A new nanomagnetic Pd-Co bimetallic alloy as catalyst in the Mizoroki–Heck and Buchwald–Hartwig amination reactions in aqueous media

Abstract

A Pd-Co bimetallic alloy encapsulated in melamine-based dendrimer supported on magnetic nanoparticles denoted as γ-Fe2O3@MBD/Pd-Co was synthesized by a facile co-complexation-reduction method and characterized sufficiently. The catalytic evaluation of γ-Fe2O3@MBD/Pd-Co showed promising results in the Mizoroki–Heck and Buchwald–Hartwig amination reactions of various iodo-, bromo- and challenging chloroarenes in aqueous media. The synergetic cooperative effect of both Pd and Co and dispersion of the catalyst in water due to the encapsulation of γ-Fe2O3 by melamine-based dendrimer lead to high catalytic performance compared with the monometallic counterparts. The dispersion of the magnetic catalyst also facilitates the recovery and reuse of the catalyst by ten consecutive extraction and final magnetic isolation with no loss of catalytic activity, keeping its structure unaltered.

Heterogenization of Cobalt on Nanostructured Magnetic Covalent Triazine Framework: Effective Catalyst for Buchwald-Hartwig N-Arylation, Reduction, and Oxidation Reactions

“…Then, the reaction proceeds by the coordination of aniline with intermediate (I) to form intermediate (II). Finally, the product is formed by base-assisted elimination of X-H from intermediate (III) by subsequent reductive elimination and catalyst regeneration . In the oxidation process, TBHP cleaves to yield the peroxo compound and tert-butanol ( t -BuOH) resulting in the peroxo surface species.…”

Unification of Ullmann and Kharasch coupling: acid promoted CuI catalysed C–N coupling protocols under ligand, base and solvent free conditions

“…The substrate scope was further expanded to piperidine (11)(12)(13)(14)(15)(16)(17) and their derivatives, i.e. morpholine (18)(19)(20) and piperazine (21-23) (Fig.…”

“…In the past decades, there were several reports of bimetallic strategies which utilise Ni-Cu, Pd-Au, Pd-Fe, Pd-Co and Pd-Cu, all of which strongly demand the presence of base for the desired transformation. [8][9][10][11][12] The presence of strong bases in C-N coupling reactions gives rise to interference with base sensitive and electron withdrawing groups, and also induces precipitation, restricting the use of such methodologies in bulk batch reactions and in flow or micro-channel reactors. Recently Patil et al, (2019), followed by Joshi et al, (2020), reported a base free methodology for C-N coupling reactions which addressed the raised issues to certain extents.…”

Cobalt isatin-Schiff-base derivative of MOF as a heterogeneous multifunctional bio-photocatalyst for sunlight-induced tandem air oxidation condensation process

“…In continue of our studies on the introducing new heterogeneous catalysts for the organic transformations 35 – 37 , herein, in this paper, we have applied a MOF modified with cobalt-complex 38 [Co-isatin-Schiff-base-MIL-101(Fe)] as a new heterogeneous multifunctional bio-photocatalyst for the synthesis of benz-imidazoles/-oxazoles/-thiazoles, and benzylidene malononitrile by TOP starting from readily available alcohols. The photocatalytic antibacterial activity of Co-isatin-Schiff-base-MIL-101(Fe) against E. coli, S. aureus and S. pyogenes was also studied under sunlight illumination.…”