61270-28-8Relevant articles and documents
Amphipathic monolith-supported palladium catalysts for chemoselective hydrogenation and cross-coupling reactions
Monguchi, Yasunari,Wakayama, Fumika,Ueda, Shun,Ito, Ryo,Takada, Hitoshi,Inoue, Hiroshi,Nakamura, Akira,Sawama, Yoshinari,Sajiki, Hironao
, p. 1833 - 1840 (2017/01/21)
A palladium catalyst immobilized on an amphipathic and monolithic polystyrene-divinylbenzene polymer bearing strongly acidic cation exchange functions (sulfonic acid moieties) (Pd/CM) was developed. It was used as a catalyst for hydrogenation and ligand-free cross-coupling reactions, such as the Suzuki-Miyaura, Mizoroki-Heck, and copper- and amine-free Sonogashira-type reactions, together with a palladium catalyst supported on monolithic polymer (Pd/AM) bearing basic anion exchange functions (ammonium salt moieties), which has been in practical use for the decomposition of hydrogen peroxide produced as a byproduct during the manufacture of ultrapure water. While the Pd/CM was highly active as a catalyst for the hydrogenation and a variety of reducible functional groups could be reduced, the use of Pd/AM led to a unique chemoselective hydrogenation. Aromatic carbonyl groups were tolerant under the Pd/AM-catalyzed hydrogenation conditions, although benzyl esters, benzyl ethers, and N-Cbz groups could be smoothly hydrocracked. The cross-coupling reactions readily proceeded using either catalyst. The palladium leaching from the Pd/CM into the reaction media was never observed during the Sonogashira-type reaction, which was hardly achieved by other palladium-supported heterogeneous catalysts due to the good affinity of the palladium species with alkynes.
Chemoselective hydrogenation catalyzed by Pd on spherical carbon
Esaki, Hiroyoshi,Hattori, Tomohiro,Tsubone, Aya,Mibayashi, Satoko,Sakata, Takao,Sawama, Yoshinari,Monguchi, Yasunari,Yasuda, Hidehiro,Nosaka, Kazuto,Sajiki, Hironao
, p. 3629 - 3635 (2014/01/06)
We have developed a highly chemoselective hydrogenation method using a novel palladium catalyst supported on spherical carbon (0.5 % Pd/SC). The 0.5 % Pd/SC exhibited a novel catalytic activity and could achieve the chemoselective hydrogenation of alkynes, alkenes, azides, nitro groups, and aliphatic O-tert-butyldimethylsilyl (TBS) ethers without hydrogenolysis of benzyl esters, benzyl ethers, nitriles, aromatic ketones, N-carbobenzyloxy (N-Cbz) protective groups, and aromatic O-TBS ethers. Highly selective spheres: The chemoselective hydrogenation of C-C multiple bonds, azides, nitro groups, and aliphatic O-tert-butyldimethylsilyl (TBS) ethers is achieved in the presence of benzyl esters, benzyl ethers, nitriles, aromatic ketones, N-carbobenzyloxy (Cbz) protective groups, and aromatic O-TBS ethers by a novel heterogeneous palladium catalyst supported on spherical carbon (0.5 % Pd/SC). Copyright
Safe, convenient ortho-Claisen thermal rearrangement using a flow reactor
Rincon, Juan A.,Barberis, Mario,Gonzalez-Esguevillas, Maria,Johnson, Martin D.,Niemeier, Jeffry K.,Sun, Wei-Ming
scheme or table, p. 1428 - 1432 (2012/01/11)
The [3,3] Claisen rearrangement is a well-known reaction that has been very useful for the synthesis of o-allyl phenols. The thermally induced rearrangement could present safety and operational issues at large batch scale. Herein, we report a process that