Flash Communication: An Inorganic Version of Alkyne–Azide Cycloaddition: Click-Like Reactions of an o-Carboranyl Iminoborane with Organic Azides

The concept of inorganic-alkyne-based click ( ia click) was introduced. Analogous to the azide–alkyne cycloaddition, o -carboranyl iminoborane 1, an inorganic alkyne, readily underwent cycloaddition with a variety of azides at room temperature and under catalyst-free conditions. This offered a modular synthetic approach to o -carboranyl tetrazaboroles 2a – 2h in excellent yields. Stability tests of 2a – 2h were performed. These compounds displayed considerable thermal stability, with decomposition temperatures in the range of 195.0–270.8 °C, determined by STA. Air stability tests in the solid state showed that the 1-alkyl derivatives were stable for hours, while the 1-aryl derivatives were stable for weeks. Therefore, upon straightforward incorporation of o -carborane units into organic frameworks, ia click strategy opens a new avenue for the construction of stable o -carborane-based functional molecules with potential for diverse applications.