Palladium Nanoparticles on Graphite Oxide as Catalyst for SuzukiMiyaura, MizorokiHeck, and Sonogashira Reactions
作者:Luigi Rumi、Gil M. Scheuermann、Rolf Mülhaupt、Willi Bannwarth
DOI:10.1002/hlca.201000412
日期:2011.6
system was applied successfully to SuzukiMiyaura couplings of some arylchlorides and to the MizorokiHeck as well as the Sonogashira reaction showing relatively high activities and good selectivities. Like with other ligand‐free supported systems, the reaction proceeded dominantly by a homogeneousmechanism, but attack of an aryl iodide to Pd‐nanoparticles can be excluded as substantial contribution
limitations of the base-free oxidativeHeckreaction with arylboronicacids have been explored. Under our conditions, the dmphen−palladium(II)-catalyzed arylation proceeded with air or p-benzoquinone as reoxidants of palladium(0). We found that ambient temperature and mild aerobic conditions allow for the use of substrates sensitive to palladium(II)-catalyzedoxidation. OxidativeHeck couplings, employing
Bipyridine-Modulated Palladium-Catalyzed Oxidative Heck-Type Reactions of Arylboronic Acids with Olefins
作者:Chien-Ming Hsu、Chih-Bin Li、Chia-Hsing Sun
DOI:10.1002/jccs.200900129
日期:2009.10
We have demonstrated that 4,4′‐dimethyl 2,2′‐bipyridine as ligand for Pd(II) catalysts was very efficient for oxidativeHeck‐type coupling reaction of arylboronicacids with olefins in DMA or CH3CN under atm air at 80 °C. The presence of chelated bipyridine ligand isindispensable to achieve high reaction yields and to suppress the formation of biphenyl as homocoupled byproduct.