Pd Nanoparticles Decorated on Hypercrosslinked Microporous Polymer: A Highly Efficient Catalyst for the Formylation of Amines through Carbon Dioxide Fixation

Abstract

CO2 fixation reaction is one of the most challenging chemical transformations not only in the context of environmental remediation but also for effective utilization of abundant carbon sources in nature. Here, we have stabilized palladium nanoparticles (NPs) at the surfaces of a hypercrosslinked porous polymer bearing carbazole and α,α′‐dibromo‐p‐xylene monomeric units to obtain a Pd@HMP‐1 nanocatalyst. The material has been thoroughly characterized by powder XRD, high‐resolution (HR)‐TEM, field‐emission (FE)‐SEM, Brunauer–Emmett–Teller (BET), thermogravimetric (TGA), and FTIR analysis. Pd@HMP‐1 showed excellent catalytic activity towards formylation of amines by carbon dioxide fixation under mild reaction conditions. The high surface area and nitrogen‐rich porous surface make the polymer a suitable support for the palladium nanoparticles and endow it with high recycling efficiency in this CO2 fixation reaction.

Pd NPs Decorated on POPs as Recyclable Catalysts for the Synthesis of 2‐Oxazolidinones from Propargylic Amines via Atmospheric Cyclizative CO2 Incorporation

“…The O 1s spectral region (Figure e) of the Pd@BBA‐2 material reveal a significant contribution in co‐ordination with the Pd‐NPs of the methoxy unit from the polymeric framework, as is evident from the O 1s binding energy positive shift compared with the parent POP . Figure describes the XPS image of Palladium 3d having two binding energy values at 334.8 eV and 340.5 eV, related to two splitting constituent 3d 5/2 and 3d 3/2 , respectively . Additionally, two bands in the 530–570 eV range of binding energy stands for the Palladium 3p 3/2 and 3p 1/2 .This outcome demonstrated the presence of palladium nanoparticles featuring zero oxidation state (Pd 0) in Pd@BBA‐2.…”

Supported Porous Nanomaterials as Efficient Heterogeneous Catalysts for CO2 Fixation Reactions

“…An unprecedented catalyst‐free formylation of amines by using hydrosilanes under atmospheric pressure of CO 2 at room temperature has been developed to the corresponding formamides by Lv et al . Very recently, we decorated Pd NPs onto a hyper‐cross‐linked microporous polymer for the N‐formylation of a wide range of amines using CO 2 under moderate pressure . N‐Formylated compounds like N‐methylformanilide are valuable intermediates for the synthesis of pharmaceutically demanding organic target molecules.…”

“…In Figure we have illustrated a possible mechanistic pathway for the N‐formylation of amines over Pd NPs supported over a hyper‐cross‐linked microporous polymer HMP‐1 . Here HMP‐1 has been synthesized through the Friedel–Crafts alkylation reaction between carbazole and α,α′‐dibromo‐ p ‐xylene in the presence of th Lewis acid FeCl 3 .…”

“…[56] Very recently,w ed ecorated Pd NPs onto ah yper-cross-linked microporous polymer for the N-formylation of aw ide range of amines using CO 2 under moderate pressure. [57] N-Formylated compounds like N-methylformanilide are valuablei ntermediates for the synthesis of pharmaceutically demanding organic targetm olecules.…”

“…[199,200] In Figure 6w eh ave illustrated ap ossible mechanistic pathway for the N-formylation of amines over Pd NPs supported over ah yper-cross-linked microporous polymer HMP-1. [57] Here HMP-1 has been synthesized through the Friedel-Crafts alkylation reactionb etween carbazole and a,a'-dibromo-p-xylene in the presence of th Lewis acid FeCl 3 .W hen HMP-1 is treated with Pd II in the presence of ethylene glycol the latter acts as a reducing agentf or the grafting of tiny Pd NPs at the porous surface. The nitrogen-donor sites of carbazole that is present in HMP-1 stabilizes the Pd NPsi ni ts vicinity as well as activating the CO 2 molecules, whereas the SiÀHb ond of Me 2 PhSiH is activated by surface-boundP dN Ps.…”