Expedient Synthesis of E-Hydrazone Esters and 1H-Indazole Scaffolds through Heterogeneous Single-Atom Platinum Catalysis
Kian Ping Loh and Ming Joo Koh show an application of heterogeneous single-atom platinum catalysis.
Single-atom catalysts (SACs) with the distinct advantage of ultra-high performance-to-metal ratios have been actively explored on many energy-related frontiers. Professor Kian Ping Loh from the National University of Singapore claimed that despite their superior performance in gas-phase reactions, SACs are typically ineffective and rarely utilized to construct medicinally important structures under liquid-phase conditions. One such class of medicinally relevant molecules is that of the 1H-indazole compounds. Professor Ming Joo Koh, an expert in organic synthesis from the same school pointed out that access to 1H-indazoles requires the synthesis of stereodefined and unprotected E-α-hydrazone esters, which is often difficult to achieve by conventional strategies. Recently, the groups of Professor Loh and Professor Koh demonstrated that Pt single atoms anchored on defect-rich CeO2 nanorods (Pt1/CeO2) promote exceptionally E-selective hydrogenation of α-diazoesters to afford a wide assortment of E-α-hydrazone esters by the catalytic alcoholysis of ammonia borane (NH3·BH3).