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 C=N bond and the N=N 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.