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To safeguard the development of nuclear energy, practical techniques for capture and storage of radioiodine are of critical importance but remains a significant challenge. Here we report the synergistic effect...

Ligands are the most commonly used means to control the regioselectivity of organic reactions. It is very important to develop new regioselective control methods for organic synthesis. In this study, we designed and synthesized a single-atomic-site catalyst (SAC), namely, Cu1-TiC, with strong electronic metal–support interaction (EMSI) effects by studying various reaction mechanisms. π cloud back-donation to the alkyne on the metal catalytic intermediate was enhanced during the reaction by using transient electron-rich characteristics. In this way, the reaction achieved highly linear-E-type regioselective conversion of electronically unbiased alkynes and completely avoided the formation of branched isomers (ln:br >100:1, TON up to 612, 3 times higher than previously recorded). The structural elements of the SACs were designed following the requirements of the synthesis mechanism. Every element in the catalyst played an important role in the synthesis mechanism. This demonstrated that the EMSI, which is normally thought to be responsible for the improvement in catalytic efficiency and durability in heterogeneous catalysis, now first shows exciting potential for regulating the regioselectivity in homogeneous catalysis.

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Transition metal-catalyzed carbenoid insertion of hydroxyl groups represents a robust and versatile method to forge C-O bonds. Achieving site-selective functionalization of alcohols using this transformation has undoubted synthetic value, but remains challenging. Here we report a strategy exploitng an engineered heterogeneous iridium single atom (Ir-SA) catalyst for selective carbenoid O-H insertion, thus providing opportunities in merging material science and catalysis for organic transformations. This catalytic protocol delivers excellent selectivities (up to 99:1) for functionalization of aliphatic over phenolic O-H bonds, even in cases where the analogous homogeneous catalyst, Ir(ttp)COCl, provided modest preferences. DFT calculations suggest that the site-selectivity derives from the lower oxidation state of iridium metal center in the heterogeneous catalyst and its impact on the absorption energies of catalytic species. These results comprise an example of a heterogeneous single atom catalyst providing superior site-selectivity and provide a complementary strategy to address challenges in catalysis for organic synthesis.