1962-08-9Relevant articles and documents
Zeolite-Encaged Isolated Platinum Ions Enable Heterolytic Dihydrogen Activation and Selective Hydrogenations
Dai, Weili,Deng, Xin,Guan, Naijia,Li, Landong,Liu, Runze,Ma, Ding,Qin, Bin,Qin, Xuetao,Wu, Guangjun
supporting information, p. 20898 - 20906 (2021/12/14)
Understanding the unique behaviors of atomically dispersed catalysts and the origin thereof is a challenging topic. Herein, we demonstrate a facile strategy to encapsulate Ptδ+ species within Y zeolite and reveal the nature of selective hydrogenation over a Pt@Y model catalyst. The unique configuration of Pt@Y, namely atomically dispersed Ptδ+ stabilized by the surrounding oxygen atoms of six-membered rings shared by sodalite cages and supercages, enables the exclusive heterolytic activation of dihydrogen over Ptδ+···O2- units, resembling the well-known classical Lewis pairs. The charged hydrogen species, i.e., H+ and Hδ-, are active reagents for selective hydrogenations, and therefore, the Pt@Y catalyst exhibits remarkable performance in the selective hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols and of nitroarenes to arylamines.
Direct Electrophilic C?H Alkynylation of Unprotected 2-Vinylanilines
Caspers, Lucien D.,Finkbeiner, Peter,Nachtsheim, Boris J.
supporting information, p. 2748 - 2752 (2017/03/08)
Unprotected aromatic amines can be used as directing groups in metal-catalyzed C?H alkynylations of alkenes. By using low amounts of an IrIIIcatalyst in combination with alkynylbenziodoxolones as electrophilic alkyne-transfer reagents, highly desirable 1,3-enynes were isolated in excellent yields of up to 98 % with Z stereoselectivity. A broad substrate scope as well as the high synthetic utility of the 1,3-enynes render this new method an efficient approach for the synthesis of five- and six-membered heterocycles. Further derivatizations of the 1,3-enynes to highly substituted quinolines through AuI- and N-bromosuccinimide-mediated exo-dig cyclizations were demonstrated.
Nickel-catalyzed amination of Aryl chlorides with ammonia or ammonium salts
Green, Rebecca A.,Hartwig, John F.
supporting information, p. 3768 - 3772 (2015/03/18)
The nickel-catalyzed amination of aryl chlorides to form primary arylamines occurs with ammonia or ammonium sulfate and a well-defined single-component nickel(0) precatalyst containing a Josiphos ligand and an η2-bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts. Simple alternative: The title reaction, which results in primary arylamines, is catalyzed by well-defined single-component nickel(0) precatalysts containing a Josiphos ligand and an η2-bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts.
