Pd nanoparticles Incarcerated in Aluminium Oxy‐Hydroxide: An Efficient and Recyclable Heterogeneous Catalyst for Selective Knoevenagel Condensation

Abstract

Knoevenagel condensation between aryl aldehyde derivatives with malononitrile was successfully achieved using commercially available Pd/AlO(OH) nanoparticles (0.5 wt% Pd) in an aqueous medium. All benzylidenemalononitrile (BMN) derivatives were obtained promptly (8‐60 min) with high selectivity and yields of over 99 % in a mixture of H2O/MeOH (v/v=1/2) at room temperature. Moreover, when benzoyl chloride derivatives were utilized instead of aryl aldehyde derivatives, medium amounts of the expected products were yielded. Before the reaction and after five reuses, characterization of the Pd/AlO(OH) nanoparticles was carried out via X‐ray diffraction and scanning electron microscopy analysis. The BMN derivative characterization was accomplished using the 1H NMR and 13C NMR spectra. In order to optimize the reaction conditions, the parametric effects of the solvent type and catalyst amount were examined. Consequently, the PdAlO(OH) NPs were used for the first time in the Knoevenagel condensation. A novel, practical and eco‐friendly process was developed for Knoevenagel condensation in the presence of Pd/AlO(OH) nanoparticles.

Introducing A New Class of Sulfonyl Fluoride Hubs via Radical Chloro‐Fluorosulfonylation of Alkynes

“…In addition, control experiments (entries 10-12) suggested that photocatalyst, argon atmosphere,and light irradiation are all crucial to the reaction. [10,14] The Reaction Scope of the Radical Chloro-Fluorosulfonyl Difunctionalization of Alkynes. Having the optimized reaction conditions (fac-Ir(ppy) 3 as the photocatalyst, ether as the solvent, blue LEDs irradiation) in hand, we moved to the investigation of the reaction scope of this radical chlorofluorosulfonylation reaction with different alkynes (Table 2).…”

Designing of Ultrafine PdNPs Immobilized Pyridinic‐NDoped Carbon and Evaluation of its Catalytic Potential for Konevenagel Condensation, Synthesis of 4H‐pyran Derivatives and Nitroreduction

“…Benzylidenemalononitrile (BMN) derivatives act as intermediates for the generation of many biologically important molecules such as enzyme inhibitors, carbohydrates and heterocycles . Already reported method for the Knoevenagel condensation by palladium suffers from certain limitations such as less yield, longer reaction time and tedious workup procedure . 4 H ‐pyran derivatives and its analogues heterocyclic compounds are mainly an important class of oxygen‐containing skeleton that constitute the core motif of various natural products .…”

Synthesis of N-Arylimidazole Derivatives From Imidazole and Arylhalides in the Presence of Recoverable Pd/AlO(OH) NPs

“…Scheme 1: Active ingredients of some drugs containing imidazole ring some bioactive biphenyl derivatives. [6] aldehyde [21] and azido compounds [22] and in the knoevenagle condensation [23] dehalogenation of aryl halides [23] and in the oxidation of benzylic alcohols [24]. Herein, the formation of N-aryl imidazoles was carried out using ultrasonic conditions and PdAlO (OH) NPs, which is highly stable and reusable in eco-friendly solvent mixture such as H 2 O / IPA.…”