54960-99-5Relevant academic research and scientific papers
Palladium Complexes Based on Ylide-Functionalized Phosphines (YPhos): Broadly Applicable High-Performance Precatalysts for the Amination of Aryl Halides at Room Temperature
Tappen, Jens,Rodstein, Ilja,McGuire, Katie,Gro?johann, Angela,L?ffler, Julian,Scherpf, Thorsten,Gessner, Viktoria H.
, p. 4281 - 4288 (2020)
Palladium allyl, cinnamyl, and indenyl complexes with the ylide-substituted phosphines Cy3P+?C?(R)PCy2 (with R=Me (L1) or Ph (L2)) and Cy3P+?C?(Me)PtBu2 (L3) were prepared and applied as defined precatalysts in C?N coupling reactions. The complexes are highly active in the amination of 4-chlorotoluene with a series of different amines. Higher yields were observed with the precatalysts in comparison to the in situ generated catalysts. Changes in the ligand structures allowed for improved selectivities by shutting down β-hydride elimination or diarylation reactions. Particularly, the complexes based on L2 (joYPhos) revealed to be universal precatalysts for various amines and aryl halides. Full conversions to the desired products are reached mostly within 1 h reaction time at room temperature, thus making L2 to one of the most efficient ligands in C?N coupling reactions. The applicability of the catalysts was demonstrated for aryl chlorides, bromides and iodides together with primary and secondary aryl and alkyl amines, including gram-scale applications also with low catalyst loadings of down to 0.05 mol %. Kinetic studies further demonstrated the outstanding activity of the precatalysts with TOF over 10.000 h?1.
Iodine-Mediated Coupling of Cyclic Amines with Sulfonyl Hydrazides: an Efficient Synthesis of Vinyl Sulfone Derivatives
Rong, Xiaona,Guo, Jingwen,Hu, Zheqi,Huang, Lehao,Gu, Yugui,Cai, Yuepiao,Liang, Guang,Xia, Qinqin
supporting information, p. 701 - 708 (2020/12/30)
An efficient iodine-mediated coupling of cyclic amines with sulfonyl hydrazides is reported. This transformation opens a new route to the synthesis of vinyl sulfones derivatives, which is a common structural motif in natural products and pharmaceuticals. Tentative mechanistic studies suggest that this reaction is likely to involve a radical process.
2,6-diisopropoxyphenyl(dicyclohexyl)phosphine: A new ligand for palladium-catalyzed amination reactions of aryl chlorides with potassium hydroxide as the base
Lue, Bo,Li, Pengbin,Fu, Chunling,Xue, Liqin,Lin, Zhenyang,Ma, Shengming
experimental part, p. 100 - 112 (2011/04/12)
A new, readily available monophosphine tetrafluoroborate salt [L2·HBF4] was developed for the palladium-catalyzed amination reaction of aryl chlorides in moderate to high yields with the cheap and easily available potassium hydroxide as the base. The reaction enjoys a wide scope, lower reaction temperatures, shorter reaction times, high yields, and low catalyst loading when compared to some of same amination reactions reported in the literature. Based on a kinetic study, 31P NMR measurements, and DFT calculations, a mechanism involving a 1:1 Pd/L species is proposed.
A multiligand based Pd catalyst for C-N cross-coupling reactions
Fors, Brett P.,Buchwald, Stephen L.
supporting information; experimental part, p. 15914 - 15917 (2011/01/07)
An alternative approach to catalyst development, which led to a Pd catalyst based on two biarylphosphine ligands for C-N cross-coupling reactions, is reported. By effectively being able to take the form of multiple catalysts this system manifests the best properties that catalysts based on either of the two ligands exhibit separately and displays the highest reactivity and substrate scope of any system that has been reported to date for these reactions.
