
Development of the Suzuki−Miyaura Cross-Coupling Reaction: Use of Air-Stable Potassium Alkynyltrifluoroborates in Aryl Alkynylations
作者:Gary A. Molander、Bryson W. Katona、Fouzia Machrouhi
DOI:10.1021/jo0262356
日期:2002.11.1
cross-coupling reaction of potassiumalkynyltrifluoroborates with aryl halides or triflates proceeds readily with moderate to excellent yields. The potassiumalkynyltrifluoroborates are air- and moisture-stable crystalline solids that can be stored indefinitely, which will provide an advantage in applications to combinatorial chemistry. The alkynyl cross-coupling reaction can be effected using 9 mol % of PdCl2(dppf)
Alkynes react with organoborons under a CO atmosphere in the presence of a rhodium(I) catalyst to afford mainly 5-aryl-2(5H)-furanones, α,β-unsaturated ketones, and indanones. The product selectivity can be tuned by modifying the reaction conditions.
Rhodium(III)-Catalyzed Redox-Neutral CH Annulation of Arylnitrones and Alkynes for the Synthesis of Indole Derivatives
作者:Zhi Zhou、Guixia Liu、Yan Chen、Xiyan Lu
DOI:10.1002/adsc.201500580
日期:2015.9.14
By using a nitrone as the oxidizingdirectinggroup, a mild, practical and efficient rhodium(III)‐catalyzed CH functionalization for the synthesis of indole derivatives has been developed. This reaction obviates the need for an external oxidant and shows good functional group tolerance. The employment of a sterically hindered Mes group on the carbon center of the nitrone is crucial to produce indoles
Neopentylphosphines as effective ligands in palladium-catalyzed cross-couplings of aryl bromides and chlorides
作者:Lensey L. Hill、Joanna M. Smith、William S. Brown、Lucas R. Moore、Paul Guevera、Emily S. Pair、Jake Porter、Joe Chou、Christopher J. Wolterman、Raluca Craciun、David A. Dixon、Kevin H. Shaughnessy
DOI:10.1016/j.tet.2008.02.037
日期:2008.7
The use of neopentylphosphine ligands in the palladium-catalyzed Suzuki, Sonogashira, Heck, and Hartwig–Buchwald couplings of arylbromides and chlorides are reported. Di-tert-butylneopentylphosphine (DTBNpP) provided highly active catalysts for the coupling of arylbromides at mild temperatures. Trineopentylphosphine, an air-stable trialkylphosphine, gave inactive catalysts at room temperature, but