Palladium-Catalysed Cross-Coupling of Benzylammonium Salts with Boronic Acids under Mild Conditions
作者:Robert Phipps、Paul Türtscher、Holly Davis
DOI:10.1055/s-0036-1588548
日期:2018.2
pathway for the putative benzyl-Pd(II) intermediate obtained upon oxidative addition and have optimised this to obtain fluorene in good yield. Herein, we give a full account of the development of the palladium-catalysed cross-coupling of benzylammonium salts with boronic acids. A range of benzylamine-derived quaternary ammonium salts can be coupled with boronic acids under relatively mild conditions
The first nickel-catalyzed, magnesium-mediated reductive cross-coupling between benzyl chlorides and arylchlorides or fluorides is reported. A variety of diarylmethanes can be prepared in good to excellent yields in a one-pot manner using easy-to-access mixed PPh3/NHC Ni(II) complexes of Ni(PPh3)(NHC)Br2 (NHC = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, IPr, 1a; 1,3-di-tert-butylimidazol-2-ylidene
cobalt‐catalyzed arylation of benzyl chlorides has been developed in order to form functionalized diarylmethanes. A variety of reactive groups either on the aryl or the benzyl halide was employed. This represents the first cobalt‐catalyzed reductive cross‐coupling which does not require any ligand and pyridine. A reaction pathway is proposed involving a radical benzyl species.
Threefold and chemoselective couplings of triarylbismuths with benzylic chlorides and iodides using palladium catalysis
作者:Maddali L. N. Rao、Ritesh J. Dhanorkar
DOI:10.1039/c3ra46672h
日期:——
This paper describes the palladium-catalyzed studies on threefold coupling of triarylbismuth reagents with benzylic chlorides and iodides. The optimized protocol conditions are operationally simple, delivering threefold coupling of a variety of triarylbismuths in combination with benzylic chlorides and iodides. The two optimized protocols allowed the synthesis of a diverse range of unsymmetrical diarylmethanes in an efficient manner. As part of this study, chemoselective transformation of benzylic chlorides and iodides was also achieved.
A simple cobalt‐catalyzed reductive coupling protocol allowing the synthesis of functionalized diarylmethanes from benzyl mesylate is described. The possibility to directly use the benzyl alcohol as a result of a two‐step reaction is also presented. This method tolerates a variety of functional groups. A benzyl radical is likely involved.