19617-68-6Relevant articles and documents
New Nickel-Based Catalytic System with Pincer Pyrrole-Functionalized N-Heterocyclic Carbene as Ligand for Suzuki-Miyaura Cross-Coupling Reactions
Guo, Zhifo,Lei, Xiangyang
supporting information, (2021/09/11)
A new catalytic system with Ni(NO3)2·6H2O as the catalyst and a pincer pyrrole-functionalized N-heterocyclic carbene as the ligand was employed in the Suzuki-Miyaura cross-coupling reactions of aryl iodides with arylboronic acids. With 5 mol% catalyst, the catalytic reactions proceeded at 160 °C, giving coupling products in isolated yields of up to 94% in short reaction times (1-4 h). The system worked efficiently with aryl iodides bearing electron-donating or electron-withdrawing groups and arylboronic acids with electron-donating groups. Steric effects were observed for both aryl iodides and arylboronic acids. It is proposed that the reactions underwent a Ni(I)/Ni(III) catalytic cycle.
Palladium-catalysed room-temperature Suzuki–Miyaura coupling in water extract of pomegranate ash, a bio-derived sustainable and renewable medium
Appa, Rama Moorhy,Prasad, S. Siva,Lakshmidevi, Jangam,Naidu, Bandameeda Ramesh,Narasimhulu, Manchala,Venkateswarlu, Katta
, (2019/08/12)
An agro waste-derived, ‘water extract of pomegranate ash’ (WEPA), has been utilized for the first time as a renewable medium for Pd(OAc)2-catalysed Suzuki–Miyaura cross-coupling at room temperature. This method offers a simple and sustainable synthesis of biaryls from aryl halides and arylboronic acids under ligand- and external base-free aerobic and ambient conditions. This method has been found effective for both activated and unactivated aryl halides in the production of biaryls with moderate to nearly quantitative yields. The protocol shows high chemoselectivity over identical/similar reactive sites in aryl halides (i.e. selectivity over identical halogens or different halogens of aryl halides). This method exhibits high regioselectivity, i.e. the selective reactivity of a halogen over other identical halogens at different positions on the aromatic nucleus. Therefore, we disclose here a clean, benign, substantial chemo- and regioselective and highly economic alternative method for the palladium-assisted synthesis of biaryls using an agro waste-derived medium.
Mechanism insight and scope of PEPPSI-catalyzed cross-coupling reaction between triarylbismuth and arylbromide
Cassirame, Bénédicte,Condon, Sylvie,Pichon, Christophe
, p. 94 - 102 (2016/10/04)
In this paper we report the first cross-coupling reaction of Ar3Bi with Ar'X mediated by Pd-NHC complexes by keeping the ability of Ar3Bi to transfer the three aryl moieties. Investigations were carried out in order to minimize the quantity of the side product Ar-Ar coming from the conversion of Ar3Bi. The results showed that PEPPSI IPr was a good catalyst precursor. Efforts were focussed on the rule of each additive such as PPh3 and the base. It was notably found that the presence of PPh3 (ratio PEPPSI IPr/PPh3: 1/1) was essential to keep the process efficient. Therefore NHC-Pd-PPh3 has been assumed as being the catalytic species. Under the optimized reaction conditions the concomitant formation of the undesired biaryl side product was restricted to its inherent formation consecutive to the reduction of the catalyst precursor to Pd(0). In a last study, the scope and the limitation of the new catalytic methodology were examined and a large range of unsymmetrical biaryl compounds Ar-Ar’ bearing various substituents from strongly electron-donating to electron-withdrawing ones have been prepared and fully characterized.
