An Amphiphilic Resin-dispersion of Nanoparticles of Platinum (ARP-Pt): A Highly Active and Recyclable Catalyst for the Aerobic Oxidation of a Variety of Alcohols in Water
作者:Yoichi M. A. Yamada、Takayasu Arakawa、Heiko Hocke、Yasuhiro Uozumi
DOI:10.1002/asia.200800478
日期:2009.7.6
Please recycle! An amphiphilic polystyrene‐poly(ethylene glycol) resin‐dispersion of nanoparticles of platinum (ARP‐Pt) is developed, with the nanoparticles exhibiting a narrow size distribution throughout the resin. ARP‐Pt offers a sustainable chemistry alternative as a useful and readily recyclable catalyst for the aerobicoxidation of a wide variety of alcohols.
Vinyl Azides as Radical Acceptors in the Vitamin B<sub>12</sub>-Catalyzed Synthesis of Unsymmetrical Ketones
作者:Krzysztof R. Dworakowski、Sabina Pisarek、Sidra Hassan、Dorota Gryko
DOI:10.1021/acs.orglett.1c03321
日期:2021.12.3
Vinyl azides are very reactive species and as such are useful building blocks, in particular, in the synthesis of N-heterocycles. They can also serve as precursors of ketones. These form in reactions of vinyl azides with nucleophiles or radicals. We have found, however, that under light irradiation vitamin B12 catalyzes the reaction of vinyl azides with electrophiles to afford unsymmetrical carbonyl
乙烯基叠氮化物是非常活泼的物质,因此是有用的结构单元,特别是在N-杂环的合成中。它们还可以作为酮的前体。这些是在乙烯基叠氮化物与亲核试剂或自由基的反应中形成的。然而,我们发现,在光照射下,维生素 B 12催化乙烯基叠氮化物与亲电子试剂的反应,以良好的产率提供不对称羰基化合物。机理研究表明烷基自由基是这种转变的关键中间体。
Alkyl Ethers as Traceless Hydride Donors in Brønsted Acid Catalyzed Intramolecular Hydrogen Atom Transfer
A new protocol for the deoxygenation of alcohols and the hydrogenation of alkenes under Brønsted acid catalysis has been developed. The method is based on the use of either a benzyl or isopropyl ether as a tracelesshydrogen‐atom donor, and involves an intramolecular hydride transfer as a key step, which is achieved in a regio‐ and stereoselective manner.