<i>N</i>-Heterocyclic Carbene Coordinated Heterogeneous Pd Nanoparticles as Catalysts for Suzuki–Miyaura Coupling
作者:Hyemin Min、Hiroyuki Miyamura、Shū Kobayashi
DOI:10.1246/cl.160369
日期:2016.7.5
Palladium nanoparticle (Pd NP) catalysts immobilized in a polymer with an N-heterocycliccarbene (NHC) moiety (PICB-NHC-Pd) have been developed, wherein the NHC moiety plays dual roles as a crosslinker and a ligand to activate the Pd NPs. The presence of both Pd NPs and NHC was confirmed by STEM/EDS and SR-MAS NMR analyses, respectively. This PICB-NHC-Pd catalyst showed excellent activity in the Suzuki–Miyaura
Synthesis of Aryl Trimethylstannanes from Aryl Amines: A Sandmeyer-Type Stannylation Reaction
作者:Di Qiu、He Meng、Liang Jin、Shuai Wang、Shengbo Tang、Xi Wang、Fanyang Mo、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201304579
日期:2013.10.25
Sandmeyer‐type stannylation: Stille coupling is one of the most powerful coupling reactions for CC bond formation, whereas there are only limited methods to access aryl stannane compounds. A mild stannylation process based on a Sandmeyer‐type transformation using aromatic amines as the starting materials is described. DCE: 1,2‐dichloroethane.
Aromatic substitution. Part XXII. Polarity of aryl radicals
作者:R. A. Abramovitch、O. A. Koleoso
DOI:10.1039/j29690000779
日期:——
The rates of substitution of anisole relative to benzene by arylradicals generated from diazonium tetrafluoroborates and pyridine in homogeneous solution have been measured and follow, qualitatively, the order expected on the basis of the theory of polarised arylradicals. The substituent in the radical affects its permanent polarisation. Apparent contradictions in the literature concerning the behaviour
已经测量了在均匀溶液中苯甲醚相对于苯的取代度,该取代度是由四氟硼酸重氮鎓和吡啶生成的芳基产生的,并且定性地遵循了基于极化芳基自由基理论的预期顺序。自由基中的取代基会影响其永久极化。文献中有关苯甲醚作为底物的行为和对甲氧基苯基自由基的极性的明显矛盾通过使用这种自由基源得以解决。如所预期的,对甲氧基苯基比苯基更具亲核性。间甲氧基苯基不比苯基更具亲电性,并提出了一个解释。p甲苯基是多个亲核比预期的基础上σ p -Me。
Iridium Catalysis for CH Bond Arylation of Heteroarenes with Iodoarenes
作者:Benoît Join、Takuya Yamamoto、Kenichiro Itami
DOI:10.1002/anie.200806358
日期:2009.5.4
Efficient couplings using equimolar quantities of each coupling partner and multiple CHbondarylation reactions are achieved with an Ir‐based catalytic system for the CHbondarylation of electron‐rich heteroarenes with iodoarenes to construct extended π‐systems. The dramatic ligand effect on reaction efficiency leads to the discovery that Crabtree's catalyst (see scheme) is the optimal catalyst