101-23-5Relevant articles and documents
Facile synthesis of Fe@Pd nanowires and their catalytic activity in ligand-free CN bond formation in water
Nasrollahzadeh, Mahmoud,Azarian, Abbas,Ehsani, Ali,Zahraei, Ali
, p. 2813 - 2817 (2014)
This work reports a facile synthesis of Fe@Pd nanowires. Ligand-free cross coupling reactions of arylboronic acids with various amines in aqueous medium proceed in very good to excellent yield with the use of Fe@Pd nanowires. Furthermore, the catalyst could be easily separated from the reaction mixture using a magnet and could be recycled several times without loss of catalytic activity.
Chan-Evans-Lam C?N Coupling Promoted by a Dinuclear Positively Charged Cu(II) Complex. Catalytic Performance and Some Evidence for the Mechanism of CEL Reaction Obviating Cu(III)/Cu(I) Catalytic Cycle
Akatyev, Nikolay,Il'in, Mikhail,Il'in, Mikhail,Peregudova, Svetlana,Peregudov, Alexander,Buyanovskaya, Anastasiya,Kudryavtsev, Kirill,Dubovik, Alexander,Grinberg, Valerij,Orlov, Victor,Pavlov, Alexander,Novikov, Valentin,Volkov, Ilya,Belokon, Yuri
, p. 3010 - 3021 (2020/04/29)
In the present study, we report the synthesis of a series of copper(II) complexes with a wide range of ligands and their testing in the copper catalyzed Chan-Evans-Lam (CEL) coupling of aniline and phenylboronic acid. The efficiency of the coupling was directly connected with the ease of the reduction of Cu(II) to Cu(I) of the complexes. The most efficient catalyst was derived from 4-t-butyl-2,5-bis[(quinolinylimino)methyl]phenolate and two Cu(II) ions. Depending on the counter-anion nature and the concentration of the reaction mixture, the reaction can be directed to predominant C?N-bond formation. Forty-three derivatives of diphenylamine were prepared under the optimized conditions. The proposed mechanism of the catalysis was based on the reduction potential of a series of complexes, molecular weight measurements of the catalytic complex in MeOH and the kinetic studies of aniline and phenylboronic acid coupling. In addition, an 1H NMR experiment in a sealed NMR tube, without external oxygen supply available, proved that no complete Cu(II) to Cu(I) conversion was observed under the condition, ruling out the usually accepted mechanism of the C?N coupling, which included the oxygenation of the intermediately formed Cu(I) complexes after the key step of C?N conversion had already been completed. Instead, a mechanism was proposed, involving an oxygen molecule coordinated to two copper ions in the key C?N bond formation without any detectable conversion of the Cu(II) complexes to Cu(I).
Copper-catalyzed, ceric ammonium nitrate mediated N-arylation of amines
Gonela, Uma Maheshwar,Ablordeppey, Seth Y.
supporting information, p. 2861 - 2864 (2019/02/17)
Cu-Catalyzed, ligand- and base-free cross-coupling of aryl boronic acids with primary and secondary amines has been reported. This ‘Chan-Evans-Lam' reaction has revealed that at room temperature, with a catalytic amount of copper(ii) acetate and ceric ammonium nitrate (CAN) as an oxidant, N-arylation can result in an effective C-N bond formation. This air stable, practical, robust protocol enables tolerance towards a variety of functional groups on both boronic acid and amine partners.
NIXANTPHOS: A highly active ligand for palladium catalyzed Buchwald-Hartwig amination of unactivated aryl chlorides
Mao, Jianyou,Zhang, Jiadi,Zhang, Shuguang,Walsh, Patrick J.
supporting information, p. 8690 - 8696 (2018/07/13)
Xantphos is one of the two most common ligands used in palladium catalyzed Buchwald-Hartwig amination reactions, because of its broad scope and high probability of success. It does not, however, work well with unactivated aryl chlorides. Herein NIXANTPHOS is compared to Xantphos and an array of mono- and bidentate phosphines. NIXANTPHOS outperforms Xantphos and all other bidentate ligands examined. Under the optimal reaction conditions, unactivated aryl chlorides afford the expected products in good to excellent yield with as low as 0.05 mol% (500 ppm) palladium loading.
