Reductive amination of various ketones and aldehydes by transferhydrogenation under aqueous conditions has been developed, by using cyclometallated iridium complexes as catalysts and formate as hydrogen source. The pH value of the solution is shown to be critical for a high catalytic chemoselectivity and activity, with the best pH value being 4.8. In comparison with that in organic solvents, the reductive
A new [2.2]paracyclophane-based electron-rich and sterically bulky monophosphine ligand has been synthesized by an efficient and straightforward method. When combined with palladium, this ligand shows excellent performance in the Buchwald–Hartwig amination and Suzuki–Miyaura coupling reactions of various aryl chlorides. In both types of reactions, ortho-substituted, deactivated aryl chlorides are shown to be viable substrates. However, the Suzuki–Miyaura coupling appears to be easier, with palladium loading at 0.1 mol% being feasible.
Boron-Catalyzed <i>N</i>-Alkylation of Arylamines and Arylamides with Benzylic Alcohols
作者:Murali Mohan Guru、Pradip Ramdas Thorve、Biplab Maji
DOI:10.1021/acs.joc.9b02816
日期:2020.1.17
A sustainable boron-based catalytic approach for chemoselective N-alkylation of primary and secondary aromatic amines and amides with primary, secondary, and tertiary benzylic alcohols has been presented. The metal-free protocol operates at low catalyst loading, tolerates several functional groups, and generates H2O as the sole byproduct. Preliminary mechanistic studies were performed to demonstrate
A Tetraarylpyrrole‐Based Phosphine Ligand for the Palladium‐Catalyzed Amination of Aryl Chlorides
作者:Masahiro Sai
DOI:10.1002/adsc.202100731
日期:2021.12.21
A tetraarylpyrrole-based phosphine ligand L1 in combination with Pd(dba)2 provided a catalyst for the Buchwald-Hartwig amination reaction. A variety of amines were rapidly coupled with aryl chlorides at a Pd loading of 0.5 mol%. The selective monoarylation of aliphatic primary amines was achieved in the presence of 0.8 equiv. water. Comparison experiments were also conducted, which revealed that the
Titanium hydroamination catalysts bearing a 2-aminopyrrolinato spectator ligand: monitoring the individual reaction steps
作者:Katharina Weitershaus、Benjamin D. Ward、Raphael Kubiak、Carsten Müller、Hubert Wadepohl、Sven Doye、Lutz H. Gade
DOI:10.1039/b902038a
日期:——
ligand N(Xyl)N}(-) as the ancillary ligand, have been prepared and are shown to be pre-catalysts for the hydroamination of alkynes. The coordination of N(Xyl)N}(-) to titanium was achieved by reaction of [Cp*TiMe(3)] with the protioligand N(Xyl)NH giving [Cp*Ti(N(Xyl)N)(Me)(2)] (). Upon reaction of complex with an excess of tert-butylamine, the imido complex [Cp*Ti(N(Xyl)N)(N(t)Bu)(NH(2)(t)Bu)] () was