Reactivity of ketenyl anions towards ammonia

Abstract

Alkali metal ketenyls, [M(RCCO)], were found to exhibit diverging reactivities towards ammonia depending on the substitution pattern. Ketenyl anions with strong electron-withdrawing groups (R = CN or tosyl) react with NH₃ to form β-ketoamides, while the phosphinoyl substituted systems (R = Ph₂P(E), E = S, Se) activate all three N−H bonds, resulting in a trianionic triamide. This triamide exhibits a dimeric structure with the six potassium cations forming a unique planar triangular {K₆}⁶⁺ cluster.