581-80-6Relevant articles and documents
Heterogeneous Pd-catalyzed biphenyl synthesis under moderate conditions in a solid-liquid two-phase system
Mukhopadhyay, Sudip,Ratner, Stanislav,Spernat, Aviram,Qafisheh, Nida,Sasson, Yoel
, p. 297 - 300 (2002)
The coupling of substituted halobenzenes to form biphenyls is effected at moderate temperature (65°C) using a reducing agent such as a formate salt and a base (NaOH) in the presence of a catalytic amount of phase-transfer catalyst and 5% Pd/C catalyst. The reaction conditions can be optimized to give reasonable selectivity, and the competing reduction process is minimized. The roles of temperature, catalyst loading, reducing agents, the base, and the phase-transfer catalyst are discussed. The catalyst can be efficiently recycled. However, an entirely different course of reaction occurs when a mixture of halobenzenes is utilized.
Recyclable Pd2dba3/XPhos/PEG-2000 System for Efficient Borylation of Aryl Chlorides: Practical Access to Aryl Boronates
Cai, Mingzhong,Luo, Chengkai,Xu, Caifeng,Huang, Bin
, p. 1339 - 1346 (2021/12/02)
Pd2dba3/XPhos in poly(ethylene glycol) (PEG-2000) is shown to be a highly stable and efficient catalyst for the borylation of aryl chlorides with bis(pinacolato)diboron. The borylation reaction proceeds smoothly at 110 °C, delivering a wide variety of aryl boronates in good to excellent yields with high functional group tolerance. The crude products were easily isolated via simple extraction of the reaction mixture with cyclohexane. Moreover, both expensive Pd2dba3 and XPhos in PEG-2000 system could be readily recycled and reused more than six times without loss of catalytic efficiency.
Competitive gold/nickel transmetalation
Austen, Brady J. H.,Demchuk, Mitchell J.,Drover, Marcus W.,Nelson, David J.,Zurakowski, Joseph A.
supporting information, p. 68 - 71 (2021/12/29)
Transmetalation is a key method for the construction of element-element bonds. Here, we disclose the reactivity of [NiII(Ar)(I)(diphosphine)] compounds with arylgold(i) transmetalating agents, which is directly relevant to cross-coupling catalysis. Both aryl-for-iodide and unexpected aryl-for-aryl transmetalation are witnessed. Despite the strong driving force expected for Au-I bond formation, aryl scrambling can occur during transmetalation and may complicate the outcomes of attempted catalytic cross-coupling reactions.
Nickel-Catalyzed Electrochemical C(sp3)?C(sp2) Cross-Coupling Reactions of Benzyl Trifluoroborate and Organic Halides**
Luo, Jian,Hu, Bo,Wu, Wenda,Hu, Maowei,Liu, T. Leo
supporting information, p. 6107 - 6116 (2021/02/01)
Reported here is the redox neutral electrochemical C(sp2)?C(sp3) cross-coupling reaction of bench-stable aryl halides or β-bromostyrene (electrophiles) and benzylic trifluoroborates (nucleophiles) using nonprecious, bench-stable NiCl2?glyme/polypyridine catalysts in an undivided cell configuration under ambient conditions. The broad reaction scope and good yields of the Ni-catalyzed electrochemical coupling reactions were confirmed by 50 examples of aryl/β-styrenyl chloride/bromide and benzylic trifluoroborates. Potential applications were demonstrated by electrosynthesis and late-stage functionalization of pharmaceuticals and natural amino acid modification, and three reactions were run on gram-scale in a flow-cell electrolyzer. The electrochemical C?C cross-coupling reactions proceed through an unconventional radical transmetalation mechanism. This method is highly productive and expected to find wide-spread applications in organic synthesis.