Preparation and Application of WELAN to Pd(OAc)2-Catalyzed Suzuki–Miyaura Cross-Coupling Reaction
摘要
An extremely efficient green protocol for palladium acetate-catalysed ligand-free Suzuki–Miyaura cross-coupling reactions of aryl/heteroaryl bromides with aryl/substitute aryl boronic acids in neat ‘Water Extract of Leaf Ash of Neem’ (WELAN)’ was developed. This method offers a simple, mild, efficient and highly cost-effective alternative to the existing protocols since the reaction proceeds in natural feedstock WELAN at room temperature in air at very short reaction times (5–60 min) under ligand/external base/promoter/organic medium free conditions. Here WELAN has been found to be the effective base and reaction medium for this cross-coupling reaction with high turnover number (TON). This manuscript also theoretically depicts the probable mechanism of WELAN catalysed cross-coupling reaction.
Graphical Abstract