Aminomethylation Reaction of <i>ortho</i>-Pyridyl C–H Bonds Catalyzed by Group 3 Metal Triamido Complexes
2015-01-21T00:00:00Z (GMT) by
Tris[<i>N</i>,<i>N</i>-bis(trimethylsilyl)amido] complexes of group 3 metals, especially yttrium and gadolinium, served as catalysts for <i>ortho</i>-C–H bond addition of pyridine derivatives and N-heteroaromatics into the CN double bond of nonactivated imines to afford the corresponding aminomethylated products. Addition of catalytic amounts of secondary amines, such as dibenzylamine, dramatically improved the catalytic activity through the formation of a mixed ligated complex such as [(Me<sub>3</sub>Si)<sub>2</sub>N]<sub>2</sub>Y(NBn<sub>2</sub>)(THF) (<b>4</b>). Furthermore, kinetic studies using the isolated complex <b>4</b> provided a plausible reaction mechanism by which coordination of two pyridine derivatives afforded a penta-coordinated species as a key step.