A Well-Defined Calcium Compound Catalyzes Trimerization of Arylisocyanates into 1,3,5-Triarylisocyanurates

We report the synthesis of a calcium complex (2) bearing a tetradentate monoanionic ligand with a diaminoethane core and phenolate and pyridine peripheral donors. Single crystal X-ray studies on 2 revealed that LiI was also co-crystallized, leading to a four-membered ring with four different elements. 2 was found to be an efficient catalyst for the cyclotrimerization of a variety of aromatic isocyanates under mild conditions.

Automated summary

We report the synthesis of a calcium complex that acts as an efficient catalyst for the cyclotrimerization of various aromatic isocyanates under mild conditions. Single crystal X-ray studies on the complex revealed the presence of LiI, forming a four-membered ring with four different elements.