Oxidative Metalation as a Route to Size-Mismatched Macrocyclic Complexes: Osmium Corroles

Heavy‐element corroles are of great interest as optical sensors, near‐IR dyes, phosphors, organic light‐emitting diodes, and anticancer compounds. Insertion of 5d metals into corroles, however, is often a difficult and unpredictable process. Against this backdrop, oxidative metalation of meso triarylcorroles with [Os3(CO)12]/NaN3 in refluxing 1:2 diethylene glycol monomethyl ether/glycol has provided a convenient and relatively high‐yielding route to nitridoosmium(VI) corroles, three of which could be characterized with single‐crystal X‐ray structure analysis. Last man standing! After the synthesis of platinum corroles, osmium was the last remaining middle and late 5d metal to be inserted into the contracted porphyrin analogue. Oxidative metalation has now provided a moderately high‐yielding route to osmium corroles. DEGME=diethylene glycol monomethyl ether.