Tungsten anchored onto functionalized SBA-15: an efficient catalyst for diastereoselective synthesis of 2-azapyrrolizidine alkaloid scaffolds

Abstract

We used a novel hybrid catalyst in chemo-, regio-, and diastereoselective multi-component reactions (MCR).

Green sonosynthesis of pyridopyrimidines using heterogeneous Pd‐containing catalysts anchored on a hybrid organic–inorganic surface of SBA‐15

“…Two secondary high‐order peaks with lower intensities corresponding to (1 1 0) and (2 0 0) approve 2D‐hexagonal planes of the mesoporous. [ 24,25 ] On modification with ligand and metal, the intensities of the peaks are decreased that can be related to occur the silylation inside the mesopores of SBA‐15. The presence of similar peaks for Pd/PBMBI‐SBA‐15 indicates that the structural ordering of SBA‐15 is not diminished during the silylation procedure.…”

“…The hexagonal pore structure of SBA-15 has been produced using pluronic 123 triblock copolymers (EO20-PO70-EO20) by the procedure as reported in the previous paper. [24] 3.4 | Organofunctionalization of SBA-15…”

A decennary update on applications of metal nanoparticles (MNPs) in the synthesis of nitrogen- and oxygen-containing heterocyclic scaffolds

“…Tungsten immobilized on SBA-15 [W(IV)/NNBIA-SBA-15] catalyzed Knoevenagel-Michael-5-exo-dig cyclization from the MCR between hydantoin (298), 29b and benzaldehydes (21a) or isatins (5c) led to the synthesis of 7-phenyl-2,3,7,7a-tetrahydro-1H-pyrrolo[1,2-c]imidazole (299) or spirooxindole-2azapyrrolizidine (300) (Scheme 187). 335 Chlorofunctionalized SBA-15, which was synthesized by the treatment of SBA-15 and (3-chloropropyl)triethoxysilane, was later treated with N,N 0 -(ethane-1,2-diyl)bis(2-aminobenzamide) (NNBIA) and WCl 6 for the covalent graing of tungsten to obtain the nal NPs. The ltered catalysts at the end of the reaction were recycled for up to ve runs without loss in its catalytic activity.…”

“…Aluminosulfonic acid (ASA) NPs as a Brønsted acid catalyzed the Biginelli reactions of b-ketoesters (63i), aldehydes (2) and (thio)urea (22a) for the synthesis of dihydropyrimidinones (172g) under solvent-free conditions at 70 C (Scheme 233). 413 The same protocol was also explored for the synthesis of Biginelli-like products such as octahydroquinazolinones (334), pyrimido [4,5-d]pyrimidines (335) and tetrahydropyrimidines (336) in excellent yields. The treatment of sodium aluminate with chlorosulfonic acid resulted in the formation of ASA.…”

Facile synthesis of pyrazolopyridine pharmaceuticals under mild conditions using an algin-functionalized silica-based magnetic nanocatalyst (Alg@SBA-15/Fe3O4)

“…They investigated the efficiency of this catalyst in the synthesis of 2-azapyrrolizidine alkaloids, which have different biological properties. 34 In 2019, by grafting the nickel Schiff base complex on the SBA-15 surface, Noroozi et al prepared a nano-catalyst called Ni( ii )-Schiff base/SBA-15. It was an eco-friendly, and effective catalyst for the synthesis of 2-amino-4-aryl-5-oxo-4H,5H-pyrano[3,2- c ]chromene-3-carbonitriles derivatives through a tandem reaction.…”