Synthesis of Collidine from Dinitrogen via a Tungsten Nitride
Lukas Eberle, Joachim Ballmann
Abstract
The synthesis of pyridines from dinitrogen in homogeneous solution is known to be challenging considering that an N 2 cleavage step needs to be combined with two N–C coupling steps. Herein, a tungsten complex bearing a tailor-made 2,2′-( t Bu 2 As) 2 -substituted tolane ligand scaffold was shown to split N 2 to afford the corresponding tungsten nitride, which is not the case for the corresponding ( i Pr 2 As) 2 -substituted derivative. The former nitride was then reacted with 2,4,6-trimethylpyrylium triflate, which led to the formation of a tungsten oxo complex, along with collidine. Over the course of this reaction, the O atom of the pyrylium starting material was replaced with an N atom via a hitherto unprecedented skeletal editing process.