Supported Pd−Au bimetallic catalysts (BMCs) have attracted remarkable research interest because they can efficiently execute various important organic transformations. The major concern for launching Pd−Au bimetallic catalysis is either to perform the reaction with good atom economy under low catalyst/ metal loading or to introduce a reaction, which cannot be performed by its monometallic variants. The supports being applied for Pd−Au alloy also have been examined for their crucial role to perform a particular reaction accredited to combined synergistic effects in the catalyst. The optimized tuning between the catalyst support and the Pd/Au ratio always have been a deciding key factor for selectivity, stability, and activity of these catalysts as suggested by various mechanistic studies. Herein, we have summarized the recent advances in supported Pd−Au BMCs in terms of design strategies, characterizations for deep insight mechanistic study during the reaction course. This Review begins with a brief history and adopted methods for preparation of these catalysts followed by categorization of supporting material being applied either directly or after modification. Furthermore, quick glances of catalyst characterization, effects on conversion and selectivity, catalyst activation, and deactivation under the studied reaction parameters for respective organic transformations also have been included in the above-mentioned sections. The main purpose of catalyst development is to accomplish easy access of tedious reactions with good conversion rate and selectivity toward desired product. Therefore, in view of the application part for Pd−Au BMCs, we have tried to cover all basic and important organic reactions along with their substrate scope range and mechanistic studies. This present Review could be really useful for researchers working in this dimension via providing them a clear catalyst design idea, preparation method, support selection strategy, and right substrate screening for carrying out the targeted synthetic transformation.

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The polystyrene supported palladium-gold (PdÀ Au@PS) catalyst was prepared and well characterized by HR-TEM, EDX, Elemental Mapping, XPS and P-XRD analysis. The PdÀ Au@PS NPs displayed the superior catalytic activity than their monometallic forms. First time, the catalyst was applied for methylthioesterification reaction of aryl iodides with oxalic acid and DMSO as in situ carbon monoxide (CO) and methyl mercaptan (CH 3 SH) precursor. Yet, there is no report available where DMSO has been applied as CH 3 SH source for methylthioester synthesis. The CH 3 SH and CO are likely to poison the metal catalyst whereas in PdÀ Au@PS catalyst, the beneficial inter-electronic interactions between Pd and Au metals makes the catalyst highly reactive, poisoning resistant and recyclable during the transformation. Moreover, the developed protocol exhibits excellent functional group tolerance for various aryl iodides to delivered the desired products in moderate to very good yields.