2290-40-6Relevant articles and documents
Nickel-Catalyzed Defluorinative Coupling of Aliphatic Aldehydes with Trifluoromethyl Alkenes
Montgomery, John,Xiao, Jichao
, p. 2463 - 2471 (2022/02/17)
A simple procedure is reported for the nickel-catalyzed defluorinative alkylation of unactivated aliphatic aldehydes. The process involves the catalytic reductive union of trifluoromethyl alkenes with aldehydes using a nickel complex of a 6,6′-disubstituted bipyridine ligand with zinc metal as the terminal reductant. The protocol is distinguished by its broad substrate scope, mild conditions, and simple catalytic setup. Reaction outcomes are consistent with the intermediacy of an α-silyloxy(alkyl)nickel intermediate generated by a low-valent nickel catalyst, a silyl electrophile, and the aldehyde substrate. Mechanistic findings with cyclopropanecarboxaldehyde provide insights into the nature of the reactive intermediates and illustrate fundamental reactivity differences that are governed by subtle changes in the ligand and substrate structure.
Nickel-catalyzed reductive coupling of unactivated alkyl bromides and aliphatic aldehydes
Cruz, Cole L.,Montgomery, John
, p. 11995 - 12000 (2021/09/28)
A mild, convenient coupling of aliphatic aldehydes and unactivated alkyl bromides has been developed. The catalytic system features the use of a common Ni(ii) precatalyst and a readily available bioxazoline ligand and affords silyl-protected secondary alcohols. The reaction is operationally simple, utilizing Mn as a stoichiometric reductant, and tolerates a wide range of functional groups. The use of 1,5-hexadiene as an additive is an important reaction parameter that provides significant benefits in yield optimizations. Initial mechanistic experiments support a mechanism featuring an alpha-silyloxy Ni species that undergoes formal oxidative addition to the alkyl bromideviaa reductive cross-coupling pathway.
Pd catalysts supported on dual-pore monolithic silica beads for chemoselective hydrogenation under batch and flow reaction conditions
Yamada, Tsuyoshi,Ogawa, Aya,Masuda, Hayato,Teranishi, Wataru,Fujii, Akiko,Park, Kwihwan,Ashikari, Yosuke,Tomiyasu, Noriyuki,Ichikawa, Tomohiro,Miyamoto, Riichi,Bai, Hongzhi,Matsuyama, Kiyoshi,Nagaki, Aiichiro,Sajiki, Hironao
, p. 6359 - 6367 (2020/11/03)
Two different types of palladium catalysts supported on dual-pore monolithic silica beads [5% Pd/SM and 0.25% Pd/SM(sc)] for chemoselective hydrogenation were developed. Alkyne, alkene, azide, and nitro functionalities and the aromatic N-Cbz protecting group were chemoselectively hydrogenated using 5% Pd/SM. On the other hand, 0.25% Pd/SM(sc) showed unique and higher hydrogenation catalyst activity toward a wide variety of reducible functionalities. Furthermore, the catalyst activities of both 5% Pd/SM and 0.25% Pd/SM(sc) under flow hydrogenation conditions were also evaluated. A pre-packed 5% Pd/SM cartridge could be used continuously for at least 72 h without any loss of catalyst activity. The 0.2% Pd/SM(sc) catalyst prepacked in a cartridge showed high catalyst activity for the flow hydrogenation of trisubstituted alkenes under mild reaction conditions. This journal is
