Reactions of a geminal Sc/P Lewis pair with pyridotetrazole and beyond

Abstract

Frustrated Lewis pair (FLP) chemistry has undergone remarkable growth, among which rare-earth metal-based Lewis pairs have exhibited unique reactivity in recent years. Herein, treatment of the intramolecular Sc/P Lewis pair, i.e., (ArO)₂ScN(^tBu)PPh₂ (1, Ar = 2,6-^tBu₂-C₆H₃), with pyridotetrazole resulted in the formation of an FLP nitrene adduct with N₂ elimination, offering additional insights into the mechanism of transition-metal-catalyzed denitrogenative annulation of pyridotetrazole. Reactions of complex 1 with 1,3,5-triazine and benzo[c]cinnoline generated FLP-type products via Sc/P 1,2-addition to the CN bond and the NN bond, respectively. Furthermore, treatments of 1 with phenylacetylene, diazo, and azide compounds were also investigated, leading to the formation of a variety of metallacyclic complexes displaying typical FLP behaviors.