[(2-mesitylindenyl)dicyclohexyl-phosphine]PdCl2 (2) have been synthesized and fully characterized by NMR and elemental analysis, as well as by X-ray crystallography for 2. A Highly active catalyst system derived from a palladium precatalyst and bulky 2-mesitylindenyl phosphine ligand (1) for the Buchwald–Hartwig amination reaction of arylhalides with primary and secondaryamines has been developed. This method
2-Phenylindenyl phosphineligand can be changed into anionic phosphineligand in situ and utilized in the palladium-catalyzed Buchwald/Hartwig amination reactions in DME, providing good to excellent yields of amination products from aryl chlorides, bromides and iodides. 31P NMR studies show that the resonance for the anionic phosphine appeared between those of the (2-phenylindenyl)-dicyclohexyl phosphonium
可将2-苯基茚基膦配体原位转变为阴离子膦配体,并用于DME中钯催化的Buchwald / Hartwig胺化反应中,从芳基氯化物,溴化物和碘化物得到的胺化产物收率良好。31 P NMR研究表明,阴离子膦的共振出现在(2-苯基茚基)-二环己基phospho盐和(2-苯基茚基)二环己基膦盐之间。计算结果与实验结果一致。
Enhanced Activity of [Ni(NHC)CpCl] Complexes in Arylamination Catalysis
作者:Anthony R. Martin、Yusuke Makida、Sébastien Meiries、Alexandra M. Z. Slawin、Steven P. Nolan
DOI:10.1021/om4004863
日期:2013.11.11
Seven new air- and moisture-stable nickel complexes bearing flexible bulky NHC (N-heterocyclic carbene) ancillary ligands (NHC = IPr*, IPrTol*, IPrOMe*, IPent) are reported. Using experimentally determined crystal structures, the steric environments of [Ni(NHC)CpCl] complexes were analyzed. A survey of their catalytic activity in Buchwald-Hartwig arylamination has been performed. In comparison to less sterically demanding analogues (NHC = IMes, SIMes, IPr, SIPr), an increase in the ligand bulkiness was found to correlate to a dramatic enhancement of the C-N bond formation efficiency. Finally, the catalytic activity of the most active precatalyst, [Ni(IPrOMe*)CpCl], was further explored and the scope and limitations of this complex were examined.
Photocatalytic Hydrogen-Evolving Cross-Coupling of Arenes with Primary Amines
Herein, we described a cooperative catalyst system consisting of an acridinium photoredox catalyst and a cobalt-based proton-reduction catalyst that is effective for the C-H amination of arenes with concomitant generation of hydrogen. This oxidant free method allows a variety of amines with diverse functional groups to be converted to aromatic amines. Additionally, this protocol can also be extended to hydrolytically unstable benzophenone imines.
[EN] COLORED CURABLE RESIN COMPOSITION<br/>[FR] COMPOSITION DE RÉSINE DURCISSABLE COLORÉE