Abdul Aziz Ali

A novel green protocol for ligand free Suzuki–Miyaura cross-coupling reactions in WEB at room temperature

A highly efficient green protocol for palladium acetate-catalysed ligand-free Suzuki–Miyaura cross-coupling reactions in neat ‘water extract of banana (WEB)’ was developed. This method offers a mild, efficient and highly economical alternative to the existing protocols since the reaction proceeds in WEB at room temperature in air at very short reaction times (5–90 min) under ‘ligand/external base/external promoter/organic medium’ free conditions.

Magnetically recoverable chitosan-stabilised copper–iron oxide nanocomposite material as an efficient heterogeneous catalyst for azide–alkyne cycloaddition reactions

Chitosan-stabilised copper–iron oxide nanocomposite material is found to be a very efficient recyclable/reusable heterogeneous catalyst for azide–alkyne cycloaddition reaction under mild conditions. The as-synthesized nanocomposite material is magnetically recoverable and reusable for a minimum of four cycles without significant loss in its catalytic activity. The catalytic system is found to be highly useful for the regioselective synthesis of a wide range of 1,2,3-triazoles from various azides and alkynes.

Pd(OAc)2 and (DHQD)2PHAL as a simple, efficient and recyclable/reusable catalyst system for Suzuki–Miyaura cross-coupling reactions in H2O at room temperature

Suzuki–Miyaura cross-coupling reaction catalyzed by Pd(OAc)2–(DHQD)2PHAL is a very simple, mild and efficient protocol for the synthesis of biaryls/heterobiaryls in neat H2O at room temperature. The catalyst system is recyclable/reusable and can be employed in several consecutive runs without significant loss in catalytic activity.

(DHQD)2PHAL ligand-accelerated Cu-catalyzed azide–alkyne cycloaddition reactions in water at room temperature

Herein, we have described, a ‘Click Chemistry’ protocol for the rapid synthesis of 1,2,3-triazoles in water. (DHQD)2PHAL has been found to be an excellent accelerating ligand for the copper(I)-catalyzed azide–alkyne cycloaddition reaction under air. The procedure is simple, efficient, environmentally-friendly and the products were isolated in excellent yields with high purity.

‘On-water’ organic synthesis: a green, highly efficient, low cost and reusable catalyst system for biaryl synthesis under aerobic conditions at room temperature

A simple, greener, efficient, low cost and mild protocol has been developed for sucrose assisted palladium-catalyzed Suzuki reactions in water at room temperature under aerobic conditions. The results demonstrate that the sucrose played a crucial role making this protocol highly efficient. The PdCl2/sucrose/K2CO3/H2O system showed superb catalytic activity towards the Suzuki reaction of a wide range of aryl/heteroaryl halides with different substituted phenylboronic acids. This method offers an attractive alternative to the existing protocols since the reaction proceeds in aqueous media at room temperature with operational simplicity, shorter reaction time, cost-effectiveness and provides the products in high yields. The catalytic system is highly recyclable, allowing the reuse of the palladium catalyst in subsequent catalytic runs without significant loss of activity.

Facile route for the regioselective synthesis of 1,4-disubstituted 1,2,3-triazole using copper nanoparticles supported on nanocellulose as recyclable heterogeneous catalyst

In this work, a green and efficient methodology has been developed for the synthesis of 1,2,3-triazoles by ‘copper nanoparticles supported on nanocellulose (CuNPs/NC)-catalyzed azide-alkyne cycloaddition reaction in glycerol, an environmentally benign solvent, with excellent yields. The present catalyst was characterized by TEM, XRD, SEM-EDX and FT-IR spectroscopy. The reusability of the prepared nanocatalyst was examined up to five times without significant loss of catalytic activity.Graphical Abstract:SYNOPSIS: A catalyst of copper nanoparticle supported on highly crystalline nanocellulose was prepared and was effectively used for the important regioselective synthesis of 1,4-disubstituted 1,2,3-triazole from the 1,3-dipolar cycloaddition of various azides and alkynes.

CTAB promoted CuI catalyzed green and economical synthesis of 1,4-disubstituted-1,2,3-triazoles

ABSTRACT A practical, straightforward, and highly efficient CuI mediated green protocol for the regioselective synthesis of 1,4-disubstituted-1,2,3-triazole was developed using cetyltrimethylammonium bromide as a cheap additive in good to excellent yields. Low catalyst loadings, environmentally friendly solvent, wide substrate scope and short reaction times at room temperature make this strategy more accessible and safe. GRAPHICAL ABSTRACT