Butyllithium-induced cyclotrimerisation reactions of organic nitriles: solvent dependency, crystal and solution structures of lithio triazine intermediates and an unexpected rearrangement of dihydrotriazino anions

Abstract

Sequential addition of Bu^tCN and PhCN (2 equiv.) to BuⁿLi in the presence of tetrahydrofuran (THF) produces an isolable lithio 1,4 dihydrotriazine tris(THF) solvate, characterized by both NMR spectroscopic X-ray crystallographic methods, which converts to a 1,2-dihydro arrangement on methanolysis.