Cross-dehydrogenative C(sp³)–C(sp³) coupling via C–H activation using magnetically retrievable ruthenium-based photoredox nanocatalyst under aerobic conditions

Abstract

A robust, magnetically retrievable photoredox Ru-based heterogeneous nanocatalyst was fabricated for the highly regio-selective synthesis of N-aryl-tetrahydroisoquinoline derivatives.

Chemistry of magnetic covalent organic frameworks (MagCOFs): from synthesis to separation applications

“…Relatively inexpensive and simple silica coating not only minimizes the aggregation but also provides many potential benefits such as chemical inertness, high binding strength with iron-oxide core, robustness, possibility for further functionalization, etc. [88][89][90][91][92][93][94][95] Further, amino groups were introduced on the surface of Fe 3 O 4 @SiO 2 to obtain amino-modified Fe 3 O 4 @SiO 2 @NH 2 . Afterwards, the monomers, p-phenylenediamine (PPD) and trimesoyl chloride (TMC) were added to obtain carboxylic acid rich MagCOFs (Fe 3 O 4 @COFs-COOH).…”

An Earth-abundant cobalt based photocatalyst: visible light induced direct (het)arene C–H arylation and CO2 capture

“…24,25 In this context, the interest of researchers is continually focused on the design and development of readily recoverable, reusable and economically feasible photocatalysts that allow promising prospects of deploying an abundant, renewable and clean source of solar energy or visible light for multifaceted catalytic applications. [24][25][26] In light of our on-going interest in developing heterogeneous photocatalysts and our group's expertise in the field of heterogeneous catalysis, [27][28][29][30][31] we became inspired to develop a viable and efficient noble metal free heterogeneous photo catalytic system that exhibits high stability and easy processability. Subsequentially, we devoted our attention toward harnessing the synergistic effects of facile recoverability of magnetic nanoparticles and photoactive properties of Earth abundant metal-based complexes that can ultimately serve as competent photocatalysts to address the limitations associated with conventional photoredox based materials.…”

“…Initially, we fabricated magnetic nanoparticles (MNPs) of Fe 3 O 4 via a co-precipitation method following the previously reported protocol. 27 Here, the magnetic nanoparticles contribute to a high surface area-to-volume ratio and assist in accomplishing facile catalyst separation via the use of an external magnet. 32 Afterwards, Fe 3 O 4 was encapsulated with silica using TEOS as the precursor via a sol-gel approach to form silica@MNPs having excellent chemical, thermal and mechanical stabilities and ease of functionalization.…”

“…32 Afterwards, Fe 3 O 4 was encapsulated with silica using TEOS as the precursor via a sol-gel approach to form silica@MNPs having excellent chemical, thermal and mechanical stabilities and ease of functionalization. 27,33,34 The silica coated Fe 3 O 4 (SMNPs) were further amine functionalized with (3-aminopropyl)triethoxysilane (APTES) and anchored with the ligand 1-(4-acetylphenyl)-1H-pyrazole (Apz). It is interesting to note that various optimisation studies were carried out to synthesize 1-(4-acetylphenyl)-1H-pyrazole (Apz) in high yield utilizing K 3 PO 4 instead of expensive Cs 2 CO 3 utilized in previous literature precedents (Table S1 †).…”

“…1e). 27,41 UV-Vis (DRS) and fluorescence spectra have been recorded to investigate the optoelectronic properties of the Co@Apz@ASMNP photocatalyst. The shoulder peak in the range of 200-300 nm arises due to the spin-allowed singlet ligand-centered (LC) 1 π-π transitions of the ligands.…”