1591-31-7Relevant articles and documents
Organocatalysis in cross-coupling: DMEDA-catalyzed direct C-H arylation of unactivated benzene
Liu, Wei,Cao, Hao,Zhang, Hua,Zhang, Heng,Chung, Kin Ho,He, Chuan,Wang, Haibo,Kwong, Fuk Yee,Lei, Aiwen
, p. 16737 - 16740 (2010)
A striking breakthrough to the frame of traditional cross-couplings/C-H functionalizations using an organocatalyst remains unprecedented. We uncovered a conceptually different approach toward the biaryl syntheses by using DMEDA as the catalyst to promote the direct C-H arylation of unactivated benzene in the presence of potassium tert-butoxide. The arylation of unactivated benzene with aryl iodides, or aryl bromides and even chlorides under the assistance of an iodo-group, could simply take place at 80 °C. The new methodology presumably involves an aryl radical anion as an intermediate. This finding offers an option toward establishing a new horizon for direct C-H/cross-coupling reactions.
A novel three-step synthesis of N-(2-ethylhexyl)-2,7-diiodocarbazole
Vyprachticky, Drahomir,Kminek, Ivan,Pavlakova, Petra,Cimrova, Vera
, p. 1472 - 1476 (2011)
A new short and reasonably efficient synthesis of N-(2-ethylhexyl)-2,7- diiodocarbazole is presented. 4,4-Diiodobiphenyl was nitrated and the resulting 4,4-diiodo-2-nitrobiphenyl was converted via Freeman's modification of the Cadogan ring closure into 2,7-diiodocarbazole, which was then alkylated in the final step. The synthesis represents a significant simplification of the reported five-step procedure.
Dual gold photoredox C(sp2)-C(sp2) cross couplings-development and mechanistic studies
Gauchot, Vincent,Lee, Ai-Lan
, p. 10163 - 10166 (2016)
A dual visible light photoredox and gold-catalysed C(sp2)-C(sp2) cross coupling is described. The success of this mild, oxidant- and base-free cross coupling is highly dependent on the amount of water added. Mechanistic studies show two distinct pathways depending on the gold catalyst employed: transmetallation of the arylboronic acid with gold(i) occurs prior to oxidation of gold(i) to gold(iii) using cationic gold(i) catalysts, whereas oxidation of gold(i) to gold(iii) precedes transmetallation using neutral gold(i) catalysts.
Suzuki-Miyaura cross-coupling of arenediazonium salts with arylboronic acids catalyzed by a recyclable polymer-supported N-heterocyclic carbene-palladium catalyst
Qin, Yuancheng,Wei, Wei,Luo, Meiming
, p. 2410 - 2414 (2007)
The Suzuki-Miyaura cross-coupling of arenediazonium salts with arylboronic acids catalyzed by a recyclable polymer-supported N-heterocyclic carbene-Pd complex catalyst has been achieved for the first time. The reaction was performed at room temperature under aerobic conditions to give biaryls in good to excellent yields in the absence of a base. The supported catalyst could be reused several times and still retained its high activity. Georg Thieme Verlag Stuttgart.
Halogen Exchange Between Aryl Grignarg Reagents and Aryl Halides in the Presence of Nickel(II) Chloride
Wang, Jiping,Pomerantz, Martin
, p. 2571 - 2574 (1995)
A unique halogen exchange reaction between aryl Grignard reagents and aryl halides, which occured during an attempted cross-coupling reaction using non-ligated nickel(II) chloride as a catalyst, has been observed.The halogen exchange takes place between arylmagnesium iodides and aryl bromides but not between arylmagnesium bromides and aryl chlorides.
Biaryl Coupling of Aryldiazonium Salts and Arylboronic Acids Catalysed by Gold
Medina-Mercado, Ignacio,Porcel, Susana
, (2022/03/15)
A gold-catalysed coupling of aryldiazonium salts with arylboronic acids is described. The reactions proceed in satisfactory yields under irradiation with blue LEDs in the presence of KF and a catalytic amount of ascorbic acid. Notably, 4-nitrobenzendiazonium tetrafluoroborate is sufficiently reactive to undergo the coupling with a variety of arylboronic acids in the absence of aryl radical initiators. The coupling is applicable for electron-donating and electron-withdrawing groups present at the para, ortho, and meta positions of both substrates.
Hydrogen-Bond-Donor Solvents Enable Catalyst-Free (Radio)-Halogenation and Deuteration of Organoborons
Yang, Yi,Gao, Xinyan,Zeng, Xiaojun,Han, Junbin,Xu, Bo
supporting information, p. 1297 - 1300 (2020/12/23)
A hydrogen bond donor solvent assisted (radio)halogenation and deuteration of organoborons has been developed. The reactions exhibited high functional group tolerance and needed only an ambient atmosphere. Most importantly, compared to literature methods, our conditions are more consistent with the principals of green chemistry (e.g., metal-free, strong oxidant-free, more straightforward conditions).
Synthesis of biaryl compounds via Suzuki homocoupling reactions catalyzed by metal organic frameworks encapsulated with palladium nanoparticles
Bao, Yan-Sai,Cui, Xin-Yu,Han, Zheng-Bo,Li, Xin,Tang, Hong,Yang, Ming,Zhang, Yu-Yang,Zhao, Kun,Zhou, Mei-Li
, (2020/12/17)
Heterogeneous homocoupling reactions of phenylboronic acids were greatly accelerated via Suzuki homocoupling reactions. In this work, a tandem route was designed which firstly one part of phenylboronic acids reacted with iodine to form iodobenzenes, then another part of phenylboronic acids coupled with iodobenzenes to produce biaryl compounds. The tandem reaction were catalyzed by a bifunctional heterogeneous catalyst of metal organic frameworks encapsulated with palladium nanoparticles (Pd?MOFs). This strategy for forming symmetric C-C bond between benzene rings has obvious advantages such as high efficiency, easy separation, good recyclability and no addition of toxic halogenated benzene.
